sql_select.cc 301 KB
Newer Older
1
/* Copyright (C) 2000-2004 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/* mysql_select and join optimization */

20
#ifdef USE_PRAGMA_IMPLEMENTATION
bk@work.mysql.com's avatar
bk@work.mysql.com committed
21 22
#pragma implementation				// gcc: Class implementation
#endif
23 24

#include "mysql_priv.h"
bk@work.mysql.com's avatar
bk@work.mysql.com committed
25
#include "sql_select.h"
sasha@mysql.sashanet.com's avatar
sasha@mysql.sashanet.com committed
26

bk@work.mysql.com's avatar
bk@work.mysql.com committed
27 28 29 30 31
#include <m_ctype.h>
#include <hash.h>
#include <ft_global.h>

const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
32
			      "MAYBE_REF","ALL","range","index","fulltext",
33
			      "ref_or_null","unique_subquery","index_subquery"
34
};
bk@work.mysql.com's avatar
bk@work.mysql.com committed
35

36
static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
37
static bool make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
38
				 DYNAMIC_ARRAY *keyuse);
39 40
static bool update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,
				JOIN_TAB *join_tab,
41 42
                                uint tables, COND *conds,
				table_map table_map, SELECT_LEX *select_lex);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
43 44
static int sort_keyuse(KEYUSE *a,KEYUSE *b);
static void set_position(JOIN *join,uint index,JOIN_TAB *table,KEYUSE *key);
45 46
static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, KEYUSE *org_keyuse,
			       table_map used_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
47 48 49 50 51 52
static void find_best_combination(JOIN *join,table_map rest_tables);
static void find_best(JOIN *join,table_map rest_tables,uint index,
		      double record_count,double read_time);
static uint cache_record_length(JOIN *join,uint index);
static double prev_record_reads(JOIN *join,table_map found_ref);
static bool get_best_combination(JOIN *join);
53 54
static store_key *get_store_key(THD *thd,
				KEYUSE *keyuse, table_map used_tables,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
55 56 57 58 59
				KEY_PART_INFO *key_part, char *key_buff,
				uint maybe_null);
static bool make_simple_join(JOIN *join,TABLE *tmp_table);
static bool make_join_select(JOIN *join,SQL_SELECT *select,COND *item);
static void make_join_readinfo(JOIN *join,uint options);
60
static bool only_eq_ref_tables(JOIN *join, ORDER *order, table_map tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
61 62 63
static void update_depend_map(JOIN *join);
static void update_depend_map(JOIN *join, ORDER *order);
static ORDER *remove_const(JOIN *join,ORDER *first_order,COND *cond,
64
			   bool change_list, bool *simple_order);
65
static int return_zero_rows(JOIN *join, select_result *res,TABLE_LIST *tables,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
66 67
			    List<Item> &fields, bool send_row,
			    uint select_options, const char *info,
68 69
			    Item *having, Procedure *proc,
			    SELECT_LEX_UNIT *unit);
70 71
static COND *optimize_cond(THD *thd, COND *conds,
			   Item::cond_result *cond_value);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
72 73 74
static bool const_expression_in_where(COND *conds,Item *item, Item **comp_item);
static bool open_tmp_table(TABLE *table);
static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
75
				    ulong options);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
76 77 78 79
static int do_select(JOIN *join,List<Item> *fields,TABLE *tmp_table,
		     Procedure *proc);
static int sub_select_cache(JOIN *join,JOIN_TAB *join_tab,bool end_of_records);
static int sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records);
80
static int flush_cached_records(JOIN *join,JOIN_TAB *join_tab,bool skip_last);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
81 82 83 84 85 86 87 88 89
static int end_send(JOIN *join, JOIN_TAB *join_tab, bool end_of_records);
static int end_send_group(JOIN *join, JOIN_TAB *join_tab,bool end_of_records);
static int end_write(JOIN *join, JOIN_TAB *join_tab, bool end_of_records);
static int end_update(JOIN *join, JOIN_TAB *join_tab, bool end_of_records);
static int end_unique_update(JOIN *join,JOIN_TAB *join_tab,
			     bool end_of_records);
static int end_write_group(JOIN *join, JOIN_TAB *join_tab,
			   bool end_of_records);
static int test_if_group_changed(List<Item_buff> &list);
90
static int join_read_const_table(JOIN_TAB *tab, POSITION *pos);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
91 92 93 94
static int join_read_system(JOIN_TAB *tab);
static int join_read_const(JOIN_TAB *tab);
static int join_read_key(JOIN_TAB *tab);
static int join_read_always_key(JOIN_TAB *tab);
95
static int join_read_last_key(JOIN_TAB *tab);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
96 97 98 99 100
static int join_no_more_records(READ_RECORD *info);
static int join_read_next(READ_RECORD *info);
static int join_init_quick_read_record(JOIN_TAB *tab);
static int test_if_quick_select(JOIN_TAB *tab);
static int join_init_read_record(JOIN_TAB *tab);
101 102 103 104 105 106
static int join_read_first(JOIN_TAB *tab);
static int join_read_next(READ_RECORD *info);
static int join_read_next_same(READ_RECORD *info);
static int join_read_last(JOIN_TAB *tab);
static int join_read_prev_same(READ_RECORD *info);
static int join_read_prev(READ_RECORD *info);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
107 108
static int join_ft_read_first(JOIN_TAB *tab);
static int join_ft_read_next(READ_RECORD *info);
109 110
static int join_read_always_key_or_null(JOIN_TAB *tab);
static int join_read_next_same_or_null(READ_RECORD *info);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
111 112 113
static COND *make_cond_for_table(COND *cond,table_map table,
				 table_map used_table);
static Item* part_of_refkey(TABLE *form,Field *field);
serg@serg.mylan's avatar
serg@serg.mylan committed
114
static uint find_shortest_key(TABLE *table, const key_map *usable_keys);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
115
static bool test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,
116
				    ha_rows select_limit, bool no_changes);
117 118 119 120
static bool list_contains_unique_index(TABLE *table,
                          bool (*find_func) (Field *, void *), void *data);
static bool find_field_in_item_list (Field *field, void *data);
static bool find_field_in_order_list (Field *field, void *data);
121
static int create_sort_index(THD *thd, JOIN *join, ORDER *order,
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
122
			     ha_rows filesort_limit, ha_rows select_limit);
123 124
static int remove_duplicates(JOIN *join,TABLE *entry,List<Item> &fields,
			     Item *having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
125
static int remove_dup_with_compare(THD *thd, TABLE *entry, Field **field,
126
				   ulong offset,Item *having);
127
static int remove_dup_with_hash_index(THD *thd,TABLE *table,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
128
				      uint field_count, Field **first_field,
129
				      ulong key_length,Item *having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
130 131 132
static int join_init_cache(THD *thd,JOIN_TAB *tables,uint table_count);
static ulong used_blob_length(CACHE_FIELD **ptr);
static bool store_record_in_cache(JOIN_CACHE *cache);
133 134
static void reset_cache_read(JOIN_CACHE *cache);
static void reset_cache_write(JOIN_CACHE *cache);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
135 136 137 138
static void read_cached_record(JOIN_TAB *tab);
static bool cmp_buffer_with_ref(JOIN_TAB *tab);
static bool setup_new_fields(THD *thd,TABLE_LIST *tables,List<Item> &fields,
			     List<Item> &all_fields,ORDER *new_order);
139 140
static ORDER *create_distinct_group(THD *thd, Item **ref_pointer_array,
                                    ORDER *order, List<Item> &fields,
141
				    bool *all_order_by_fields_used);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
142 143 144
static bool test_if_subpart(ORDER *a,ORDER *b);
static TABLE *get_sort_by_table(ORDER *a,ORDER *b,TABLE_LIST *tables);
static void calc_group_buffer(JOIN *join,ORDER *group);
145
static bool make_group_fields(JOIN *main_join, JOIN *curr_join);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
146
static bool alloc_group_fields(JOIN *join,ORDER *group);
147
// Create list for using with tempory table
148
static bool change_to_use_tmp_fields(THD *thd, Item **ref_pointer_array,
149 150 151 152 153 154 155 156
				     List<Item> &new_list1,
				     List<Item> &new_list2,
				     uint elements, List<Item> &items);
// Create list for using with tempory table
static bool change_refs_to_tmp_fields(THD *thd, Item **ref_pointer_array,
				      List<Item> &new_list1,
				      List<Item> &new_list2,
				      uint elements, List<Item> &items);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
157 158
static void init_tmptable_sum_functions(Item_sum **func);
static void update_tmptable_sum_func(Item_sum **func,TABLE *tmp_table);
159
static void copy_sum_funcs(Item_sum **func_ptr, Item_sum **end);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
160
static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab);
161
static bool init_sum_functions(Item_sum **func, Item_sum **end);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
162
static bool update_sum_func(Item_sum **func);
163
static void select_describe(JOIN *join, bool need_tmp_table,bool need_order,
164
			    bool distinct, const char *message=NullS);
165
static Item *remove_additional_cond(Item* conds);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
166

167

168 169 170 171 172 173 174 175
/*
  This handles SELECT with and without UNION
*/

int handle_select(THD *thd, LEX *lex, select_result *result)
{
  int res;
  register SELECT_LEX *select_lex = &lex->select_lex;
176 177
  DBUG_ENTER("handle_select");

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
178
  if (select_lex->next_select() || select_lex->master_unit()->fake_select_lex)
179
    res=mysql_union(thd, lex, result, &lex->unit);
180
  else
181 182 183 184 185 186 187 188 189 190 191
    res= mysql_select(thd, &select_lex->ref_pointer_array,
		      (TABLE_LIST*) select_lex->table_list.first,
		      select_lex->with_wild, select_lex->item_list,
		      select_lex->where,
		      select_lex->order_list.elements +
		      select_lex->group_list.elements,
		      (ORDER*) select_lex->order_list.first,
		      (ORDER*) select_lex->group_list.first,
		      select_lex->having,
		      (ORDER*) lex->proc_list.first,
		      select_lex->options | thd->options,
192
		      result, &(lex->unit), &(lex->select_lex));
193

194 195 196
  /* Don't set res if it's -1 as we may want this later */
  DBUG_PRINT("info",("res: %d  report_error: %d", res,
		     thd->net.report_error));
197
  if (thd->net.report_error || res<0)
198
  {
199 200
    result->send_error(0, NullS);
    result->abort();
201
    res= 1;					// Error sent to client
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
202
  }
203
  DBUG_RETURN(res);
204 205
}

206

207
/*
208
  Function to setup clauses without sum functions
209
*/
210 211
inline int setup_without_group(THD *thd, Item **ref_pointer_array,
			       TABLE_LIST *tables,
212 213 214 215 216 217
			       List<Item> &fields,
			       List<Item> &all_fields,
			       COND **conds,
			       ORDER *order,
			       ORDER *group, bool *hidden_group_fields)
{
monty@mysql.com's avatar
monty@mysql.com committed
218 219 220 221 222
  bool save_allow_sum_func;
  int res;
  DBUG_ENTER("setup_without_group");

  save_allow_sum_func= thd->allow_sum_func;
223
  thd->allow_sum_func= 0;
monty@mysql.com's avatar
monty@mysql.com committed
224 225 226 227 228
  res= (setup_conds(thd, tables, conds) ||
        setup_order(thd, ref_pointer_array, tables, fields, all_fields,
                    order) ||
        setup_group(thd, ref_pointer_array, tables, fields, all_fields,
                    group, hidden_group_fields));
229
  thd->allow_sum_func= save_allow_sum_func;
monty@mysql.com's avatar
monty@mysql.com committed
230
  DBUG_RETURN(res);
231 232
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
233
/*****************************************************************************
234 235
  Check fields, find best join, do the select and output fields.
  mysql_select assumes that all tables are already opened
bk@work.mysql.com's avatar
bk@work.mysql.com committed
236 237
*****************************************************************************/

238
/*
monty@mysql.com's avatar
monty@mysql.com committed
239
  Prepare of whole select (including sub queries in future).
240 241 242
  return -1 on error
          0 on success
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
243
int
244 245 246 247
JOIN::prepare(Item ***rref_pointer_array,
	      TABLE_LIST *tables_init,
	      uint wild_num, COND *conds_init, uint og_num,
	      ORDER *order_init, ORDER *group_init,
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
248
	      Item *having_init,
249 250
	      ORDER *proc_param_init, SELECT_LEX *select_lex_arg,
	      SELECT_LEX_UNIT *unit_arg)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
251
{
252
  DBUG_ENTER("JOIN::prepare");
253

254 255 256 257
  // to prevent double initialization on EXPLAIN
  if (optimized)
    DBUG_RETURN(0);

258 259 260 261 262 263
  conds= conds_init;
  order= order_init;
  group_list= group_init;
  having= having_init;
  proc_param= proc_param_init;
  tables_list= tables_init;
264
  select_lex= select_lex_arg;
265
  select_lex->join= this;
266
  union_part= (unit_arg->first_select()->next_select() != 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
267

268
  thd->lex->current_select->is_item_list_lookup= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
269 270
  /* Check that all tables, fields, conds and order are ok */

271
  if (setup_tables(tables_list) ||
272
      setup_wild(thd, tables_list, fields_list, &all_fields, wild_num) ||
bell@laptop.sanja.is.com.ua's avatar
bell@laptop.sanja.is.com.ua committed
273
      select_lex->setup_ref_array(thd, og_num) ||
274 275 276 277 278
      setup_fields(thd, (*rref_pointer_array), tables_list, fields_list, 1,
		   &all_fields, 1) ||
      setup_without_group(thd, (*rref_pointer_array), tables_list, fields_list,
			  all_fields, &conds, order, group_list, 
			  &hidden_group_fields))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
279 280
    DBUG_RETURN(-1);				/* purecov: inspected */

281
  ref_pointer_array= *rref_pointer_array;
282
  
bk@work.mysql.com's avatar
bk@work.mysql.com committed
283 284 285 286
  if (having)
  {
    thd->where="having clause";
    thd->allow_sum_func=1;
287
    select_lex->having_fix_field= 1;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
288 289 290
    bool having_fix_rc= (!having->fixed &&
			 (having->fix_fields(thd, tables_list, &having) ||
			  having->check_cols(1)));
291
    select_lex->having_fix_field= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
292
    if (having_fix_rc || thd->net.report_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
293 294
      DBUG_RETURN(-1);				/* purecov: inspected */
  }
295

296 297 298
  // Is it subselect
  {
    Item_subselect *subselect;
299
    if ((subselect= select_lex->master_unit()->item))
300 301
    {
      Item_subselect::trans_res res;
302
      if ((res= subselect->select_transformer(this)) !=
303 304
	  Item_subselect::RES_OK)
	DBUG_RETURN((res == Item_subselect::RES_ERROR));
305 306 307
    }
  }

308 309 310
  if (having && having->with_sum_func)
    having->split_sum_func2(thd, ref_pointer_array, all_fields, &having);

311
  if (setup_ftfuncs(select_lex)) /* should be after having->fix_fields */
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
312
    DBUG_RETURN(-1);
313 314
  

bk@work.mysql.com's avatar
bk@work.mysql.com committed
315 316 317 318 319
  /*
    Check if one one uses a not constant column with group functions
    and no GROUP BY.
    TODO:  Add check of calculation of GROUP functions and fields:
	   SELECT COUNT(*)+table.col1 from table1;
320
  */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
321
  {
322
    if (!group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
323 324
    {
      uint flag=0;
325
      List_iterator_fast<Item> it(fields_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
326 327 328 329 330
      Item *item;
      while ((item= it++))
      {
	if (item->with_sum_func)
	  flag|=1;
331
	else if (!(flag & 2) && !item->const_during_execution())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
332 333 334 335 336 337 338 339
	  flag|=2;
      }
      if (flag == 3)
      {
	my_error(ER_MIX_OF_GROUP_FUNC_AND_FIELDS,MYF(0));
	DBUG_RETURN(-1);
      }
    }
340 341
    TABLE_LIST *table_ptr;
    for (table_ptr= tables_list ; table_ptr ; table_ptr= table_ptr->next)
342
      tables++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
343
  }
344 345 346
  {
    /* Caclulate the number of groups */
    send_group_parts= 0;
347
    for (ORDER *group_tmp= group_list ; group_tmp ; group_tmp= group_tmp->next)
348 349 350
      send_group_parts++;
  }
  
351
  procedure= setup_procedure(thd, proc_param, result, fields_list, &error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
352
  if (error)
353
    goto err;					/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
354 355
  if (procedure)
  {
356 357
    if (setup_new_fields(thd, tables_list, fields_list, all_fields,
			 procedure->param_fields))
358
	goto err;				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
359 360
    if (procedure->group)
    {
361
      if (!test_if_subpart(procedure->group,group_list))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
362 363 364
      {						/* purecov: inspected */
	my_message(0,"Can't handle procedures with differents groups yet",
		   MYF(0));			/* purecov: inspected */
365
	goto err;				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
366 367 368
      }
    }
#ifdef NOT_NEEDED
369
    else if (!group_list && procedure->flags & PROC_GROUP)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
370 371
    {
      my_message(0,"Select must have a group with this procedure",MYF(0));
372
      goto err;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
373 374 375
    }
#endif
    if (order && (procedure->flags & PROC_NO_SORT))
376
    {						/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
377
      my_message(0,"Can't use order with this procedure",MYF(0)); /* purecov: inspected */
378
      goto err;					/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
379 380 381 382
    }
  }

  /* Init join struct */
383
  count_field_types(&tmp_table_param, all_fields, 0);
384
  ref_pointer_array_size= all_fields.elements*sizeof(Item*);
385 386
  this->group= group_list != 0;
  row_limit= ((select_distinct || order || group_list) ? HA_POS_ERROR :
387
	      unit_arg->select_limit_cnt);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
388
  /* select_limit is used to decide if we are likely to scan the whole table */
389
  select_limit= unit_arg->select_limit_cnt;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
390 391
  if (having || (select_options & OPTION_FOUND_ROWS))
    select_limit= HA_POS_ERROR;
392 393
  do_send_rows = (unit_arg->select_limit_cnt) ? 1 : 0;
  unit= unit_arg;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
394 395

#ifdef RESTRICTED_GROUP
396
  if (sum_func_count && !group_list && (func_count || field_count))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
397
  {
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
398
    my_message(ER_WRONG_SUM_SELECT,ER(ER_WRONG_SUM_SELECT),MYF(0));
399
    goto err;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
400 401
  }
#endif
402 403 404 405 406 407 408 409 410 411
  /*
    We must not yet prepare the result table if it is the same as one of the 
    source tables (INSERT SELECT). This is checked in mysql_execute_command()
    and OPTION_BUFFER_RESULT is added to the select_options. A temporary 
    table is then used to hold the result. The preparation may disable 
    indexes on the result table, which may be used during the select, if it
    is the same table (Bug #6034). Do the preparation after the select phase.
  */
  if (! procedure && ! test(select_options & OPTION_BUFFER_RESULT) &&
      result && result->prepare(fields_list, unit_arg))
412 413 414 415 416 417 418
    goto err;					/* purecov: inspected */

  if (select_lex->olap == ROLLUP_TYPE && rollup_init())
    goto err;
  if (alloc_func_list())
    goto err;

419
  DBUG_RETURN(0); // All OK
420 421 422 423 424

err:
  delete procedure;				/* purecov: inspected */
  procedure= 0;
  DBUG_RETURN(-1);				/* purecov: inspected */
425
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
426

427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442
/*
  test if it is known for optimisation IN subquery

  SYNOPSYS
    JOIN::test_in_subselect
    where - pointer for variable in which conditions should be
            stored if subquery is known

  RETURN
    1 - known
    0 - unknown
*/

bool JOIN::test_in_subselect(Item **where)
{
  if (conds->type() == Item::FUNC_ITEM &&
443
      ((Item_func *)this->conds)->functype() == Item_func::EQ_FUNC &&
444 445 446 447 448 449 450 451 452 453 454
      ((Item_func *)conds)->arguments()[0]->type() == Item::REF_ITEM &&
      ((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM)
  {
    join_tab->info= "Using index";
    *where= 0;
    return 1;
  }
  if (conds->type() == Item::COND_ITEM &&
      ((class Item_func *)this->conds)->functype() ==
      Item_func::COND_AND_FUNC)
  {
455 456 457 458
    if ((*where= remove_additional_cond(conds)))
      join_tab->info= "Using index; Using where";
    else
      join_tab->info= "Using index";
459 460 461 462 463 464
    return 1;
  }
  return 0;
}


465 466 467
/*
  global select optimisation.
  return 0 - success
468
         1 - error
469 470 471 472 473 474
  error code saved in field 'error'
*/
int
JOIN::optimize()
{
  DBUG_ENTER("JOIN::optimize");
475
  // to prevent double initialization on EXPLAIN
476 477 478
  if (optimized)
    DBUG_RETURN(0);
  optimized= 1;
479

480
  // Ignore errors of execution if option IGNORE present
481
  if (thd->lex->ignore)
482
    thd->lex->current_select->no_error= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
483 484
#ifdef HAVE_REF_TO_FIELDS			// Not done yet
  /* Add HAVING to WHERE if possible */
485
  if (having && !group_list && !sum_func_count)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
486 487 488
  {
    if (!conds)
    {
489 490
      conds= having;
      having= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
491 492 493
    }
    else if ((conds=new Item_cond_and(conds,having)))
    {
494
      conds->fix_fields(thd, tables_list, &conds);
495
      conds->change_ref_to_fields(thd, tables_list);
496
      conds->top_level_item();
497
      having= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
498 499 500 501
    }
  }
#endif

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
502
  conds= optimize_cond(thd, conds, &cond_value);
503
  if (thd->net.report_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
504
  {
serg@serg.mylan's avatar
serg@serg.mylan committed
505
    error= 1;
506
    DBUG_PRINT("error",("Error from optimize_cond"));
507
    DBUG_RETURN(1);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
508
  }
509

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527
  {
    Item::cond_result having_value;
    having= optimize_cond(thd, having, &having_value);
    if (thd->net.report_error)
    {
      error= 1;
      DBUG_PRINT("error",("Error from optimize_cond"));
      DBUG_RETURN(1);
    }

    if (cond_value == Item::COND_FALSE || having_value == Item::COND_FALSE || 
       (!unit->select_limit_cnt && !(select_options & OPTION_FOUND_ROWS)))
    {						/* Impossible cond */
      zero_result_cause= having_value == Item::COND_FALSE ?
                           "Impossible HAVING" : "Impossible WHERE";
      error= 0;
      DBUG_RETURN(0);
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
528 529 530
  }

  /* Optimize count(*), min() and max() */
531
  if (tables_list && tmp_table_param.sum_func_count && ! group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
532 533
  {
    int res;
534
    /*
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
535 536 537 538
      opt_sum_query() returns HA_ERR_KEY_NOT_FOUND if no rows match
      to the WHERE conditions,
      or 1 if all items were resolved,
      or 0, or an error number HA_ERR_...
539
    */
540
    if ((res=opt_sum_query(tables_list, all_fields, conds)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
541
    {
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
542 543 544 545 546 547
      if (res == HA_ERR_KEY_NOT_FOUND)
      {
	zero_result_cause= "No matching min/max row";
	error=0;
	DBUG_RETURN(0);
      }
548 549
      if (res > 1)
      {
550 551
        thd->fatal_error();
        error= res;
552
	DBUG_RETURN(1);
553
      }
554
      zero_result_cause= "Select tables optimized away";
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
555
      tables_list= 0;				// All tables resolved
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
      /*
        Extract all table-independent conditions and replace the WHERE
        clause with them. All other conditions were computed by opt_sum_query
        and the MIN/MAX/COUNT function(s) have been replaced by constants,
        so there is no need to compute the whole WHERE clause again.
        Notice that make_cond_for_table() will always succeed to remove all
        computed conditions, because opt_sum_query() is applicable only to
        conjunctions.
      */
      if (conds)
      {
        COND *table_independent_conds=
          make_cond_for_table(conds, PSEUDO_TABLE_BITS, 0);
        DBUG_EXECUTE("where",
                     print_where(table_independent_conds,
                                 "where after opt_sum_query()"););
        conds= table_independent_conds;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
574 575
    }
  }
576
  if (!tables_list)
577 578
  {
    error= 0;
579
    DBUG_RETURN(0);
580
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
581
  error= -1;					// Error is sent to client
582
  sort_by_table= get_sort_by_table(order, group_list, tables_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
583 584

  /* Calculate how to do the join */
585 586
  thd->proc_info= "statistics";
  if (make_join_statistics(this, tables_list, conds, &keyuse) ||
587
      thd->is_fatal_error)
588 589
  {
    DBUG_PRINT("error",("Error: make_join_statistics() failed"));
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
590
    DBUG_RETURN(1);
591
  }
592

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
593 594
  /* Remove distinct if only const tables */
  select_distinct= select_distinct && (const_tables != tables);
595
  thd->proc_info= "preparing";
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
596
  if (result->initialize_tables(this))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
597
  {
598 599
    DBUG_PRINT("error",("Error: initialize_tables() failed"));
    DBUG_RETURN(1);				// error == -1
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
600
  }
601
  if (const_table_map != found_const_table_map &&
602
      !(select_options & SELECT_DESCRIBE) &&
603 604 605
      (!conds ||
       !(conds->used_tables() & RAND_TABLE_BIT) ||
       select_lex->master_unit() == &thd->lex->unit)) // upper level SELECT
bk@work.mysql.com's avatar
bk@work.mysql.com committed
606
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
607
    zero_result_cause= "no matching row in const table";
608 609
    DBUG_PRINT("error",("Error: %s", zero_result_cause));
    error= 0;
610
    DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
611 612
  }
  if (!(thd->options & OPTION_BIG_SELECTS) &&
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
613
      best_read > (double) thd->variables.max_join_size &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
614 615
      !(select_options & SELECT_DESCRIBE))
  {						/* purecov: inspected */
616
    my_message(ER_TOO_BIG_SELECT, ER(ER_TOO_BIG_SELECT), MYF(0));
617
    error= -1;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
618
    DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
619
  }
620
  if (const_tables && !thd->locked_tables &&
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
621
      !(select_options & SELECT_NO_UNLOCK))
622
    mysql_unlock_some_tables(thd, table, const_tables);
623

624
  if (!conds && outer_join)
625 626 627 628
  {
    /* Handle the case where we have an OUTER JOIN without a WHERE */
    conds=new Item_int((longlong) 1,1);	// Always true
  }
629 630
  select=make_select(*table, const_table_map,
		     const_table_map, conds, &error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
631
  if (error)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
632 633
  {						/* purecov: inspected */
    error= -1;					/* purecov: inspected */
634
    DBUG_PRINT("error",("Error: make_select() failed"));
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
635
    DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
636
  }
637 638 639 640 641 642
  if (conds &&!outer_join && const_table_map != found_const_table_map && 
      (select_options & SELECT_DESCRIBE) &&
      select_lex->master_unit() == &thd->lex->unit) // upper level SELECT
  {
    conds=new Item_int((longlong) 0,1);	// Always false
  }
643
  if (make_join_select(this, select, conds))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
644
  {
645 646
    zero_result_cause=
      "Impossible WHERE noticed after reading const tables";
647
    DBUG_RETURN(0);				// error == 0
bk@work.mysql.com's avatar
bk@work.mysql.com committed
648 649 650 651 652
  }

  error= -1;					/* if goto err */

  /* Optimize distinct away if possible */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
653 654
  {
    ORDER *org_order= order;
655
    order=remove_const(this, order,conds,1, &simple_order);
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
656 657 658 659 660 661 662
    if (thd->net.report_error)
    {
      error= 1;
      DBUG_PRINT("error",("Error from remove_const"));
      DBUG_RETURN(1);
    }

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
663 664 665 666 667 668 669
    /*
      If we are using ORDER BY NULL or ORDER BY const_expression,
      return result in any order (even if we are using a GROUP BY)
    */
    if (!order && org_order)
      skip_sort_order= 1;
  }
670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
  /*
     Check if we can optimize away GROUP BY/DISTINCT.
     We can do that if there are no aggregate functions and the
     fields in DISTINCT clause (if present) and/or columns in GROUP BY
     (if present) contain direct references to all key parts of
     an unique index (in whatever order).
     Note that the unique keys for DISTINCT and GROUP BY should not
     be the same (as long as they are unique).

     The FROM clause must contain a single non-constant table.
  */
  if (tables - const_tables == 1 && (group_list || select_distinct) &&
      !tmp_table_param.sum_func_count)
  {
    if (group_list &&
       list_contains_unique_index(join_tab[const_tables].table,
                                 find_field_in_order_list,
                                 (void *) group_list))
    {
      group_list= 0;
      group= 0;
    }
    if (select_distinct &&
       list_contains_unique_index(join_tab[const_tables].table,
                                 find_field_in_item_list,
                                 (void *) &fields_list))
    {
      select_distinct= 0;
    }
  }
700
  if (group_list || tmp_table_param.sum_func_count)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
701
  {
702
    if (! hidden_group_fields && rollup.state == ROLLUP::STATE_NONE)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
703 704
      select_distinct=0;
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
705
  else if (select_distinct && tables - const_tables == 1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
706
  {
707 708 709 710 711 712 713 714 715 716 717 718 719 720 721
    /*
      We are only using one table. In this case we change DISTINCT to a
      GROUP BY query if:
      - The GROUP BY can be done through indexes (no sort) and the ORDER
        BY only uses selected fields.
	(In this case we can later optimize away GROUP BY and ORDER BY)
      - We are scanning the whole table without LIMIT
        This can happen if:
        - We are using CALC_FOUND_ROWS
        - We are using an ORDER BY that can't be optimized away.

      We don't want to use this optimization when we are using LIMIT
      because in this case we can just create a temporary table that
      holds LIMIT rows and stop when this table is full.
    */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
722
    JOIN_TAB *tab= &join_tab[const_tables];
723 724 725
    bool all_order_fields_used;
    if (order)
      skip_sort_order= test_if_skip_sort_order(tab, order, select_limit, 1);
726 727
    if ((group_list=create_distinct_group(thd, select_lex->ref_pointer_array,
                                          order, fields_list,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
728
				          &all_order_fields_used)))
729 730
    {
      bool skip_group= (skip_sort_order &&
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
731
			test_if_skip_sort_order(tab, group_list, select_limit,
732 733 734 735 736 737 738 739 740
						1) != 0);
      if ((skip_group && all_order_fields_used) ||
	  select_limit == HA_POS_ERROR ||
	  (order && !skip_sort_order))
      {
	/*  Change DISTINCT to GROUP BY */
	select_distinct= 0;
	no_order= !order;
	if (all_order_fields_used)
741 742 743 744 745 746
	{
	  if (order && skip_sort_order)
	  {
	    /*
	      Force MySQL to read the table in sorted order to get result in
	      ORDER BY order.
serg@serg.mylan's avatar
serg@serg.mylan committed
747
	    */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
748
	    tmp_table_param.quick_group=0;
749
	  }
750
	  order=0;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
751
        }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
752
	group=1;				// For end_write_group
753 754
      }
      else
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
755
	group_list= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
756
    }
757
    else if (thd->is_fatal_error)			// End of memory
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
758
      DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
759
  }
760
  simple_group= 0;
761 762 763 764 765
  {
    ORDER *old_group_list;
    group_list= remove_const(this, (old_group_list= group_list), conds,
                             rollup.state == ROLLUP::STATE_NONE,
			     &simple_group);
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
766 767 768 769 770 771
    if (thd->net.report_error)
    {
      error= 1;
      DBUG_PRINT("error",("Error from remove_const"));
      DBUG_RETURN(1);
    }
772 773 774
    if (old_group_list && !group_list)
      select_distinct= 0;
  }
775
  if (!group_list && group)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
776 777 778
  {
    order=0;					// The output has only one row
    simple_order=1;
779
    select_distinct= 0;                       // No need in distinct for 1 row
780
    group_optimized_away= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
781 782
  }

783 784
  calc_group_buffer(this, group_list);
  send_group_parts= tmp_table_param.group_parts; /* Save org parts */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
785 786
  if (procedure && procedure->group)
  {
787
    group_list= procedure->group= remove_const(this, procedure->group, conds,
788
					       1, &simple_group);
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
789 790 791 792 793 794
    if (thd->net.report_error)
    {
      error= 1;
      DBUG_PRINT("error",("Error from remove_const"));
      DBUG_RETURN(1);
    }   
795
    calc_group_buffer(this, group_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
796 797
  }

798 799
  if (test_if_subpart(group_list, order) ||
      (!group_list && tmp_table_param.sum_func_count))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
800 801
    order=0;

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
802
  // Can't use sort on head table if using row cache
803
  if (full_join)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
804
  {
805
    if (group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
806 807 808 809 810
      simple_group=0;
    if (order)
      simple_order=0;
  }

811 812 813 814 815 816 817 818 819
  /*
    Check if we need to create a temporary table.
    This has to be done if all tables are not already read (const tables)
    and one of the following conditions holds:
    - We are using DISTINCT (simple distinct's are already optimized away)
    - We are using an ORDER BY or GROUP BY on fields not in the first table
    - We are using different ORDER BY and GROUP BY orders
    - The user wants us to buffer the result.
  */
820
  need_tmp= (const_tables != tables &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
821
	     ((select_distinct || !simple_order || !simple_group) ||
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
822
	      (group_list && order) ||
823
	      test(select_options & OPTION_BUFFER_RESULT)));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
824

825
  // No cache for MATCH
826
  make_join_readinfo(this,
827
		     (select_options & (SELECT_DESCRIBE |
828
					SELECT_NO_JOIN_CACHE)) |
serg@serg.mylan's avatar
serg@serg.mylan committed
829
		     (select_lex->ftfunc_list->elements ?
830
		      SELECT_NO_JOIN_CACHE : 0));
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
831

832 833 834 835
  /* Perform FULLTEXT search before all regular searches */
  if (!(select_options & SELECT_DESCRIBE))
    init_ftfuncs(thd, select_lex, test(order));

836 837 838
  /*
    is this simple IN subquery?
  */
839
  if (!group_list && !order &&
840
      unit->item && unit->item->substype() == Item_subselect::IN_SUBS &&
841
      tables == 1 && conds &&
842 843
      !unit->first_select()->next_select())
  {
844
    if (!having)
845
    {
846
      Item *where= 0;
847 848
      if (join_tab[0].type == JT_EQ_REF &&
	  join_tab[0].ref.items[0]->name == in_left_expr_name)
849
      {
850 851
	if (test_in_subselect(&where))
	{
852
	  join_tab[0].type= JT_UNIQUE_SUBQUERY;
853 854
	  error= 0;
	  DBUG_RETURN(unit->item->
855 856 857 858 859
		      change_engine(new
				    subselect_uniquesubquery_engine(thd,
								    join_tab,
								    unit->item,
								    where)));
860
	}
861
      }
862 863
      else if (join_tab[0].type == JT_REF &&
	       join_tab[0].ref.items[0]->name == in_left_expr_name)
864
      {
865 866
	if (test_in_subselect(&where))
	{
867
	  join_tab[0].type= JT_INDEX_SUBQUERY;
868 869
	  error= 0;
	  DBUG_RETURN(unit->item->
870 871 872 873 874 875
		      change_engine(new
				    subselect_indexsubquery_engine(thd,
								   join_tab,
								   unit->item,
								   where,
								   0)));
876
	}
877
      }
878
    } else if (join_tab[0].type == JT_REF_OR_NULL &&
879
	       join_tab[0].ref.items[0]->name == in_left_expr_name &&
880 881 882 883
	       having->type() == Item::FUNC_ITEM &&
	       ((Item_func *) having)->functype() ==
	       Item_func::ISNOTNULLTEST_FUNC)
    {
884
      join_tab[0].type= JT_INDEX_SUBQUERY;
885
      error= 0;
886 887 888 889 890

      if ((conds= remove_additional_cond(conds)))
	join_tab->info= "Using index; Using where";
      else
	join_tab->info= "Using index";
891

892
      DBUG_RETURN(unit->item->
893 894 895 896 897
		  change_engine(new subselect_indexsubquery_engine(thd,
								   join_tab,
								   unit->item,
								   conds,
								   1)));
898
    }
899

900
  }
901 902 903 904 905 906 907
  /*
    Need to tell Innobase that to play it safe, it should fetch all
    columns of the tables: this is because MySQL may build row
    pointers for the rows, and for all columns of the primary key the
    field->query_id has not necessarily been set to thd->query_id by
    MySQL.
  */
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
908 909

#ifdef HAVE_INNOBASE_DB
910
  if (need_tmp || select_distinct || group_list || order)
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
911
  {
912
    for (uint i_h = const_tables; i_h < tables; i_h++)
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
913
    {
914
      TABLE* table_h = join_tab[i_h].table;
heikki@hundin.mysql.fi's avatar
heikki@hundin.mysql.fi committed
915
      table_h->file->extra(HA_EXTRA_RETRIEVE_PRIMARY_KEY);
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
916 917 918 919
    }
  }
#endif

920
  DBUG_EXECUTE("info",TEST_join(this););
bk@work.mysql.com's avatar
bk@work.mysql.com committed
921 922 923 924 925
  /*
    Because filesort always does a full table scan or a quick range scan
    we must add the removed reference to the select for the table.
    We only need to do this when we have a simple_order or simple_group
    as in other cases the join is done before the sort.
926
  */
927
  if (const_tables != tables &&
928
      (order || group_list) &&
929
      join_tab[const_tables].type != JT_ALL &&
930
      join_tab[const_tables].type != JT_FT &&
931
      join_tab[const_tables].type != JT_REF_OR_NULL &&
932
      (order && simple_order || group_list && simple_group))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
933
  {
934
    if (add_ref_to_table_cond(thd,&join_tab[const_tables]))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
935
      DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
936 937 938
  }

  if (!(select_options & SELECT_BIG_RESULT) &&
939
      ((group_list && const_tables != tables &&
940
	(!simple_group ||
941
	 !test_if_skip_sort_order(&join_tab[const_tables], group_list,
monty@mysql.com's avatar
monty@mysql.com committed
942 943
				  unit->select_limit_cnt, 0))) ||
       select_distinct) &&
944
      tmp_table_param.quick_group && !procedure)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
945 946 947
  {
    need_tmp=1; simple_order=simple_group=0;	// Force tmp table without sort
  }
948

949
  tmp_having= having;
950
  if (select_options & SELECT_DESCRIBE)
951 952
  {
    error= 0;
953
    DBUG_RETURN(0);
954
  }
955 956 957 958 959 960 961 962 963
  having= 0;

  /* Create a tmp table if distinct or if the sort is too complicated */
  if (need_tmp)
  {
    DBUG_PRINT("info",("Creating tmp table"));
    thd->proc_info="Creating tmp table";

    init_items_ref_array();
964

965 966
    tmp_table_param.hidden_field_count= (all_fields.elements -
					 fields_list.elements);
967 968 969 970 971 972 973 974 975 976 977 978 979 980 981
    ORDER *tmp_group= ((!simple_group && !procedure &&
                        !(test_flags & TEST_NO_KEY_GROUP)) ? group_list :
                                                             (ORDER*) 0);
    /*
      Pushing LIMIT to the temporary table creation is not applicable
      when there is ORDER BY or GROUP BY or there is no GROUP BY, but
      there are aggregate functions, because in all these cases we need
      all result rows.
    */
    ha_rows tmp_rows_limit= ((order == 0 || skip_sort_order ||
                              test(select_options & OPTION_BUFFER_RESULT)) &&
                             !tmp_group &&
                             !thd->lex->current_select->with_sum_func) ?
                            select_limit : HA_POS_ERROR;

982 983
    if (!(exec_tmp_table1 =
	  create_tmp_table(thd, &tmp_table_param, all_fields,
984
                           tmp_group,
985 986 987
			   group_list ? 0 : select_distinct,
			   group_list && simple_group,
			   select_options,
988
                           tmp_rows_limit,
989
			   (char *) "")))
990
      DBUG_RETURN(1);
991 992 993 994 995 996 997 998 999 1000 1001

    /*
      We don't have to store rows in temp table that doesn't match HAVING if:
      - we are sorting the table and writing complete group rows to the
        temp table.
      - We are using DISTINCT without resolving the distinct as a GROUP BY
        on all columns.
      
      If having is not handled here, it will be checked before the row
      is sent to the client.
    */    
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1002
    if (tmp_having && 
1003 1004 1005 1006 1007 1008 1009 1010
	(sort_and_group || (exec_tmp_table1->distinct && !group_list)))
      having= tmp_having;

    /* if group or order on first table, sort first */
    if (group_list && simple_group)
    {
      DBUG_PRINT("info",("Sorting for group"));
      thd->proc_info="Sorting for group";
1011
      if (create_sort_index(thd, this, group_list,
1012
			    HA_POS_ERROR, HA_POS_ERROR) ||
1013 1014
	  alloc_group_fields(this, group_list) ||
	  make_sum_func_list(all_fields, fields_list, 1))
1015 1016 1017 1018 1019
	DBUG_RETURN(1);
      group_list=0;
    }
    else
    {
1020
      if (make_sum_func_list(all_fields, fields_list, 0))
1021 1022 1023 1024 1025
	DBUG_RETURN(1);
      if (!group_list && ! exec_tmp_table1->distinct && order && simple_order)
      {
	DBUG_PRINT("info",("Sorting for order"));
	thd->proc_info="Sorting for order";
1026
	if (create_sort_index(thd, this, order,
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
                              HA_POS_ERROR, HA_POS_ERROR))
	  DBUG_RETURN(1);
	order=0;
      }
    }
    
    /*
      Optimize distinct when used on some of the tables
      SELECT DISTINCT t1.a FROM t1,t2 WHERE t1.b=t2.b
      In this case we can stop scanning t2 when we have found one t1.a
    */

    if (exec_tmp_table1->distinct)
    {
      table_map used_tables= thd->used_tables;
1042
      JOIN_TAB *last_join_tab= join_tab+tables-1;
1043 1044
      do
      {
1045
	if (used_tables & last_join_tab->table->map)
1046
	  break;
1047 1048
	last_join_tab->not_used_in_distinct=1;
      } while (last_join_tab-- != join_tab);
1049 1050 1051 1052
      /* Optimize "select distinct b from t1 order by key_part_1 limit #" */
      if (order && skip_sort_order)
      {
 	/* Should always succeed */
1053
	if (test_if_skip_sort_order(&join_tab[const_tables],
1054 1055 1056 1057 1058
				    order, unit->select_limit_cnt, 0))
	  order=0;
      }
    }
    
1059
    if (thd->lex->subqueries)
1060 1061 1062
    {
      if (!(tmp_join= (JOIN*)thd->alloc(sizeof(JOIN))))
	DBUG_RETURN(-1);
1063
      error= 0;				// Ensure that tmp_join.error= 0
1064 1065 1066 1067
      restore_tmp();
    }
  }

1068
  error= 0;
1069 1070 1071
  DBUG_RETURN(0);
}

1072

1073
/*
1074
  Restore values in temporary join
1075
*/
1076
void JOIN::restore_tmp()
1077
{
1078
  memcpy(tmp_join, this, (size_t) sizeof(JOIN));
1079 1080
}

1081

1082 1083 1084 1085
int
JOIN::reinit()
{
  DBUG_ENTER("JOIN::reinit");
1086
  /* TODO move to unit reinit */
1087 1088 1089 1090 1091 1092
  unit->offset_limit_cnt =select_lex->offset_limit;
  unit->select_limit_cnt =select_lex->select_limit+select_lex->offset_limit;
  if (unit->select_limit_cnt < select_lex->select_limit)
    unit->select_limit_cnt= HA_POS_ERROR;		// no limit
  if (unit->select_limit_cnt == HA_POS_ERROR)
    select_lex->options&= ~OPTION_FOUND_ROWS;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1093
  
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
1094
  if (!optimized && setup_tables(tables_list))
1095
    DBUG_RETURN(1);
1096
  
1097
  /* Reset of sum functions */
1098
  first_record= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1099

1100 1101 1102 1103 1104
  if (exec_tmp_table1)
  {
    exec_tmp_table1->file->extra(HA_EXTRA_RESET_STATE);
    exec_tmp_table1->file->delete_all_rows();
    free_io_cache(exec_tmp_table1);
1105
    filesort_free_buffers(exec_tmp_table1);
1106 1107 1108 1109 1110 1111
  }
  if (exec_tmp_table2)
  {
    exec_tmp_table2->file->extra(HA_EXTRA_RESET_STATE);
    exec_tmp_table2->file->delete_all_rows();
    free_io_cache(exec_tmp_table2);
1112
    filesort_free_buffers(exec_tmp_table2);
1113 1114
  }
  if (items0)
1115
    set_items_ref_array(items0);
1116

1117 1118 1119
  if (join_tab_save)
    memcpy(join_tab, join_tab_save, sizeof(JOIN_TAB) * tables);

1120 1121 1122
  if (tmp_join)
    restore_tmp();

1123 1124 1125 1126 1127 1128 1129
  if (sum_funcs)
  {
    Item_sum *func, **func_ptr= sum_funcs;
    while ((func= *(func_ptr++)))
      func->clear();
  }

1130 1131 1132
  DBUG_RETURN(0);
}

1133 1134 1135 1136

bool
JOIN::save_join_tab()
{
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1137
  if (!join_tab_save && select_lex->master_unit()->uncacheable)
1138
  {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1139 1140
    if (!(join_tab_save= (JOIN_TAB*)thd->memdup((gptr) join_tab,
						sizeof(JOIN_TAB) * tables)))
1141 1142 1143 1144 1145 1146
      return 1;
  }
  return 0;
}


1147
/*
1148
  Exec select
1149 1150 1151 1152
*/
void
JOIN::exec()
{
1153
  List<Item> *columns_list= &fields_list;
1154 1155
  int      tmp_error;
  DBUG_ENTER("JOIN::exec");
1156
  
1157
  error= 0;
1158 1159
  if (procedure)
  {
1160 1161 1162
    procedure_fields_list= fields_list;
    if (procedure->change_columns(procedure_fields_list) ||
	result->prepare(procedure_fields_list, unit))
1163 1164
    {
      thd->limit_found_rows= thd->examined_row_count= 0;
1165
      DBUG_VOID_RETURN;
1166
    }
1167
    columns_list= &procedure_fields_list;
1168
  }
1169 1170 1171 1172 1173 1174 1175
  else if (test(select_options & OPTION_BUFFER_RESULT) &&
           result && result->prepare(fields_list, unit))
  {
    error= 1;
    thd->limit_found_rows= thd->examined_row_count= 0;
    DBUG_VOID_RETURN;
  }
1176

1177
  if (!tables_list && (tables || !select_lex->with_sum_func))
1178 1179
  {                                           // Only test of functions
    if (select_options & SELECT_DESCRIBE)
monty@mysql.com's avatar
monty@mysql.com committed
1180
      select_describe(this, FALSE, FALSE, FALSE,
1181
		      (zero_result_cause?zero_result_cause:"No tables used"));
1182 1183
    else
    {
1184
      result->send_fields(*columns_list, 1);
1185 1186 1187 1188 1189 1190 1191 1192
      /*
        We have to test for 'conds' here as the WHERE may not be constant
        even if we don't have any tables for prepared statements or if
        conds uses something like 'rand()'.
      */
      if (cond_value != Item::COND_FALSE &&
          (!conds || conds->val_int()) &&
          (!having || having->val_int()))
1193
      {
1194 1195 1196
	if (do_send_rows &&
            (procedure ? (procedure->send_row(procedure_fields_list) ||
             procedure->end_of_records()) : result->send_data(fields_list)))
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1197
	  error= 1;
1198
	else
1199
	{
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1200
	  error= (int) result->send_eof();
1201 1202
	  send_records= ((select_options & OPTION_FOUND_ROWS) ? 1 :
                         thd->sent_row_count);
1203
	}
1204 1205
      }
      else
1206
      {
1207
	error=(int) result->send_eof();
1208 1209
        send_records= 0;
      }
1210
    }
1211 1212
    /* Single select (without union) always returns 0 or 1 row */
    thd->limit_found_rows= send_records;
1213
    thd->examined_row_count= 0;
1214 1215
    DBUG_VOID_RETURN;
  }
1216 1217 1218 1219 1220
  /*
    Don't reset the found rows count if there're no tables as
    FOUND_ROWS() may be called. Never reset the examined row count here.
    It must be accumulated from all join iterations of all join parts.
  */
1221
  if (tables)
1222
    thd->limit_found_rows= 0;
1223 1224 1225

  if (zero_result_cause)
  {
1226
    (void) return_zero_rows(this, result, tables_list, *columns_list,
1227
			    send_row_on_empty_set(),
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1228 1229
			    select_options,
			    zero_result_cause,
1230
			    having, procedure,
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1231
			    unit);
1232 1233 1234
    DBUG_VOID_RETURN;
  }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1235 1236
  if (select_options & SELECT_DESCRIBE)
  {
monty@mysql.com's avatar
monty@mysql.com committed
1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251
    /*
      Check if we managed to optimize ORDER BY away and don't use temporary
      table to resolve ORDER BY: in that case, we only may need to do
      filesort for GROUP BY.
    */
    if (!order && !no_order && (!skip_sort_order || !need_tmp))
    {
      /*
	Reset 'order' to 'group_list' and reinit variables describing
	'order'
      */
      order= group_list;
      simple_order= simple_group;
      skip_sort_order= 0;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1252
    if (order &&
1253
	(const_tables == tables ||
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1254
 	 ((simple_order || skip_sort_order) &&
1255
	  test_if_skip_sort_order(&join_tab[const_tables], order,
1256
				  select_limit, 0))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1257
      order=0;
1258
    having= tmp_having;
1259
    select_describe(this, need_tmp,
1260
		    order != 0 && !skip_sort_order,
1261 1262
		    select_distinct,
                    !tables ? "No tables used" : NullS);
1263
    DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1264 1265
  }

1266 1267 1268 1269
  JOIN *curr_join= this;
  List<Item> *curr_all_fields= &all_fields;
  List<Item> *curr_fields_list= &fields_list;
  TABLE *curr_tmp_table= 0;
1270 1271 1272 1273 1274 1275
  /*
    Initialize examined rows here because the values from all join parts
    must be accumulated in examined_row_count. Hence every join
    iteration must count from zero.
  */
  curr_join->examined_rows= 0;
1276

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1277 1278 1279
  /* Create a tmp table if distinct or if the sort is too complicated */
  if (need_tmp)
  {
1280 1281 1282
    if (tmp_join)
      curr_join= tmp_join;
    curr_tmp_table= exec_tmp_table1;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
1283 1284

    /* Copy data to the temporary table */
1285
    thd->proc_info= "Copying to tmp table";
1286 1287
    
    if ((tmp_error= do_select(curr_join, (List<Item> *) 0, curr_tmp_table, 0)))
1288
    {
1289 1290
      error= tmp_error;
      DBUG_VOID_RETURN;
1291
    }
1292 1293 1294 1295 1296
    curr_tmp_table->file->info(HA_STATUS_VARIABLE);
    
    if (curr_join->having)
      curr_join->having= curr_join->tmp_having= 0; // Allready done
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1297
    /* Change sum_fields reference to calculated fields in tmp_table */
1298 1299
    curr_join->all_fields= *curr_all_fields;
    if (!items1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1300
    {
1301 1302 1303
      items1= items0 + all_fields.elements;
      if (sort_and_group || curr_tmp_table->group)
      {
1304
	if (change_to_use_tmp_fields(thd, items1,
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321
				     tmp_fields_list1, tmp_all_fields1,
				     fields_list.elements, all_fields))
	  DBUG_VOID_RETURN;
      }
      else
      {
	if (change_refs_to_tmp_fields(thd, items1,
				      tmp_fields_list1, tmp_all_fields1,
				      fields_list.elements, all_fields))
	  DBUG_VOID_RETURN;
      }
      curr_join->tmp_all_fields1= tmp_all_fields1;
      curr_join->tmp_fields_list1= tmp_fields_list1;
      curr_join->items1= items1;
    }
    curr_all_fields= &tmp_all_fields1;
    curr_fields_list= &tmp_fields_list1;
1322
    curr_join->set_items_ref_array(items1);
1323 1324 1325 1326 1327 1328 1329 1330
    
    if (sort_and_group || curr_tmp_table->group)
    {
      curr_join->tmp_table_param.field_count+= 
	curr_join->tmp_table_param.sum_func_count+
	curr_join->tmp_table_param.func_count;
      curr_join->tmp_table_param.sum_func_count= 
	curr_join->tmp_table_param.func_count= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1331 1332 1333
    }
    else
    {
1334 1335 1336
      curr_join->tmp_table_param.field_count+= 
	curr_join->tmp_table_param.func_count;
      curr_join->tmp_table_param.func_count= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1337
    }
1338 1339
    
    // procedure can't be used inside subselect => we do nothing special for it
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1340 1341
    if (procedure)
      procedure->update_refs();
1342 1343
    
    if (curr_tmp_table->group)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1344
    {						// Already grouped
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1345
      if (!curr_join->order && !curr_join->no_order && !skip_sort_order)
1346 1347
	curr_join->order= curr_join->group_list;  /* order by group */
      curr_join->group_list= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1348
    }
1349
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1350
    /*
1351 1352 1353 1354 1355
      If we have different sort & group then we must sort the data by group
      and copy it to another tmp table
      This code is also used if we are using distinct something
      we haven't been able to store in the temporary table yet
      like SEC_TO_TIME(SUM(...)).
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1356 1357
    */

1358 1359 1360 1361 1362
    if (curr_join->group_list && (!test_if_subpart(curr_join->group_list,
						   curr_join->order) || 
				  curr_join->select_distinct) ||
	(curr_join->select_distinct &&
	 curr_join->tmp_table_param.using_indirect_summary_function))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1363 1364
    {					/* Must copy to another table */
      DBUG_PRINT("info",("Creating group table"));
1365
      
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1366
      /* Free first data from old join */
1367
      curr_join->join_free(0);
1368
      if (make_simple_join(curr_join, curr_tmp_table))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1369
	DBUG_VOID_RETURN;
1370
      calc_group_buffer(curr_join, group_list);
1371 1372
      count_field_types(&curr_join->tmp_table_param,
			curr_join->tmp_all_fields1,
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
			curr_join->select_distinct && !curr_join->group_list);
      curr_join->tmp_table_param.hidden_field_count= 
	(curr_join->tmp_all_fields1.elements-
	 curr_join->tmp_fields_list1.elements);
      
      
      if (exec_tmp_table2)
	curr_tmp_table= exec_tmp_table2;
      else
      {
	/* group data to new table */
	if (!(curr_tmp_table=
	      exec_tmp_table2= create_tmp_table(thd,
						&curr_join->tmp_table_param,
						*curr_all_fields,
						(ORDER*) 0,
						curr_join->select_distinct && 
						!curr_join->group_list,
						1, curr_join->select_options,
1392 1393
						HA_POS_ERROR,
						(char *) "")))
1394 1395 1396
	  DBUG_VOID_RETURN;
	curr_join->exec_tmp_table2= exec_tmp_table2;
      }
1397
      if (curr_join->group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1398
      {
1399
	thd->proc_info= "Creating sort index";
1400 1401 1402 1403
	if (curr_join->join_tab == join_tab && save_join_tab())
	{
	  DBUG_VOID_RETURN;
	}
1404
	if (create_sort_index(thd, curr_join, curr_join->group_list,
1405
			      HA_POS_ERROR, HA_POS_ERROR) ||
1406
	    make_group_fields(this, curr_join))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1407
	{
1408
	  DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1409 1410
	}
      }
1411
      
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1412
      thd->proc_info="Copying to group table";
1413
      tmp_error= -1;
1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427
      if (curr_join != this)
      {
	if (sum_funcs2)
	{
	  curr_join->sum_funcs= sum_funcs2;
	  curr_join->sum_funcs_end= sum_funcs_end2; 
	}
	else
	{
	  curr_join->alloc_func_list();
	  sum_funcs2= curr_join->sum_funcs;
	  sum_funcs_end2= curr_join->sum_funcs_end;
	}
      }
1428
      if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
1429 1430 1431 1432
					1))
        DBUG_VOID_RETURN;
      curr_join->group_list= 0;
      if ((tmp_error= do_select(curr_join, (List<Item> *) 0, curr_tmp_table,
1433
				0)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1434
      {
1435
	error= tmp_error;
1436
	DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1437
      }
1438 1439 1440 1441 1442 1443 1444 1445
      end_read_record(&curr_join->join_tab->read_record);
      curr_join->const_tables= curr_join->tables; // Mark free for join_free()
      curr_join->join_tab[0].table= 0;           // Table is freed
      
      // No sum funcs anymore
      if (!items2)
      {
	items2= items1 + all_fields.elements;
1446
	if (change_to_use_tmp_fields(thd, items2,
1447 1448 1449 1450 1451 1452 1453 1454
				     tmp_fields_list2, tmp_all_fields2, 
				     fields_list.elements, tmp_all_fields1))
	  DBUG_VOID_RETURN;
	curr_join->tmp_fields_list2= tmp_fields_list2;
	curr_join->tmp_all_fields2= tmp_all_fields2;
      }
      curr_fields_list= &curr_join->tmp_fields_list2;
      curr_all_fields= &curr_join->tmp_all_fields2;
1455
      curr_join->set_items_ref_array(items2);
1456 1457 1458 1459 1460 1461 1462
      curr_join->tmp_table_param.field_count+= 
	curr_join->tmp_table_param.sum_func_count;
      curr_join->tmp_table_param.sum_func_count= 0;
    }
    if (curr_tmp_table->distinct)
      curr_join->select_distinct=0;		/* Each row is unique */
    
1463
    curr_join->join_free(0);			/* Free quick selects */
1464
    if (curr_join->select_distinct && ! curr_join->group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1465 1466
    {
      thd->proc_info="Removing duplicates";
1467 1468 1469
      if (curr_join->tmp_having)
	curr_join->tmp_having->update_used_tables();
      if (remove_duplicates(curr_join, curr_tmp_table,
1470
			    *curr_fields_list, curr_join->tmp_having))
1471
	DBUG_VOID_RETURN;
1472 1473
      curr_join->tmp_having=0;
      curr_join->select_distinct=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1474
    }
1475 1476
    curr_tmp_table->reginfo.lock_type= TL_UNLOCK;
    if (make_simple_join(curr_join, curr_tmp_table))
1477
      DBUG_VOID_RETURN;
1478 1479 1480
    calc_group_buffer(curr_join, curr_join->group_list);
    count_field_types(&curr_join->tmp_table_param, *curr_all_fields, 0);
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1481 1482
  }
  if (procedure)
1483 1484 1485
    count_field_types(&curr_join->tmp_table_param, *curr_all_fields, 0);
  
  if (curr_join->group || curr_join->tmp_table_param.sum_func_count ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1486 1487
      (procedure && (procedure->flags & PROC_GROUP)))
  {
1488 1489 1490 1491
    if (make_group_fields(this, curr_join))
    {
      DBUG_VOID_RETURN;
    }
1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
    if (!items3)
    {
      if (!items0)
	init_items_ref_array();
      items3= ref_pointer_array + (all_fields.elements*4);
      setup_copy_fields(thd, &curr_join->tmp_table_param,
			items3, tmp_fields_list3, tmp_all_fields3,
			curr_fields_list->elements, *curr_all_fields);
      tmp_table_param.save_copy_funcs= curr_join->tmp_table_param.copy_funcs;
      tmp_table_param.save_copy_field= curr_join->tmp_table_param.copy_field;
      tmp_table_param.save_copy_field_end=
	curr_join->tmp_table_param.copy_field_end;
      curr_join->tmp_all_fields3= tmp_all_fields3;
      curr_join->tmp_fields_list3= tmp_fields_list3;
    }
    else
    {
      curr_join->tmp_table_param.copy_funcs= tmp_table_param.save_copy_funcs;
      curr_join->tmp_table_param.copy_field= tmp_table_param.save_copy_field;
      curr_join->tmp_table_param.copy_field_end=
	tmp_table_param.save_copy_field_end;
    }
    curr_fields_list= &tmp_fields_list3;
    curr_all_fields= &tmp_all_fields3;
1516
    curr_join->set_items_ref_array(items3);
1517

1518 1519
    if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
				      1) || thd->is_fatal_error)
1520
      DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1521
  }
1522
  if (curr_join->group_list || curr_join->order)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1523 1524 1525 1526
  {
    DBUG_PRINT("info",("Sorting for send_fields"));
    thd->proc_info="Sorting result";
    /* If we have already done the group, add HAVING to sorted table */
1527 1528
    if (curr_join->tmp_having && ! curr_join->group_list && 
	! curr_join->sort_and_group)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1529
    {
1530 1531
      // Some tables may have been const
      curr_join->tmp_having->update_used_tables();
1532 1533 1534
      JOIN_TAB *curr_table= &curr_join->join_tab[curr_join->const_tables];
      table_map used_tables= (curr_join->const_table_map |
			      curr_table->table->map);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1535

1536 1537
      Item* sort_table_cond= make_cond_for_table(curr_join->tmp_having,
						 used_tables,
1538
						 used_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1539 1540
      if (sort_table_cond)
      {
1541 1542
	if (!curr_table->select)
	  if (!(curr_table->select= new SQL_SELECT))
1543
	    DBUG_VOID_RETURN;
1544 1545
	if (!curr_table->select->cond)
	  curr_table->select->cond= sort_table_cond;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1546
	else					// This should never happen
1547
	{
1548
	  if (!(curr_table->select->cond=
1549
		new Item_cond_and(curr_table->select->cond,
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1550
				  sort_table_cond)))
1551
	    DBUG_VOID_RETURN;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1552 1553 1554 1555 1556
	  /*
	    Item_cond_and do not need fix_fields for execution, its parameters
	    are fixed or do not need fix_fields, too
	  */
	  curr_table->select->cond->quick_fix_field();
1557
	}
1558
	curr_table->select_cond= curr_table->select->cond;
1559 1560
	curr_table->select_cond->top_level_item();
	DBUG_EXECUTE("where",print_where(curr_table->select->cond,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1561
					 "select and having"););
1562 1563 1564
	curr_join->tmp_having= make_cond_for_table(curr_join->tmp_having,
						   ~ (table_map) 0,
						   ~used_tables);
1565 1566
	DBUG_EXECUTE("where",print_where(curr_join->tmp_having,
                                         "having after sort"););
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1567 1568
      }
    }
1569
    {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1570
      if (group)
1571
	curr_join->select_limit= HA_POS_ERROR;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1572
      else
1573
      {
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1574 1575 1576 1577
	/*
	  We can abort sorting after thd->select_limit rows if we there is no
	  WHERE clause for any tables after the sorted one.
	*/
1578
	JOIN_TAB *curr_table= &curr_join->join_tab[curr_join->const_tables+1];
1579
	JOIN_TAB *end_table= &curr_join->join_tab[curr_join->tables];
1580
	for (; curr_table < end_table ; curr_table++)
1581
	{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1582 1583 1584 1585 1586 1587
	  /*
	    table->keyuse is set in the case there was an original WHERE clause
	    on the table that was optimized away.
	    table->on_expr tells us that it was a LEFT JOIN and there will be
	    at least one row generated from the table.
	  */
1588 1589
	  if (curr_table->select_cond ||
	      (curr_table->keyuse && !curr_table->on_expr))
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1590 1591
	  {
	    /* We have to sort all rows */
1592
	    curr_join->select_limit= HA_POS_ERROR;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1593 1594
	    break;
	  }
1595 1596
	}
      }
1597 1598 1599 1600
      if (curr_join->join_tab == join_tab && save_join_tab())
      {
	DBUG_VOID_RETURN;
      }
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1601 1602 1603 1604 1605 1606 1607 1608 1609
      /*
	Here we sort rows for ORDER BY/GROUP BY clause, if the optimiser
	chose FILESORT to be faster than INDEX SCAN or there is no 
	suitable index present.
	Note, that create_sort_index calls test_if_skip_sort_order and may
	finally replace sorting with index scan if there is a LIMIT clause in
	the query. XXX: it's never shown in EXPLAIN!
	OPTION_FOUND_ROWS supersedes LIMIT and is taken into account.
      */
1610
      if (create_sort_index(thd, curr_join,
1611 1612
			    curr_join->group_list ? 
			    curr_join->group_list : curr_join->order,
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1613 1614 1615
			    curr_join->select_limit,
			    (select_options & OPTION_FOUND_ROWS ?
			     HA_POS_ERROR : unit->select_limit_cnt)))
1616
	DBUG_VOID_RETURN;
1617
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1618
  }
1619
  curr_join->having= curr_join->tmp_having;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1620
  thd->proc_info="Sending data";
1621
  error= thd->net.report_error ? -1 :
1622
    do_select(curr_join, curr_fields_list, NULL, procedure);
Sinisa@sinisa.nasamreza.org's avatar
Sinisa@sinisa.nasamreza.org committed
1623
  thd->limit_found_rows= curr_join->send_records;
1624 1625 1626 1627
  /* Accumulate the counts from all join iterations of all join parts. */
  thd->examined_row_count+= curr_join->examined_rows;
  DBUG_PRINT("counts", ("thd->examined_row_count: %lu",
                        (ulong) thd->examined_row_count));
1628 1629
  DBUG_VOID_RETURN;
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1630

1631

1632 1633 1634 1635 1636
/*
  Clean up join. Return error that hold JOIN.
*/

int
1637
JOIN::cleanup()
1638
{
1639
  DBUG_ENTER("JOIN::cleanup");
1640 1641 1642
  select_lex->join= 0;

  if (tmp_join)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1643 1644 1645 1646 1647 1648
  {
    if (join_tab != tmp_join->join_tab)
    {
      JOIN_TAB *tab, *end;
      for (tab= join_tab, end= tab+tables ; tab != end ; tab++)
      {
1649
	tab->cleanup();
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1650 1651 1652
      }
    }
    tmp_join->tmp_join= 0;
1653
    tmp_table_param.copy_field=0;
1654
    DBUG_RETURN(tmp_join->cleanup());
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1655
  }
1656

1657
  lock=0;                                     // It's faster to unlock later
1658
  join_free(1);
1659 1660 1661 1662
  if (exec_tmp_table1)
    free_tmp_table(thd, exec_tmp_table1);
  if (exec_tmp_table2)
    free_tmp_table(thd, exec_tmp_table2);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1663 1664 1665
  delete select;
  delete_dynamic(&keyuse);
  delete procedure;
1666 1667 1668
  for (SELECT_LEX_UNIT *lex_unit= select_lex->first_inner_unit();
       lex_unit != 0;
       lex_unit= lex_unit->next_unit())
1669
  {
1670
    error|= lex_unit->cleanup();
1671 1672
  }
  DBUG_RETURN(error);
1673 1674
}

1675

1676
int
1677
mysql_select(THD *thd, Item ***rref_pointer_array,
serg@serg.mylan's avatar
serg@serg.mylan committed
1678
	     TABLE_LIST *tables, uint wild_num, List<Item> &fields,
1679 1680 1681
	     COND *conds, uint og_num,  ORDER *order, ORDER *group,
	     Item *having, ORDER *proc_param, ulong select_options,
	     select_result *result, SELECT_LEX_UNIT *unit,
1682
	     SELECT_LEX *select_lex)
1683
{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1684 1685
  int err;
  bool free_join= 1;
1686 1687
  DBUG_ENTER("mysql_select");

1688
  JOIN *join;
1689
  if (select_lex->join != 0)
1690
  {
1691
    join= select_lex->join;
1692 1693 1694
    // is it single SELECT in derived table, called in derived table creation
    if (select_lex->linkage != DERIVED_TABLE_TYPE ||
	(select_options & SELECT_DESCRIBE))
1695
    {
1696
      if (select_lex->linkage != GLOBAL_OPTIONS_TYPE)
1697
      {
1698
	//here is EXPLAIN of subselect or derived table
1699
	if (join->change_result(result))
1700 1701 1702
	{
	  DBUG_RETURN(-1);
	}
1703
      }
1704
      else
1705
      {
1706 1707 1708 1709 1710 1711
	if (join->prepare(rref_pointer_array, tables, wild_num,
			  conds, og_num, order, group, having, proc_param,
			  select_lex, unit))
	{
	  goto err;
	}
1712
      }
1713
    }
1714
    free_join= 0;
1715
    join->select_options= select_options;
1716
  }
1717 1718
  else
  {
1719 1720
    if (!(join= new JOIN(thd, fields, select_options, result)))
	DBUG_RETURN(-1);
1721 1722
    thd->proc_info="init";
    thd->used_tables=0;                         // Updated by setup_fields
1723 1724
    if (join->prepare(rref_pointer_array, tables, wild_num,
		      conds, og_num, order, group, having, proc_param,
1725
		      select_lex, unit))
1726
    {
1727
      goto err;
1728 1729 1730
    }
  }

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1731
  if ((err= join->optimize()))
1732
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1733 1734
    goto err;					// 1
  }
1735

1736
  if (thd->lex->describe & DESCRIBE_EXTENDED)
1737 1738 1739 1740 1741
  {
    join->conds_history= join->conds;
    join->having_history= (join->having?join->having:join->tmp_having);
  }

1742
  if (thd->net.report_error)
1743 1744 1745 1746
    goto err;

  join->exec();

1747
  if (thd->lex->describe & DESCRIBE_EXTENDED)
1748 1749 1750 1751 1752
  {
    select_lex->where= join->conds_history;
    select_lex->having= join->having_history;
  }

1753
err:
1754 1755 1756
  if (free_join)
  {
    thd->proc_info="end";
1757
    err= join->cleanup();
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1758 1759
    if (thd->net.report_error)
      err= -1;
1760
    delete join;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1761
    DBUG_RETURN(err);
1762
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1763
  DBUG_RETURN(join->error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1764 1765 1766
}

/*****************************************************************************
1767 1768
  Create JOIN_TABS, make a guess about the table types,
  Approximate how many records will be used in each table
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1769 1770
*****************************************************************************/

1771 1772
static ha_rows get_quick_record_count(THD *thd, SQL_SELECT *select,
				      TABLE *table,
serg@serg.mylan's avatar
serg@serg.mylan committed
1773
				      const key_map *keys,ha_rows limit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1774 1775 1776 1777 1778 1779 1780
{
  int error;
  DBUG_ENTER("get_quick_record_count");
  if (select)
  {
    select->head=table;
    table->reginfo.impossible_range=0;
1781 1782
    if ((error= select->test_quick_select(thd, *(key_map *)keys,(table_map) 0,
                                          limit, 0)) == 1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
      DBUG_RETURN(select->quick->records);
    if (error == -1)
    {
      table->reginfo.impossible_range=1;
      DBUG_RETURN(0);
    }
    DBUG_PRINT("warning",("Couldn't use record count on const keypart"));
  }
  DBUG_RETURN(HA_POS_ERROR);			/* This shouldn't happend */
}


1795 1796 1797 1798 1799 1800 1801
/*
  Calculate the best possible join and initialize the join structure

  RETURN VALUES
  0	ok
  1	Fatal error
*/
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
1802

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1803 1804
static bool
make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
1805
		     DYNAMIC_ARRAY *keyuse_array)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1806 1807
{
  int error;
1808 1809 1810
  uint i,table_count,const_count,key;
  table_map found_const_table_map, all_table_map, found_ref, refs;
  key_map const_ref, eq_part;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1811 1812 1813 1814 1815 1816 1817 1818
  TABLE **table_vector;
  JOIN_TAB *stat,*stat_end,*s,**stat_ref;
  KEYUSE *keyuse,*start_keyuse;
  table_map outer_join=0;
  JOIN_TAB *stat_vector[MAX_TABLES+1];
  DBUG_ENTER("make_join_statistics");

  table_count=join->tables;
1819 1820
  stat=(JOIN_TAB*) join->thd->calloc(sizeof(JOIN_TAB)*table_count);
  stat_ref=(JOIN_TAB**) join->thd->alloc(sizeof(JOIN_TAB*)*MAX_TABLES);
1821
  table_vector=(TABLE**) join->thd->alloc(sizeof(TABLE*)*(table_count*2));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1822 1823 1824 1825 1826 1827
  if (!stat || !stat_ref || !table_vector)
    DBUG_RETURN(1);				// Eom /* purecov: inspected */

  join->best_ref=stat_vector;

  stat_end=stat+table_count;
1828
  found_const_table_map= all_table_map=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1829 1830 1831 1832 1833 1834
  const_count=0;

  for (s=stat,i=0 ; tables ; s++,tables=tables->next,i++)
  {
    TABLE *table;
    stat_vector[i]=s;
1835 1836 1837 1838
    s->keys.init();
    s->const_keys.init();
    s->checked_keys.init();
    s->needed_reg.init();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1839
    table_vector[i]=s->table=table=tables->table;
1840 1841 1842 1843 1844 1845
    error= table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
    if(error)
    {
        table->file->print_error(error, MYF(0));
        DBUG_RETURN(1);
    }
1846
    table->quick_keys.clear_all();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1847 1848 1849 1850
    table->reginfo.join_tab=s;
    table->reginfo.not_exists_optimize=0;
    bzero((char*) table->const_key_parts, sizeof(key_part_map)*table->keys);
    all_table_map|= table->map;
1851
    s->join=join;
1852
    s->info=0;					// For describe
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1853 1854
    if ((s->on_expr=tables->on_expr))
    {
1855
      /* Left join */
1856 1857
      if (!table->file->records)
      {						// Empty table
1858
	s->key_dependent=s->dependent=0;	// Ignore LEFT JOIN depend.
1859 1860 1861
	set_position(join,const_count++,s,(KEYUSE*) 0);
	continue;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1862 1863
      s->key_dependent=s->dependent=
	s->on_expr->used_tables() & ~(table->map);
1864 1865 1866 1867
      if (table->outer_join & JOIN_TYPE_LEFT)
	s->dependent|=stat_vector[i-1]->dependent | table_vector[i-1]->map;
      if (tables->outer_join & JOIN_TYPE_RIGHT)
	s->dependent|=tables->next->table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1868 1869 1870 1871 1872 1873 1874 1875
      outer_join|=table->map;
      continue;
    }
    if (tables->straight)			// We don't have to move this
      s->dependent= table_vector[i-1]->map | stat_vector[i-1]->dependent;
    else
      s->dependent=(table_map) 0;
    s->key_dependent=(table_map) 0;
1876
    if ((table->system || table->file->records <= 1) && ! s->dependent &&
1877
	!(table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
1878
        !table->fulltext_searched)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1879 1880 1881 1882 1883
    {
      set_position(join,const_count++,s,(KEYUSE*) 0);
    }
  }
  stat_vector[i]=0;
1884
  join->outer_join=outer_join;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1885 1886

  /*
1887 1888 1889 1890
    If outer join: Re-arrange tables in stat_vector so that outer join
    tables are after all tables it is dependent of.
    For example: SELECT * from A LEFT JOIN B ON B.c=C.c, C WHERE A.C=C.C
    Will shift table B after table C.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922
  */
  if (outer_join)
  {
    table_map used_tables=0L;
    for (i=0 ; i < join->tables-1 ; i++)
    {
      if (stat_vector[i]->dependent & ~used_tables)
      {
	JOIN_TAB *save= stat_vector[i];
	uint j;
	for (j=i+1;
	     j < join->tables && stat_vector[j]->dependent & ~used_tables;
	     j++)
	{
	  JOIN_TAB *tmp=stat_vector[j];		// Move element up
	  stat_vector[j]=save;
	  save=tmp;
	}
	if (j == join->tables)
	{
	  join->tables=0;			// Don't use join->table
	  my_error(ER_WRONG_OUTER_JOIN,MYF(0));
	  DBUG_RETURN(1);
	}
	stat_vector[i]=stat_vector[j];
	stat_vector[j]=save;
      }
      used_tables|= stat_vector[i]->table->map;
    }
  }

  if (conds || outer_join)
1923 1924
    if (update_ref_and_keys(join->thd, keyuse_array, stat, join->tables,
                            conds, ~outer_join, join->select_lex))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1925 1926
      DBUG_RETURN(1);

1927
  /* Read tables with 0 or 1 rows (system tables) */
1928
  join->const_table_map= 0;
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946

  for (POSITION *p_pos=join->positions, *p_end=p_pos+const_count;
       p_pos < p_end ;
       p_pos++)
  {
    int tmp;
    s= p_pos->table;
    s->type=JT_SYSTEM;
    join->const_table_map|=s->table->map;
    if ((tmp=join_read_const_table(s, p_pos)))
    {
      if (tmp > 0)
	DBUG_RETURN(1);			// Fatal error
    }
    else
      found_const_table_map|= s->table->map;
  }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1947
  /* loop until no more const tables are found */
1948
  int ref_changed;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1949 1950
  do
  {
1951
    ref_changed = 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1952
    found_ref=0;
1953 1954 1955 1956 1957 1958 1959

    /*
      We only have to loop from stat_vector + const_count as
      set_position() will move all const_tables first in stat_vector
    */

    for (JOIN_TAB **pos=stat_vector+const_count ; (s= *pos) ; pos++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1960
    {
1961
      TABLE *table=s->table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1962 1963
      if (s->dependent)				// If dependent on some table
      {
1964
	// All dep. must be constants
1965
	if (s->dependent & ~(found_const_table_map))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1966
	  continue;
1967
	if (table->file->records <= 1L &&
1968
	    !(table->file->table_flags() & HA_NOT_EXACT_COUNT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1969
	{					// system table
1970
	  int tmp= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1971
	  s->type=JT_SYSTEM;
1972
	  join->const_table_map|=table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1973
	  set_position(join,const_count++,s,(KEYUSE*) 0);
1974
	  if ((tmp= join_read_const_table(s,join->positions+const_count-1)))
1975 1976 1977 1978 1979 1980
	  {
	    if (tmp > 0)
	      DBUG_RETURN(1);			// Fatal error
	  }
	  else
	    found_const_table_map|= table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
	  continue;
	}
      }
      /* check if table can be read by key or table only uses const refs */
      if ((keyuse=s->keyuse))
      {
	s->type= JT_REF;
	while (keyuse->table == table)
	{
	  start_keyuse=keyuse;
	  key=keyuse->key;
1992
	  s->keys.set_bit(key);               // QQ: remove this ?
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1993

1994 1995 1996
	  refs=0;
          const_ref.clear_all();
	  eq_part.clear_all();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1997 1998
	  do
	  {
1999
	    if (keyuse->val->type() != Item::NULL_ITEM && !keyuse->optimize)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2000
	    {
2001
	      if (!((~found_const_table_map) & keyuse->used_tables))
2002
		const_ref.set_bit(keyuse->keypart);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2003 2004
	      else
		refs|=keyuse->used_tables;
2005
	      eq_part.set_bit(keyuse->keypart);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2006 2007 2008 2009
	    }
	    keyuse++;
	  } while (keyuse->table == table && keyuse->key == key);

2010
	  if (eq_part.is_prefix(table->key_info[key].key_parts) &&
2011 2012
	      ((table->key_info[key].flags & (HA_NOSAME | HA_END_SPACE_KEY)) ==
	       HA_NOSAME) &&
2013
              !table->fulltext_searched)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2014 2015 2016
	  {
	    if (const_ref == eq_part)
	    {					// Found everything for ref.
2017 2018
	      int tmp;
	      ref_changed = 1;
2019
	      s->type= JT_CONST;
2020
	      join->const_table_map|=table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2021
	      set_position(join,const_count++,s,start_keyuse);
2022
	      if (create_ref_for_key(join, s, start_keyuse,
2023
				     found_const_table_map))
2024 2025 2026 2027 2028 2029 2030 2031 2032
		DBUG_RETURN(1);
	      if ((tmp=join_read_const_table(s,
					     join->positions+const_count-1)))
	      {
		if (tmp > 0)
		  DBUG_RETURN(1);			// Fatal error
	      }
	      else
		found_const_table_map|= table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2033 2034 2035 2036 2037 2038 2039 2040
	      break;
	    }
	    else
	      found_ref|= refs;		// Table is const if all refs are const
	  }
	}
      }
    }
2041
  } while (join->const_table_map & found_ref && ref_changed);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054

  /* Calc how many (possible) matched records in each table */

  for (s=stat ; s < stat_end ; s++)
  {
    if (s->type == JT_SYSTEM || s->type == JT_CONST)
    {
      /* Only one matching row */
      s->found_records=s->records=s->read_time=1; s->worst_seeks=1.0;
      continue;
    }
    /* Approximate found rows and time to read them */
    s->found_records=s->records=s->table->file->records;
2055
    s->read_time=(ha_rows) s->table->file->scan_time();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2056

2057 2058
    /*
      Set a max range of how many seeks we can expect when using keys
2059 2060
      This is can't be to high as otherwise we are likely to use
      table scan.
2061
    */
2062 2063
    s->worst_seeks= min((double) s->found_records / 10,
			(double) s->read_time*3);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2064 2065 2066
    if (s->worst_seeks < 2.0)			// Fix for small tables
      s->worst_seeks=2.0;

2067
    if (! s->const_keys.is_clear_all())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2068 2069
    {
      ha_rows records;
2070 2071 2072 2073 2074
      SQL_SELECT *select;
      select= make_select(s->table, found_const_table_map,
			  found_const_table_map,
			  s->on_expr ? s->on_expr : conds,
			  &error);
2075
      records= get_quick_record_count(join->thd, select, s->table,
serg@serg.mylan's avatar
serg@serg.mylan committed
2076
				      &s->const_keys, join->row_limit);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2077 2078 2079
      s->quick=select->quick;
      s->needed_reg=select->needed_reg;
      select->quick=0;
2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
      if (records == 0 && s->table->reginfo.impossible_range)
      {
	/*
	  Impossible WHERE or ON expression
	  In case of ON, we mark that the we match one empty NULL row.
	  In case of WHERE, don't set found_const_table_map to get the
	  caller to abort with a zero row result.
	*/
	join->const_table_map|= s->table->map;
	set_position(join,const_count++,s,(KEYUSE*) 0);
	s->type= JT_CONST;
	if (s->on_expr)
	{
	  /* Generate empty row */
	  s->info= "Impossible ON condition";
	  found_const_table_map|= s->table->map;
	  s->type= JT_CONST;
	  mark_as_null_row(s->table);		// All fields are NULL
	}
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2100 2101
      if (records != HA_POS_ERROR)
      {
2102
	s->found_records=records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2103 2104
	s->read_time= (ha_rows) (s->quick ? s->quick->read_time : 0.0);
      }
2105
      delete select;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2106 2107 2108 2109 2110 2111 2112 2113
    }
  }

  /* Find best combination and return it */
  join->join_tab=stat;
  join->map2table=stat_ref;
  join->table= join->all_tables=table_vector;
  join->const_tables=const_count;
2114
  join->found_const_table_map=found_const_table_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2115 2116

  if (join->const_tables != join->tables)
2117 2118
  {
    optimize_keyuse(join, keyuse_array);
2119
    find_best_combination(join,all_table_map & ~join->const_table_map);
2120
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2121 2122 2123 2124 2125 2126
  else
  {
    memcpy((gptr) join->best_positions,(gptr) join->positions,
	   sizeof(POSITION)*join->const_tables);
    join->best_read=1.0;
  }
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
2127
  DBUG_RETURN(join->thd->killed || get_best_combination(join));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2128 2129 2130 2131
}


/*****************************************************************************
2132 2133 2134 2135 2136
  Check with keys are used and with tables references with tables
  Updates in stat:
	  keys	     Bitmap of all used keys
	  const_keys Bitmap of all keys with may be used with quick_select
	  keyuse     Pointer to possible keys
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2137 2138 2139 2140 2141
*****************************************************************************/

typedef struct key_field_t {		// Used when finding key fields
  Field		*field;
  Item		*val;			// May be empty if diff constant
2142 2143
  uint		level;
  uint		optimize;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2144
  bool		eq_func;
2145 2146 2147 2148 2149
  /*
    If true, the condition this struct represents will not be satisfied
    when val IS NULL.
  */
  bool          null_rejecting; 
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2150 2151
} KEY_FIELD;

2152 2153 2154 2155 2156 2157 2158 2159
/* Values in optimize */
#define KEY_OPTIMIZE_EXISTS		1
#define KEY_OPTIMIZE_REF_OR_NULL	2

/*
  Merge new key definitions to old ones, remove those not used in both

  This is called for OR between different levels
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2160

2161 2162 2163 2164 2165
  To be able to do 'ref_or_null' we merge a comparison of a column
  and 'column IS NULL' to one test.  This is useful for sub select queries
  that are internally transformed to something like:

  SELECT * FROM t1 WHERE t1.key=outer_ref_field or t1.key IS NULL 
2166 2167 2168 2169 2170 2171

  KEY_FIELD::null_rejecting is processed as follows:
  result has null_rejecting=true if it is set for both ORed references.
  for example:
    (t2.key = t1.field OR t2.key  =  t1.field) -> null_rejecting=true
    (t2.key = t1.field OR t2.key <=> t1.field) -> null_rejecting=false
2172
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2173 2174 2175 2176 2177 2178 2179 2180

static KEY_FIELD *
merge_key_fields(KEY_FIELD *start,KEY_FIELD *new_fields,KEY_FIELD *end,
		 uint and_level)
{
  if (start == new_fields)
    return start;				// Impossible or
  if (new_fields == end)
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2181
    return start;				// No new fields, skip all
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193

  KEY_FIELD *first_free=new_fields;

  /* Mark all found fields in old array */
  for (; new_fields != end ; new_fields++)
  {
    for (KEY_FIELD *old=start ; old != first_free ; old++)
    {
      if (old->field == new_fields->field)
      {
	if (new_fields->val->used_tables())
	{
2194 2195 2196 2197
	  /*
	    If the value matches, we can use the key reference.
	    If not, we keep it until we have examined all new values
	  */
2198
	  if (old->val->eq(new_fields->val, old->field->binary()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2199
	  {
2200 2201 2202 2203 2204
	    old->level= and_level;
	    old->optimize= ((old->optimize & new_fields->optimize &
			     KEY_OPTIMIZE_EXISTS) |
			    ((old->optimize | new_fields->optimize) &
			     KEY_OPTIMIZE_REF_OR_NULL));
monty@mysql.com's avatar
monty@mysql.com committed
2205 2206
            old->null_rejecting= (old->null_rejecting &&
                                  new_fields->null_rejecting);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2207 2208
	  }
	}
2209 2210
	else if (old->eq_func && new_fields->eq_func &&
		 old->val->eq(new_fields->val, old->field->binary()))
2211

2212 2213 2214 2215 2216 2217
	{
	  old->level= and_level;
	  old->optimize= ((old->optimize & new_fields->optimize &
			   KEY_OPTIMIZE_EXISTS) |
			  ((old->optimize | new_fields->optimize) &
			   KEY_OPTIMIZE_REF_OR_NULL));
monty@mysql.com's avatar
monty@mysql.com committed
2218 2219
          old->null_rejecting= (old->null_rejecting &&
                                new_fields->null_rejecting);
2220 2221
	}
	else if (old->eq_func && new_fields->eq_func &&
2222 2223
		 ((!old->val->used_tables() && old->val->is_null()) || 
                  new_fields->val->is_null()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2224
	{
2225 2226 2227
	  /* field = expression OR field IS NULL */
	  old->level= and_level;
	  old->optimize= KEY_OPTIMIZE_REF_OR_NULL;
2228 2229 2230 2231 2232
	  /*
            Remember the NOT NULL value unless the value does not depend
            on other tables.
          */
	  if (!old->val->used_tables() && old->val->is_null())
2233
	    old->val= new_fields->val;
2234
          /* The referred expression can be NULL: */ 
monty@mysql.com's avatar
monty@mysql.com committed
2235
          old->null_rejecting= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2236
	}
2237
	else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2238
	{
2239 2240 2241 2242 2243
	  /*
	    We are comparing two different const.  In this case we can't
	    use a key-lookup on this so it's better to remove the value
	    and let the range optimzier handle it
	  */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254
	  if (old == --first_free)		// If last item
	    break;
	  *old= *first_free;			// Remove old value
	  old--;				// Retry this value
	}
      }
    }
  }
  /* Remove all not used items */
  for (KEY_FIELD *old=start ; old != first_free ;)
  {
2255
    if (old->level != and_level)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267
    {						// Not used in all levels
      if (old == --first_free)
	break;
      *old= *first_free;			// Remove old value
      continue;
    }
    old++;
  }
  return first_free;
}


2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
/*
  Add a possible key to array of possible keys if it's usable as a key

  SYNPOSIS
    add_key_field()
    key_fields			Pointer to add key, if usable
    and_level			And level, to be stored in KEY_FIELD
    field			Field used in comparision
    eq_func			True if we used =, <=> or IS NULL
    value			Value used for comparison with field
    usable_tables		Tables which can be used for key optimization

  NOTES
    If we are doing a NOT NULL comparison on a NOT NULL field in a outer join
    table, we store this to be able to do not exists optimization later.

  RETURN
    *key_fields is incremented if we stored a key in the array
*/

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2288
static void
2289
add_key_field(KEY_FIELD **key_fields,uint and_level, Item_func *cond,
2290
	      Field *field,bool eq_func,Item **value, uint num_values,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2291 2292
	      table_map usable_tables)
{
2293
  uint exists_optimize= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2294 2295 2296
  if (!(field->flags & PART_KEY_FLAG))
  {
    // Don't remove column IS NULL on a LEFT JOIN table
2297 2298
    if (!eq_func || (*value)->type() != Item::NULL_ITEM ||
        !field->table->maybe_null || field->null_ptr)
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2299
      return;					// Not a key. Skip it
2300
    exists_optimize= KEY_OPTIMIZE_EXISTS;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2301 2302 2303 2304
  }
  else
  {
    table_map used_tables=0;
2305 2306 2307
    bool optimizable=0;
    for (uint i=0; i<num_values; i++)
    {
2308 2309
      used_tables|=(value[i])->used_tables();
      if (!((value[i])->used_tables() & (field->table->map | RAND_TABLE_BIT)))
2310 2311 2312
        optimizable=1;
    }
    if (!optimizable)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2313 2314 2315
      return;
    if (!(usable_tables & field->table->map))
    {
2316 2317
      if (!eq_func || (*value)->type() != Item::NULL_ITEM ||
          !field->table->maybe_null || field->null_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2318
	return;					// Can't use left join optimize
2319
      exists_optimize= KEY_OPTIMIZE_EXISTS;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2320 2321 2322 2323
    }
    else
    {
      JOIN_TAB *stat=field->table->reginfo.join_tab;
serg@serg.mylan's avatar
serg@serg.mylan committed
2324
      key_map possible_keys=field->key_start;
2325 2326
      possible_keys.intersect(field->table->keys_in_use_for_query);
      stat[0].keys.merge(possible_keys);             // Add possible keys
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2327

2328 2329 2330 2331 2332 2333 2334 2335
      /*
	Save the following cases:
	Field op constant
	Field LIKE constant where constant doesn't start with a wildcard
	Field = field2 where field2 is in a different table
	Field op formula
	Field IS NULL
	Field IS NOT NULL
2336 2337
         Field BETWEEN ...
         Field IN ...
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2338 2339 2340
      */
      stat[0].key_dependent|=used_tables;

2341 2342
      bool is_const=1;
      for (uint i=0; i<num_values; i++)
2343
        is_const&= value[i]->const_item();
2344
      if (is_const)
2345
        stat[0].const_keys.merge(possible_keys);
2346 2347
      /*
	We can't always use indexes when comparing a string index to a
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2348 2349
	number. cmp_type() is checked to allow compare of dates to numbers.
        eq_func is NEVER true when num_values > 1
2350
       */
monty@mysql.com's avatar
monty@mysql.com committed
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364
      if (!eq_func)
        return;
      if (field->result_type() == STRING_RESULT)
      {
        if ((*value)->result_type() != STRING_RESULT)
        {
          if (field->cmp_type() != (*value)->result_type())
            return;
        }
        else
        {
          /*
            We can't use indexes if the effective collation
            of the operation differ from the field collation.
2365

monty@mysql.com's avatar
monty@mysql.com committed
2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
            We can also not used index on a text column, as the column may
            contain 'x' 'x\t' 'x ' and 'read_next_same' will stop after
            'x' when searching for WHERE col='x '
          */
          if (field->cmp_type() == STRING_RESULT &&
              (((Field_str*)field)->charset() != cond->compare_collation() ||
               ((*value)->type() != Item::NULL_ITEM &&
                (field->flags & BLOB_FLAG) && !field->binary())))
            return;
        }
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2377 2378
    }
  }
2379
  DBUG_ASSERT(num_values == 1);
2380 2381 2382 2383 2384
  /*
    For the moment eq_func is always true. This slot is reserved for future
    extensions where we want to remembers other things than just eq comparisons
  */
  DBUG_ASSERT(eq_func);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2385
  /* Store possible eq field */
2386 2387
  (*key_fields)->field=		field;
  (*key_fields)->eq_func=	eq_func;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2388
  (*key_fields)->val=		*value;
2389 2390
  (*key_fields)->level=		and_level;
  (*key_fields)->optimize=	exists_optimize;
2391 2392 2393 2394
  /*
    If the condition has form "tbl.keypart = othertbl.field" and 
    othertbl.field can be NULL, there will be no matches if othertbl.field 
    has NULL value.
monty@mysql.com's avatar
monty@mysql.com committed
2395 2396
    We use null_rejecting in add_not_null_conds() to add
    'othertbl.field IS NOT NULL' to tab->select_cond.
2397
  */
monty@mysql.com's avatar
monty@mysql.com committed
2398
  (*key_fields)->null_rejecting= ((cond->functype() == Item_func::EQ_FUNC) &&
2399
                                 ((*value)->type() == Item::FIELD_ITEM) &&
monty@mysql.com's avatar
monty@mysql.com committed
2400
                                  ((Item_field*)*value)->field->maybe_null());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2401 2402 2403
  (*key_fields)++;
}

2404 2405 2406 2407 2408 2409 2410 2411 2412 2413
/*
  SYNOPSIS
    add_key_fields()
      key_fields      Add KEY_FIELD entries to this array (and move the 
                      pointer)
      and_level       AND-level (a value that is different for every n-way
                      AND operation)
      cond            Condition to analyze
      usable_tables   Value to pass to add_key_field
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2414
static void
2415
add_key_fields(KEY_FIELD **key_fields,uint *and_level,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2416 2417 2418 2419
	       COND *cond, table_map usable_tables)
{
  if (cond->type() == Item_func::COND_ITEM)
  {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
2420
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2421 2422 2423 2424 2425 2426
    KEY_FIELD *org_key_fields= *key_fields;

    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
      Item *item;
      while ((item=li++))
2427
	add_key_fields(key_fields,and_level,item,usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2428
      for (; org_key_fields != *key_fields ; org_key_fields++)
2429
	org_key_fields->level= *and_level;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2430 2431 2432 2433
    }
    else
    {
      (*and_level)++;
2434
      add_key_fields(key_fields,and_level,li++,usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2435 2436 2437 2438 2439
      Item *item;
      while ((item=li++))
      {
	KEY_FIELD *start_key_fields= *key_fields;
	(*and_level)++;
2440
	add_key_fields(key_fields,and_level,item,usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455
	*key_fields=merge_key_fields(org_key_fields,start_key_fields,
				     *key_fields,++(*and_level));
      }
    }
    return;
  }
  /* If item is of type 'field op field/constant' add it to key_fields */

  if (cond->type() != Item::FUNC_ITEM)
    return;
  Item_func *cond_func= (Item_func*) cond;
  switch (cond_func->select_optimize()) {
  case Item_func::OPTIMIZE_NONE:
    break;
  case Item_func::OPTIMIZE_KEY:
serg@serg.mylan's avatar
serg@serg.mylan committed
2456
    // BETWEEN, IN, NOT
2457
    if (cond_func->key_item()->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2458
	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
2459
      add_key_field(key_fields,*and_level,cond_func,
serg@serg.mylan's avatar
serg@serg.mylan committed
2460 2461
		    ((Item_field*)(cond_func->key_item()->real_item()))->field,
                    cond_func->argument_count() == 2 &&
2462 2463
                    cond_func->functype() == Item_func::IN_FUNC &&
                    !((Item_func_in*)cond_func)->negated,
2464 2465
                    cond_func->arguments()+1, cond_func->argument_count()-1,
                    usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2466 2467 2468 2469 2470 2471
    break;
  case Item_func::OPTIMIZE_OP:
  {
    bool equal_func=(cond_func->functype() == Item_func::EQ_FUNC ||
		     cond_func->functype() == Item_func::EQUAL_FUNC);

2472
    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2473
	!(cond_func->arguments()[0]->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2474
    {
2475
      add_key_field(key_fields,*and_level,cond_func,
2476 2477
		    ((Item_field*) (cond_func->arguments()[0])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2478
		    equal_func,
2479
                    cond_func->arguments()+1, 1, usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2480
    }
2481
    if (cond_func->arguments()[1]->real_item()->type() == Item::FIELD_ITEM &&
2482
	cond_func->functype() != Item_func::LIKE_FUNC &&
2483
	!(cond_func->arguments()[1]->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2484
    {
2485
      add_key_field(key_fields,*and_level,cond_func,
2486 2487
		    ((Item_field*) (cond_func->arguments()[1])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2488
		    equal_func,
2489
		    cond_func->arguments(),1,usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2490 2491 2492 2493 2494
    }
    break;
  }
  case Item_func::OPTIMIZE_NULL:
    /* column_name IS [NOT] NULL */
2495
    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2496
	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2497
    {
2498
      Item *tmp=new Item_null;
2499
      if (unlikely(!tmp))                       // Should never be true
2500
	return;
2501
      add_key_field(key_fields,*and_level,cond_func,
2502 2503
		    ((Item_field*) (cond_func->arguments()[0])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2504
		    cond_func->functype() == Item_func::ISNULL_FUNC,
2505
		    &tmp, 1, usable_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2506 2507 2508 2509 2510 2511 2512
    }
    break;
  }
  return;
}

/*
2513 2514
  Add all keys with uses 'field' for some keypart
  If field->and_level != and_level then only mark key_part as const_part
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2515 2516 2517
*/

static uint
2518
max_part_bit(key_part_map bits)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531
{
  uint found;
  for (found=0; bits & 1 ; found++,bits>>=1) ;
  return found;
}

static void
add_key_part(DYNAMIC_ARRAY *keyuse_array,KEY_FIELD *key_field)
{
  Field *field=key_field->field;
  TABLE *form= field->table;
  KEYUSE keyuse;

2532
  if (key_field->eq_func && !(key_field->optimize & KEY_OPTIMIZE_EXISTS))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2533 2534 2535
  {
    for (uint key=0 ; key < form->keys ; key++)
    {
2536
      if (!(form->keys_in_use_for_query.is_set(key)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549
	continue;
      if (form->key_info[key].flags & HA_FULLTEXT)
	continue;    // ToDo: ft-keys in non-ft queries.   SerG

      uint key_parts= (uint) form->key_info[key].key_parts;
      for (uint part=0 ; part <  key_parts ; part++)
      {
	if (field->eq(form->key_info[key].key_part[part].field))
	{
	  keyuse.table= field->table;
	  keyuse.val =  key_field->val;
	  keyuse.key =  key;
	  keyuse.keypart=part;
2550
	  keyuse.keypart_map= (key_part_map) 1 << part;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2551
	  keyuse.used_tables=key_field->val->used_tables();
2552
	  keyuse.optimize= key_field->optimize & KEY_OPTIMIZE_REF_OR_NULL;
2553
          keyuse.null_rejecting= key_field->null_rejecting;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2554 2555 2556 2557 2558 2559 2560
	  VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
	}
      }
    }
  }
}

monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2561 2562 2563

#define FT_KEYPART   (MAX_REF_PARTS+10)

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2564 2565 2566 2567
static void
add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
            JOIN_TAB *stat,COND *cond,table_map usable_tables)
{
2568
  Item_func_match *cond_func=NULL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2569

2570 2571 2572
  if (!cond)
    return;

2573 2574
  if (cond->type() == Item::FUNC_ITEM)
  {
2575 2576 2577
    Item_func *func=(Item_func *)cond;
    Item_func::Functype functype=  func->functype();
    if (functype == Item_func::FT_FUNC)
2578
      cond_func=(Item_func_match *)cond;
2579 2580 2581 2582
    else if (func->arg_count == 2)
    {
      Item_func *arg0=(Item_func *)(func->arguments()[0]),
                *arg1=(Item_func *)(func->arguments()[1]);
2583 2584 2585 2586 2587
      if (arg1->const_item()  &&
          ((functype == Item_func::GE_FUNC && arg1->val()> 0) ||
           (functype == Item_func::GT_FUNC && arg1->val()>=0))  &&
           arg0->type() == Item::FUNC_ITEM            &&
           arg0->functype() == Item_func::FT_FUNC)
2588
        cond_func=(Item_func_match *) arg0;
2589 2590 2591
      else if (arg0->const_item() &&
               ((functype == Item_func::LE_FUNC && arg0->val()> 0) ||
                (functype == Item_func::LT_FUNC && arg0->val()>=0)) &&
2592
                arg1->type() == Item::FUNC_ITEM          &&
2593
                arg1->functype() == Item_func::FT_FUNC)
2594 2595
        cond_func=(Item_func_match *) arg1;
    }
2596 2597 2598
  }
  else if (cond->type() == Item::COND_ITEM)
  {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
2599
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
2600 2601 2602 2603 2604

    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
      Item *item;
      while ((item=li++))
2605
        add_ft_keys(keyuse_array,stat,item,usable_tables);
2606 2607 2608
    }
  }

2609 2610
  if (!cond_func || cond_func->key == NO_SUCH_KEY ||
      !(usable_tables & cond_func->table->map))
2611
    return;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2612 2613 2614

  KEYUSE keyuse;
  keyuse.table= cond_func->table;
2615
  keyuse.val =  cond_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2616
  keyuse.key =  cond_func->key;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2617
  keyuse.keypart= FT_KEYPART;
2618
  keyuse.used_tables=cond_func->key_item()->used_tables();
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2619
  keyuse.optimize= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2620
  keyuse.keypart_map= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2621 2622 2623
  VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
}

2624

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2625 2626 2627
static int
sort_keyuse(KEYUSE *a,KEYUSE *b)
{
2628
  int res;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2629 2630 2631 2632 2633 2634
  if (a->table->tablenr != b->table->tablenr)
    return (int) (a->table->tablenr - b->table->tablenr);
  if (a->key != b->key)
    return (int) (a->key - b->key);
  if (a->keypart != b->keypart)
    return (int) (a->keypart - b->keypart);
2635
  // Place const values before other ones
2636 2637
  if ((res= test((a->used_tables & ~OUTER_REF_TABLE_BIT)) -
       test((b->used_tables & ~OUTER_REF_TABLE_BIT))))
2638 2639 2640 2641
    return res;
  /* Place rows that are not 'OPTIMIZE_REF_OR_NULL' first */
  return (int) ((a->optimize & KEY_OPTIMIZE_REF_OR_NULL) -
		(b->optimize & KEY_OPTIMIZE_REF_OR_NULL));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2642 2643 2644 2645
}


/*
2646
  Update keyuse array with all possible keys we can use to fetch rows
2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662
  
  SYNOPSIS
    update_ref_and_keys()
      thd 
      keyuse     OUT Put here ordered array of KEYUSE structures
      join_tab       Array in tablenr_order
      tables         Number of tables in join
      cond           WHERE condition (note that the function analyzes 
                     join_tab[i]->on_expr too)
      normal_tables  tables not inner w.r.t some outer join (ones for which
                     we can make ref access based the WHERE clause)
      select_lex     current SELECT
      
  RETURN 
   0 - OK
   1 - Out of memory.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2663 2664 2665
*/

static bool
2666
update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
2667 2668
		    uint tables, COND *cond, table_map normal_tables,
		    SELECT_LEX *select_lex)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2669 2670
{
  uint	and_level,i,found_eq_constant;
monty@mysql.com's avatar
monty@mysql.com committed
2671
  KEY_FIELD *key_fields, *end, *field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2672

2673
  if (!(key_fields=(KEY_FIELD*)
monty@mashka.mysql.fi's avatar
merge  
monty@mashka.mysql.fi committed
2674
	thd->alloc(sizeof(key_fields[0])*
2675
		   (thd->lex->current_select->cond_count+1)*2)))
2676
    return TRUE; /* purecov: inspected */
monty@mysql.com's avatar
monty@mysql.com committed
2677 2678 2679 2680
  and_level= 0;
  field= end= key_fields;
  if (my_init_dynamic_array(keyuse,sizeof(KEYUSE),20,64))
    return TRUE;
2681
  if (cond)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2682
  {
2683
    add_key_fields(&end,&and_level,cond,normal_tables);
monty@mysql.com's avatar
monty@mysql.com committed
2684
    for (; field != end ; field++)
hf@deer.(none)'s avatar
hf@deer.(none) committed
2685
    {
monty@mysql.com's avatar
monty@mysql.com committed
2686 2687 2688 2689 2690
      add_key_part(keyuse,field);
      /* Mark that we can optimize LEFT JOIN */
      if (field->val->type() == Item::NULL_ITEM &&
	  !field->field->real_maybe_null())
	field->field->table->reginfo.not_exists_optimize=1;
hf@deer.(none)'s avatar
hf@deer.(none) committed
2691
    }
monty@mysql.com's avatar
monty@mysql.com committed
2692
  }
2693
  for (i=0 ; i < tables ; i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2694
  {
2695
    if (join_tab[i].on_expr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2696
    {
2697
      add_key_fields(&end,&and_level,join_tab[i].on_expr,
2698
		     join_tab[i].table->map);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2699 2700
    }
  }
2701
  /* fill keyuse with found key parts */
monty@mysql.com's avatar
monty@mysql.com committed
2702
  for ( ; field != end ; field++)
2703
    add_key_part(keyuse,field);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2704

2705
  if (select_lex->ftfunc_list->elements)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2706 2707 2708 2709 2710
  {
    add_ft_keys(keyuse,join_tab,cond,normal_tables);
  }

  /*
2711
    Special treatment for ft-keys.
2712 2713 2714
    Remove the following things from KEYUSE:
    - ref if there is a keypart which is a ref and a const.
    - keyparts without previous keyparts.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731
  */
  if (keyuse->elements)
  {
    KEYUSE end,*prev,*save_pos,*use;

    qsort(keyuse->buffer,keyuse->elements,sizeof(KEYUSE),
	  (qsort_cmp) sort_keyuse);

    bzero((char*) &end,sizeof(end));		/* Add for easy testing */
    VOID(insert_dynamic(keyuse,(gptr) &end));

    use=save_pos=dynamic_element(keyuse,0,KEYUSE*);
    prev=&end;
    found_eq_constant=0;
    for (i=0 ; i < keyuse->elements-1 ; i++,use++)
    {
      if (!use->used_tables)
2732
	use->table->const_key_parts[use->key]|= use->keypart_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2733 2734
      if (use->keypart != FT_KEYPART)
      {
2735 2736 2737 2738 2739 2740 2741 2742
	if (use->key == prev->key && use->table == prev->table)
	{
	  if (prev->keypart+1 < use->keypart ||
	      prev->keypart == use->keypart && found_eq_constant)
	    continue;				/* remove */
	}
	else if (use->keypart != 0)		// First found must be 0
	  continue;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2743 2744 2745 2746 2747 2748 2749 2750
      }

      *save_pos= *use;
      prev=use;
      found_eq_constant= !use->used_tables;
      /* Save ptr to first use */
      if (!use->table->reginfo.join_tab->keyuse)
	use->table->reginfo.join_tab->keyuse=save_pos;
2751
      use->table->reginfo.join_tab->checked_keys.set_bit(use->key);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2752 2753 2754 2755 2756 2757 2758 2759 2760
      save_pos++;
    }
    i=(uint) (save_pos-(KEYUSE*) keyuse->buffer);
    VOID(set_dynamic(keyuse,(gptr) &end,i));
    keyuse->elements=i;
  }
  return FALSE;
}

2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
/*
  Update some values in keyuse for faster find_best_combination() loop
*/

static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array)
{
  KEYUSE *end,*keyuse= dynamic_element(keyuse_array, 0, KEYUSE*);

  for (end= keyuse+ keyuse_array->elements ; keyuse < end ; keyuse++)
  {
    table_map map;
    /*
      If we find a ref, assume this table matches a proportional
      part of this table.
      For example 100 records matching a table with 5000 records
      gives 5000/100 = 50 records per key
      Constant tables are ignored.
      To avoid bad matches, we don't make ref_table_rows less than 100.
    */
serg@serg.mylan's avatar
serg@serg.mylan committed
2780
    keyuse->ref_table_rows= ~(ha_rows) 0;	// If no ref
2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792
    if (keyuse->used_tables &
	(map= (keyuse->used_tables & ~join->const_table_map &
	       ~OUTER_REF_TABLE_BIT)))
    {
      uint tablenr;
      for (tablenr=0 ; ! (map & 1) ; map>>=1, tablenr++) ;
      if (map == 1)			// Only one table
      {
	TABLE *tmp_table=join->all_tables[tablenr];
	keyuse->ref_table_rows= max(tmp_table->file->records, 100);
      }
    }
2793 2794 2795 2796 2797 2798
    /*
      Outer reference (external field) is constant for single executing
      of subquery
    */
    if (keyuse->used_tables == OUTER_REF_TABLE_BIT)
      keyuse->ref_table_rows= 1;
2799 2800 2801
  }
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2802 2803

/*****************************************************************************
2804 2805
  Go through all combinations of not marked tables and find the one
  which uses least records
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819
*****************************************************************************/

/* Save const tables first as used tables */

static void
set_position(JOIN *join,uint idx,JOIN_TAB *table,KEYUSE *key)
{
  join->positions[idx].table= table;
  join->positions[idx].key=key;
  join->positions[idx].records_read=1.0;	/* This is a const table */

  /* Move the const table as down as possible in best_ref */
  JOIN_TAB **pos=join->best_ref+idx+1;
  JOIN_TAB *next=join->best_ref[idx];
2820
  for (;next != table ; pos++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843
  {
    JOIN_TAB *tmp=pos[0];
    pos[0]=next;
    next=tmp;
  }
  join->best_ref[idx]=table;
}


static void
find_best_combination(JOIN *join, table_map rest_tables)
{
  DBUG_ENTER("find_best_combination");
  join->best_read=DBL_MAX;
  find_best(join,rest_tables, join->const_tables,1.0,0.0);
  DBUG_VOID_RETURN;
}


static void
find_best(JOIN *join,table_map rest_tables,uint idx,double record_count,
	  double read_time)
{
2844
  ha_rows rec;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2845
  double tmp;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2846
  THD *thd= join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2847 2848 2849 2850 2851 2852 2853 2854

  if (!rest_tables)
  {
    DBUG_PRINT("best",("read_time: %g  record_count: %g",read_time,
		       record_count));

    read_time+=record_count/(double) TIME_FOR_COMPARE;
    if (join->sort_by_table &&
2855 2856
	join->sort_by_table !=
	join->positions[join->const_tables].table->table)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878
      read_time+=record_count;			// We have to make a temp table
    if (read_time < join->best_read)
    {
      memcpy((gptr) join->best_positions,(gptr) join->positions,
	     sizeof(POSITION)*idx);
      join->best_read=read_time;
    }
    return;
  }
  if (read_time+record_count/(double) TIME_FOR_COMPARE >= join->best_read)
    return;					/* Found better before */

  JOIN_TAB *s;
  double best_record_count=DBL_MAX,best_read_time=DBL_MAX;
  for (JOIN_TAB **pos=join->best_ref+idx ; (s=*pos) ; pos++)
  {
    table_map real_table_bit=s->table->map;
    if ((rest_tables & real_table_bit) && !(rest_tables & s->dependent))
    {
      double best,best_time,records;
      best=best_time=records=DBL_MAX;
      KEYUSE *best_key=0;
2879
      uint best_max_key_part=0;
2880
      my_bool found_constraint= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2881 2882 2883 2884 2885 2886

      if (s->keyuse)
      {						/* Use key if possible */
	TABLE *table=s->table;
	KEYUSE *keyuse,*start_key=0;
	double best_records=DBL_MAX;
2887
	uint max_key_part=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2888 2889

	/* Test how we can use keys */
2890
	rec= s->records/MATCHING_ROWS_IN_OTHER_TABLE;  // Assumed records/key
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2891 2892
	for (keyuse=s->keyuse ; keyuse->table == table ;)
	{
2893
	  key_part_map found_part=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2894 2895 2896 2897
	  table_map found_ref=0;
	  uint key=keyuse->key;
	  KEY *keyinfo=table->key_info+key;
          bool ft_key=(keyuse->keypart == FT_KEYPART);
2898
	  uint found_ref_or_null= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2899

2900
	  /* Calculate how many key segments of the current key we can use */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2901 2902 2903 2904
	  start_key=keyuse;
	  do
	  {
            uint keypart=keyuse->keypart;
monty@mysql.com's avatar
monty@mysql.com committed
2905 2906
            table_map best_part_found_ref= 0;
            double best_prev_record_reads= DBL_MAX;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2907 2908
	    do
	    {
2909 2910 2911 2912
	      if (!(rest_tables & keyuse->used_tables) &&
		  !(found_ref_or_null & keyuse->optimize))
	      {
		found_part|=keyuse->keypart_map;
monty@mysql.com's avatar
monty@mysql.com committed
2913 2914 2915 2916 2917 2918 2919 2920
                double tmp= prev_record_reads(join,
					      (found_ref |
					       keyuse->used_tables));
                if (tmp < best_prev_record_reads)
                {
                  best_part_found_ref= keyuse->used_tables;
                  best_prev_record_reads= tmp;
                }
2921 2922
		if (rec > keyuse->ref_table_rows)
		  rec= keyuse->ref_table_rows;
monty@mysql.com's avatar
monty@mysql.com committed
2923 2924
		/*
		  If there is one 'key_column IS NULL' expression, we can
2925
		  use this ref_or_null optimisation of this field
monty@mysql.com's avatar
monty@mysql.com committed
2926 2927 2928
		*/
		found_ref_or_null|= (keyuse->optimize &
				     KEY_OPTIMIZE_REF_OR_NULL);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2929 2930 2931 2932
              }
	      keyuse++;
	    } while (keyuse->table == table && keyuse->key == key &&
		     keyuse->keypart == keypart);
monty@mysql.com's avatar
monty@mysql.com committed
2933
	    found_ref|= best_part_found_ref;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2934 2935 2936
	  } while (keyuse->table == table && keyuse->key == key);

	  /*
2937
	    Assume that that each key matches a proportional part of table.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2938 2939 2940
	  */
          if (!found_part && !ft_key)
	    continue;				// Nothing usable found
2941 2942
	  if (rec < MATCHING_ROWS_IN_OTHER_TABLE)
	    rec= MATCHING_ROWS_IN_OTHER_TABLE;	// Fix for small tables
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2943 2944

          /*
2945
	    ft-keys require special treatment
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2946 2947 2948 2949
          */
          if (ft_key)
          {
            /*
2950 2951
	      Really, there should be records=0.0 (yes!)
	      but 1.0 would be probably safer
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2952 2953 2954 2955 2956 2957
            */
            tmp=prev_record_reads(join,found_ref);
            records=1.0;
          }
          else
          {
2958
	  found_constraint= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2959
	  /*
2960
	    Check if we found full key
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2961
	  */
2962 2963
	  if (found_part == PREV_BITS(uint,keyinfo->key_parts) &&
	      !found_ref_or_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2964
	  {				/* use eq key */
2965
	    max_key_part= (uint) ~0;
2966 2967
	    if ((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY |
				   HA_END_SPACE_KEY)) == HA_NOSAME)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2968 2969 2970 2971 2972 2973
	    {
	      tmp=prev_record_reads(join,found_ref);
	      records=1.0;
	    }
	    else
	    {
2974 2975
	      if (!found_ref)
	      {					// We found a const key
2976
		if (table->quick_keys.is_set(key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2977 2978
		  records= (double) table->quick_rows[key];
		else
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2979 2980 2981 2982
		{
		  /* quick_range couldn't use key! */
		  records= (double) s->records/rec;
		}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996
	      }
	      else
	      {
		if (!(records=keyinfo->rec_per_key[keyinfo->key_parts-1]))
		{				// Prefere longer keys
		  records=
		    ((double) s->records / (double) rec *
		     (1.0 +
		      ((double) (table->max_key_length-keyinfo->key_length) /
		       (double) table->max_key_length)));
		  if (records < 2.0)
		    records=2.0;		// Can't be as good as a unique
		}
	      }
2997 2998 2999
	      /* Limit the number of matched rows */
	      tmp= records;
	      set_if_smaller(tmp, (double) thd->variables.max_seeks_for_key);
3000
	      if (table->used_keys.is_set(key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3001 3002 3003
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
3004
		  (keyinfo->key_length+table->file->ref_length)+1;
3005
		tmp=record_count*(tmp+keys_per_block-1)/keys_per_block;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3006 3007
	      }
	      else
3008
		tmp=record_count*min(tmp,s->worst_seeks);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3009 3010 3011 3012 3013
	    }
	  }
	  else
	  {
	    /*
3014 3015 3016
	      Use as much key-parts as possible and a uniq key is better
	      than a not unique key
	      Set tmp to (previous record count) * (records / combination)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3017
	    */
3018
	    if ((found_part & 1) &&
3019
		(!(table->file->index_flags(key,0,0) & HA_ONLY_WHOLE_INDEX) ||
3020
		 found_part == PREV_BITS(uint,keyinfo->key_parts)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3021
	    {
3022
	      max_key_part=max_part_bit(found_part);
3023 3024 3025 3026
	      /*
		Check if quick_range could determinate how many rows we
		will match
	      */
3027
	      if (table->quick_keys.is_set(key) &&
3028
		  table->quick_key_parts[key] == max_key_part)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3029 3030 3031 3032 3033 3034 3035 3036 3037
		tmp=records= (double) table->quick_rows[key];
	      else
	      {
		/* Check if we have statistic about the distribution */
		if ((records=keyinfo->rec_per_key[max_key_part-1]))
		  tmp=records;
		else
		{
		  /*
3038
		    Assume that the first key part matches 1% of the file
3039
		    and that the hole key matches 10 (duplicates) or 1
3040 3041 3042 3043 3044
		    (unique) records.
		    Assume also that more key matches proportionally more
		    records
		    This gives the formula:
		    records= (x * (b-a) + a*c-b)/(c-1)
3045

3046 3047 3048 3049
		    b = records matched by whole key
		    a = records matched by first key part (10% of all records?)
		    c = number of key parts in key
		    x = used key parts (1 <= x <= c)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3050 3051
		  */
		  double rec_per_key;
3052 3053 3054
                  rec_per_key= keyinfo->rec_per_key[keyinfo->key_parts-1] ?
		    (double) keyinfo->rec_per_key[keyinfo->key_parts-1] :
		    (double) s->records/rec+1;   
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068
		  if (!s->records)
		    tmp=0;
		  else if (rec_per_key/(double) s->records >= 0.01)
		    tmp=rec_per_key;
		  else
		  {
		    double a=s->records*0.01;
		    tmp=(max_key_part * (rec_per_key - a) +
			 a*keyinfo->key_parts - rec_per_key)/
		      (keyinfo->key_parts-1);
		    set_if_bigger(tmp,1.0);
		  }
		  records=(ulong) tmp;
		}
3069 3070 3071 3072
		/*
		  If quick_select was used on a part of this key, we know
		  the maximum number of rows that the key can match.
		*/
monty@mysql.com's avatar
monty@mysql.com committed
3073
		if (table->quick_keys.is_set(key) &&
3074 3075 3076
		    table->quick_key_parts[key] <= max_key_part &&
		    records > (double) table->quick_rows[key])
		  tmp= records= (double) table->quick_rows[key];
monty@mysql.com's avatar
monty@mysql.com committed
3077
		else if (found_ref_or_null)
3078 3079 3080 3081 3082
		{
		  /* We need to do two key searches to find key */
		  tmp*= 2.0;
		  records*= 2.0;
		}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3083
	      }
3084 3085
	      /* Limit the number of matched rows */
	      set_if_smaller(tmp, (double) thd->variables.max_seeks_for_key);
3086
	      if (table->used_keys.is_set(key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3087 3088 3089
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
3090
		  (keyinfo->key_length+table->file->ref_length)+1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3091 3092 3093 3094 3095 3096 3097 3098
		tmp=record_count*(tmp+keys_per_block-1)/keys_per_block;
	      }
	      else
		tmp=record_count*min(tmp,s->worst_seeks);
	    }
	    else
	      tmp=best_time;			// Do nothing
	  }
3099
          } /* not ft_key */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3100 3101 3102 3103 3104 3105
	  if (tmp < best_time - records/(double) TIME_FOR_COMPARE)
	  {
	    best_time=tmp + records/(double) TIME_FOR_COMPARE;
	    best=tmp;
	    best_records=records;
	    best_key=start_key;
3106
	    best_max_key_part=max_key_part;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3107 3108 3109 3110
	  }
	}
	records=best_records;
      }
3111 3112 3113 3114

      /*
	Don't test table scan if it can't be better.
	Prefer key lookup if we would use the same key for scanning.
3115 3116 3117 3118 3119

	Don't do a table scan on InnoDB tables, if we can read the used
	parts of the row from any of the used index.
	This is because table scans uses index and we would not win
	anything by using a table scan.
3120 3121 3122
      */
      if ((records >= s->found_records || best > s->read_time) &&
	  !(s->quick && best_key && s->quick->index == best_key->key &&
3123
	    best_max_key_part >= s->table->quick_key_parts[best_key->key]) &&
3124
	  !((s->table->file->table_flags() & HA_TABLE_SCAN_ON_INDEX) &&
3125
	    ! s->table->used_keys.is_clear_all() && best_key) &&
3126
	  !(s->table->force_index && best_key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3127
      {						// Check full join
3128 3129 3130 3131 3132 3133 3134 3135 3136 3137
        ha_rows rnd_records= s->found_records;
        /*
          If there is a restriction on the table, assume that 25% of the
          rows can be skipped on next part.
          This is to force tables that this table depends on before this
          table
        */
        if (found_constraint)
          rnd_records-= rnd_records/4;

3138 3139 3140 3141 3142 3143
        /*
          Range optimizer never proposes a RANGE if it isn't better
          than FULL: so if RANGE is present, it's always preferred to FULL.
          Here we estimate its cost.
        */
        if (s->quick)
3144
        {
3145 3146 3147 3148 3149
          /*
            For each record we:
             - read record range through 'quick'
             - skip rows which does not satisfy WHERE constraints
           */
3150
          tmp= record_count *
3151 3152
               (s->quick->read_time +
               (s->found_records - rnd_records)/(double) TIME_FOR_COMPARE);
3153 3154 3155
        }
        else
        {
3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183
          /* Estimate cost of reading table. */
          tmp= s->table->file->scan_time();
          if (s->on_expr)                         // Can't use join cache
          {
            /*
              For each record we have to:
              - read the whole table record 
              - skip rows which does not satisfy join condition
            */
            tmp= record_count *
                 (tmp +     
                 (s->records - rnd_records)/(double) TIME_FOR_COMPARE);
          }
          else
          {
            /* We read the table as many times as join buffer becomes full. */
            tmp*= (1.0 + floor((double) cache_record_length(join,idx) *
                               record_count /
                               (double) thd->variables.join_buff_size));
            /* 
              We don't make full cartesian product between rows in the scanned
              table and existing records because we skip all rows from the
              scanned table, which does not satisfy join condition when 
              we read the table (see flush_cached_records for details). Here we
              take into account cost to read and skip these records.
            */
            tmp+= (s->records - rnd_records)/(double) TIME_FOR_COMPARE;
          }
3184
        }
3185

3186
        /*
3187
          We estimate the cost of evaluating WHERE clause for found records
3188
          as record_count * rnd_records / TIME_FOR_COMPARE. This cost plus
3189
          tmp give us total cost of using TABLE SCAN
3190
        */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3191
	if (best == DBL_MAX ||
3192
	    (tmp  + record_count/(double) TIME_FOR_COMPARE*rnd_records <
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3193 3194
	     best + record_count/(double) TIME_FOR_COMPARE*records))
	{
3195 3196 3197 3198
	  /*
	    If the table has a range (s->quick is set) make_join_select()
	    will ensure that this will be used
	  */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3199
	  best=tmp;
3200
	  records= rows2double(rnd_records);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3201 3202 3203
	  best_key=0;
	}
      }
3204
      join->positions[idx].records_read= records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3205 3206 3207
      join->positions[idx].key=best_key;
      join->positions[idx].table= s;
      if (!best_key && idx == join->const_tables &&
3208
	  s->table == join->sort_by_table &&
3209
	  join->unit->select_limit_cnt >= records)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228
	join->sort_by_table= (TABLE*) 1;	// Must use temporary table

     /*
	Go to the next level only if there hasn't been a better key on
	this level! This will cut down the search for a lot simple cases!
       */
      double current_record_count=record_count*records;
      double current_read_time=read_time+best;
      if (best_record_count > current_record_count ||
	  best_read_time > current_read_time ||
	  idx == join->const_tables && s->table == join->sort_by_table)
      {
	if (best_record_count >= current_record_count &&
	    best_read_time >= current_read_time &&
	    (!(s->key_dependent & rest_tables) || records < 2.0))
	{
	  best_record_count=current_record_count;
	  best_read_time=current_read_time;
	}
3229
	swap_variables(JOIN_TAB*, join->best_ref[idx], *pos);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3230 3231
	find_best(join,rest_tables & ~real_table_bit,idx+1,
		  current_record_count,current_read_time);
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
3232 3233
        if (thd->killed)
          return;
3234
	swap_variables(JOIN_TAB*, join->best_ref[idx], *pos);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3235 3236 3237 3238 3239 3240 3241 3242 3243
      }
      if (join->select_options & SELECT_STRAIGHT_JOIN)
	break;				// Don't test all combinations
    }
  }
}


/*
3244
  Find how much space the prevous read not const tables takes in cache
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3245 3246
*/

3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281
static void calc_used_field_length(THD *thd, JOIN_TAB *join_tab)
{
  uint null_fields,blobs,fields,rec_length;
  null_fields=blobs=fields=rec_length=0;

  Field **f_ptr,*field;
  for (f_ptr=join_tab->table->field ; (field= *f_ptr) ; f_ptr++)
  {
    if (field->query_id == thd->query_id)
    {
      uint flags=field->flags;
      fields++;
      rec_length+=field->pack_length();
      if (flags & BLOB_FLAG)
	blobs++;
      if (!(flags & NOT_NULL_FLAG))
	null_fields++;
    }
  }
  if (null_fields)
    rec_length+=(join_tab->table->null_fields+7)/8;
  if (join_tab->table->maybe_null)
    rec_length+=sizeof(my_bool);
  if (blobs)
  {
    uint blob_length=(uint) (join_tab->table->file->mean_rec_length-
			     (join_tab->table->reclength- rec_length));
    rec_length+=(uint) max(4,blob_length);
  }
  join_tab->used_fields=fields;
  join_tab->used_fieldlength=rec_length;
  join_tab->used_blobs=blobs;
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
3282 3283 3284
static uint
cache_record_length(JOIN *join,uint idx)
{
3285
  uint length=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3286
  JOIN_TAB **pos,**end;
3287
  THD *thd=join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3288 3289 3290 3291 3292 3293

  for (pos=join->best_ref+join->const_tables,end=join->best_ref+idx ;
       pos != end ;
       pos++)
  {
    JOIN_TAB *join_tab= *pos;
3294 3295
    if (!join_tab->used_fieldlength)		/* Not calced yet */
      calc_used_field_length(thd, join_tab);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3296 3297 3298 3299 3300 3301 3302 3303 3304 3305
    length+=join_tab->used_fieldlength;
  }
  return length;
}


static double
prev_record_reads(JOIN *join,table_map found_ref)
{
  double found=1.0;
3306
  found_ref&= ~OUTER_REF_TABLE_BIT;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319
  for (POSITION *pos=join->positions ; found_ref ; pos++)
  {
    if (pos->table->table->map & found_ref)
    {
      found_ref&= ~pos->table->table->map;
      found*=pos->records_read;
    }
  }
  return found;
}


/*****************************************************************************
3320
  Set up join struct according to best position.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3321 3322 3323 3324 3325
*****************************************************************************/

static bool
get_best_combination(JOIN *join)
{
3326
  uint i,tablenr;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3327 3328 3329 3330
  table_map used_tables;
  JOIN_TAB *join_tab,*j;
  KEYUSE *keyuse;
  uint table_count;
3331
  THD *thd=join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3332 3333 3334

  table_count=join->tables;
  if (!(join->join_tab=join_tab=
3335
	(JOIN_TAB*) thd->alloc(sizeof(JOIN_TAB)*table_count)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3336 3337 3338 3339
    return TRUE;

  join->full_join=0;

3340
  used_tables= OUTER_REF_TABLE_BIT;		// Outer row is already read
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3341 3342 3343 3344 3345 3346 3347 3348 3349
  for (j=join_tab, tablenr=0 ; tablenr < table_count ; tablenr++,j++)
  {
    TABLE *form;
    *j= *join->best_positions[tablenr].table;
    form=join->table[tablenr]=j->table;
    used_tables|= form->map;
    form->reginfo.join_tab=j;
    if (!j->on_expr)
      form->reginfo.not_exists_optimize=0;	// Only with LEFT JOIN
3350 3351 3352 3353 3354
    if (j->type == JT_CONST)
      continue;					// Handled in make_join_stat..

    j->ref.key = -1;
    j->ref.key_parts=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3355 3356 3357

    if (j->type == JT_SYSTEM)
      continue;
3358
    if (j->keys.is_clear_all() || !(keyuse= join->best_positions[tablenr].key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3359 3360 3361 3362 3363
    {
      j->type=JT_ALL;
      if (tablenr != join->const_tables)
	join->full_join=1;
    }
3364 3365 3366
    else if (create_ref_for_key(join, j, keyuse, used_tables))
      return TRUE;				// Something went wrong
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3367

3368 3369 3370 3371 3372
  for (i=0 ; i < table_count ; i++)
    join->map2table[join->join_tab[i].table->tablenr]=join->join_tab+i;
  update_depend_map(join);
  return 0;
}
3373

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3374

3375 3376 3377 3378 3379 3380 3381 3382 3383
static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, KEYUSE *org_keyuse,
			       table_map used_tables)
{
  KEYUSE *keyuse=org_keyuse;
  bool ftkey=(keyuse->keypart == FT_KEYPART);
  THD  *thd= join->thd;
  uint keyparts,length,key;
  TABLE *table;
  KEY *keyinfo;
3384

3385
  /*  Use best key from find_best */
3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400
  table=j->table;
  key=keyuse->key;
  keyinfo=table->key_info+key;

  if (ftkey)
  {
    Item_func_match *ifm=(Item_func_match *)keyuse->val;

    length=0;
    keyparts=1;
    ifm->join_key=1;
  }
  else
  {
    keyparts=length=0;
3401 3402 3403 3404 3405 3406
    uint found_part_ref_or_null= 0;
    /*
      Calculate length for the used key
      Stop if there is a missing key part or when we find second key_part
      with KEY_OPTIMIZE_REF_OR_NULL
    */
3407 3408
    do
    {
3409
      if (!(~used_tables & keyuse->used_tables))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3410
      {
3411 3412
	if (keyparts == keyuse->keypart &&
	    !(found_part_ref_or_null & keyuse->optimize))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3413
	{
3414
	  keyparts++;
3415 3416
	  length+= keyinfo->key_part[keyuse->keypart].store_length;
	  found_part_ref_or_null|= keyuse->optimize;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3417 3418
	}
      }
3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436
      keyuse++;
    } while (keyuse->table == table && keyuse->key == key);
  } /* not ftkey */

  /* set up fieldref */
  keyinfo=table->key_info+key;
  j->ref.key_parts=keyparts;
  j->ref.key_length=length;
  j->ref.key=(int) key;
  if (!(j->ref.key_buff= (byte*) thd->calloc(ALIGN_SIZE(length)*2)) ||
      !(j->ref.key_copy= (store_key**) thd->alloc((sizeof(store_key*) *
						   (keyparts+1)))) ||
      !(j->ref.items=    (Item**) thd->alloc(sizeof(Item*)*keyparts)))
  {
    return TRUE;
  }
  j->ref.key_buff2=j->ref.key_buff+ALIGN_SIZE(length);
  j->ref.key_err=1;
3437
  j->ref.null_rejecting= 0;
3438 3439
  keyuse=org_keyuse;

3440 3441
  store_key **ref_key= j->ref.key_copy;
  byte *key_buff=j->ref.key_buff, *null_ref_key= 0;
3442
  bool keyuse_uses_no_tables= TRUE;
3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461
  if (ftkey)
  {
    j->ref.items[0]=((Item_func*)(keyuse->val))->key_item();
    if (keyuse->used_tables)
      return TRUE; // not supported yet. SerG

    j->type=JT_FT;
  }
  else
  {
    uint i;
    for (i=0 ; i < keyparts ; keyuse++,i++)
    {
      while (keyuse->keypart != i ||
	     ((~used_tables) & keyuse->used_tables))
	keyuse++;				/* Skip other parts */

      uint maybe_null= test(keyinfo->key_part[i].null_bit);
      j->ref.items[i]=keyuse->val;		// Save for cond removal
3462 3463
      if (keyuse->null_rejecting) 
        j->ref.null_rejecting |= 1 << i;
3464
      keyuse_uses_no_tables= keyuse_uses_no_tables && !keyuse->used_tables;
3465 3466 3467
      if (!keyuse->used_tables &&
	  !(join->select_options & SELECT_DESCRIBE))
      {					// Compare against constant
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
3468 3469 3470 3471
	store_key_item tmp(thd, keyinfo->key_part[i].field,
                           (char*)key_buff + maybe_null,
                           maybe_null ?  (char*) key_buff : 0,
                           keyinfo->key_part[i].length, keyuse->val);
3472
	if (thd->is_fatal_error)
3473
	  return TRUE;
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
3474
	tmp.copy();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3475 3476
      }
      else
3477 3478 3479 3480
	*ref_key++= get_store_key(thd,
				  keyuse,join->const_table_map,
				  &keyinfo->key_part[i],
				  (char*) key_buff,maybe_null);
3481
      /*
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3482
	Remeber if we are going to use REF_OR_NULL
3483 3484 3485
	But only if field _really_ can be null i.e. we force JT_REF
	instead of JT_REF_OR_NULL in case if field can't be null
      */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3486
      if ((keyuse->optimize & KEY_OPTIMIZE_REF_OR_NULL) && maybe_null)
3487
	null_ref_key= key_buff;
3488
      key_buff+=keyinfo->key_part[i].store_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3489
    }
3490 3491
  } /* not ftkey */
  *ref_key=0;				// end_marker
3492 3493 3494 3495
  if (j->type == JT_FT)
    return 0;
  if (j->type == JT_CONST)
    j->table->const_table= 1;
3496
  else if (((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY |
monty@mysql.com's avatar
monty@mysql.com committed
3497
			       HA_END_SPACE_KEY)) != HA_NOSAME) ||
monty@mysql.com's avatar
monty@mysql.com committed
3498
	   keyparts != keyinfo->key_parts || null_ref_key)
3499 3500 3501
  {
    /* Must read with repeat */
    j->type= null_ref_key ? JT_REF_OR_NULL : JT_REF;
3502
    j->ref.null_ref_key= null_ref_key;
3503
  }
sergefp@mysql.com's avatar
sergefp@mysql.com committed
3504
  else if (keyuse_uses_no_tables)
3505
  {
3506 3507 3508 3509 3510 3511 3512 3513
    /*
      This happen if we are using a constant expression in the ON part
      of an LEFT JOIN.
      SELECT * FROM a LEFT JOIN b ON b.key=30
      Here we should not mark the table as a 'const' as a field may
      have a 'normal' value or a NULL value.
    */
    j->type=JT_CONST;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3514
  }
3515 3516
  else
    j->type=JT_EQ_REF;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3517 3518 3519 3520
  return 0;
}


3521

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3522
static store_key *
3523 3524
get_store_key(THD *thd, KEYUSE *keyuse, table_map used_tables,
	      KEY_PART_INFO *key_part, char *key_buff, uint maybe_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3525 3526 3527
{
  if (!((~used_tables) & keyuse->used_tables))		// if const item
  {
3528 3529
    return new store_key_const_item(thd,
				    key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3530 3531 3532 3533 3534 3535
				    key_buff + maybe_null,
				    maybe_null ? key_buff : 0,
				    key_part->length,
				    keyuse->val);
  }
  else if (keyuse->val->type() == Item::FIELD_ITEM)
3536 3537
    return new store_key_field(thd,
			       key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3538 3539 3540 3541 3542
			       key_buff + maybe_null,
			       maybe_null ? key_buff : 0,
			       key_part->length,
			       ((Item_field*) keyuse->val)->field,
			       keyuse->val->full_name());
3543 3544
  return new store_key_item(thd,
			    key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3545 3546 3547 3548 3549 3550 3551
			    key_buff + maybe_null,
			    maybe_null ? key_buff : 0,
			    key_part->length,
			    keyuse->val);
}

/*
3552 3553
  This function is only called for const items on fields which are keys
  returns 1 if there was some conversion made when the field was stored.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3554 3555 3556
*/

bool
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
3557
store_val_in_field(Field *field, Item *item, enum_check_fields check_flag)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3558
{
3559
  bool error;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3560
  THD *thd=current_thd;
3561
  ha_rows cuted_fields=thd->cuted_fields;
3562 3563 3564 3565 3566
  /*
    we should restore old value of count_cuted_fields because
    store_val_in_field can be called from mysql_insert 
    with select_insert, which make count_cuted_fields= 1
   */
monty@mysql.com's avatar
monty@mysql.com committed
3567
  enum_check_fields old_count_cuted_fields= thd->count_cuted_fields;
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
3568
  thd->count_cuted_fields= check_flag;
3569
  error= item->save_in_field(field, 1);
3570
  thd->count_cuted_fields= old_count_cuted_fields;
3571
  return error || cuted_fields != thd->cuted_fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3572 3573 3574 3575 3576 3577 3578 3579 3580
}


static bool
make_simple_join(JOIN *join,TABLE *tmp_table)
{
  TABLE **tableptr;
  JOIN_TAB *join_tab;

3581 3582
  if (!(tableptr=(TABLE**) join->thd->alloc(sizeof(TABLE*))) ||
      !(join_tab=(JOIN_TAB*) join->thd->alloc(sizeof(JOIN_TAB))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3583 3584 3585 3586 3587 3588
    return TRUE;
  join->join_tab=join_tab;
  join->table=tableptr; tableptr[0]=tmp_table;
  join->tables=1;
  join->const_tables=0;
  join->const_table_map=0;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
3589 3590 3591
  join->tmp_table_param.field_count= join->tmp_table_param.sum_func_count=
    join->tmp_table_param.func_count=0;
  join->tmp_table_param.copy_field=join->tmp_table_param.copy_field_end=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3592
  join->first_record=join->sort_and_group=0;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
3593
  join->send_records=(ha_rows) 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3594
  join->group=0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3595
  join->row_limit=join->unit->select_limit_cnt;
3596
  join->do_send_rows = (join->row_limit) ? 1 : 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3597

serg@serg.mylan's avatar
serg@serg.mylan committed
3598
  join_tab->cache.buff=0;			/* No caching */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3599 3600 3601 3602 3603
  join_tab->table=tmp_table;
  join_tab->select=0;
  join_tab->select_cond=0;
  join_tab->quick=0;
  join_tab->type= JT_ALL;			/* Map through all records */
3604 3605
  join_tab->keys.init();
  join_tab->keys.set_all();                     /* test everything in quick */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3606 3607 3608
  join_tab->info=0;
  join_tab->on_expr=0;
  join_tab->ref.key = -1;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
3609 3610
  join_tab->not_used_in_distinct=0;
  join_tab->read_first_record= join_init_read_record;
3611
  join_tab->join=join;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
3612
  bzero((char*) &join_tab->read_record,sizeof(join_tab->read_record));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3613 3614 3615 3616 3617 3618
  tmp_table->status=0;
  tmp_table->null_row=0;
  return FALSE;
}


3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657
inline void add_cond_and_fix(Item **e1, Item *e2)
{
  if (*e1)
  {
    Item *res;
    if ((res= new Item_cond_and(*e1, e2)))
    {
      *e1= res;
      res->quick_fix_field();
    }
  }
  else
    *e1= e2;
}


/*
  Add to join_tab->select_cond[i] "table.field IS NOT NULL" conditions we've
  inferred from ref/eq_ref access performed.

  SYNOPSIS
    add_not_null_conds()
      join  Join to process

  NOTES
    This function is a part of "Early NULL-values filtering for ref access"
    optimization.

    Example of this optimization:
      For query SELECT * FROM t1,t2 WHERE t2.key=t1.field
      and plan " any-access(t1), ref(t2.key=t1.field) "
      add "t1.field IS NOT NULL" to t1's table condition.
    Description of the optimization:
    
      We look through equalities choosen to perform ref/eq_ref access,
      pick equalities that have form "tbl.part_of_key = othertbl.field"
      (where othertbl is a non-const table and othertbl.field may be NULL)
      and add them to conditions on correspoding tables (othertbl in this
      example).
3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674

      Exception from that is the case when referred_tab->join != join.
      I.e. don't add NOT NULL constraints from any embedded subquery.
      Consider this query:
      SELECT A.f2 FROM t1 LEFT JOIN t2 A ON A.f2 = f1
      WHERE A.f3=(SELECT MIN(f3) FROM  t2 C WHERE A.f4 = C.f4) OR A.f3 IS NULL;
      Here condition A.f3 IS NOT NULL is going to be added to the WHERE
      condition of the embedding query.
      Another example:
      SELECT * FROM t10, t11 WHERE (t10.a < 10 OR t10.a IS NULL)
      AND t11.b <=> t10.b AND (t11.a = (SELECT MAX(a) FROM t12
      WHERE t12.b = t10.a ));
      Here condition t10.a IS NOT NULL is going to be added.
      In both cases addition of NOT NULL condition will erroneously reject
      some rows of the result set.
      referred_tab->join != join constraint would disallow such additions.

3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701
      This optimization doesn't affect the choices that ref, range, or join
      optimizer make. This was intentional because this was added after 4.1
      was GA.
      
    Implementation overview
      1. update_ref_and_keys() accumulates info about null-rejecting
         predicates in in KEY_FIELD::null_rejecting
      1.1 add_key_part saves these to KEYUSE.
      2. create_ref_for_key copies them to TABLE_REF.
      3. add_not_null_conds adds "x IS NOT NULL" to join_tab->select_cond of
         appropiate JOIN_TAB members.
*/

static void add_not_null_conds(JOIN *join)
{
  DBUG_ENTER("add_not_null_conds");
  for (uint i=join->const_tables ; i < join->tables ; i++)
  {
    JOIN_TAB *tab=join->join_tab+i;
    if ((tab->type == JT_REF || tab->type == JT_REF_OR_NULL) &&
         !tab->table->maybe_null)
    {
      for (uint keypart= 0; keypart < tab->ref.key_parts; keypart++)
      {
        if (tab->ref.null_rejecting & (1 << keypart))
        {
          Item *item= tab->ref.items[keypart];
3702
          Item *notnull;
3703 3704 3705
          DBUG_ASSERT(item->type() == Item::FIELD_ITEM);
          Item_field *not_null_item= (Item_field*)item;
          JOIN_TAB *referred_tab= not_null_item->field->table->reginfo.join_tab;
3706 3707 3708 3709 3710 3711
          /*
            For UPDATE queries such as:
            UPDATE t1 SET t1.f2=(SELECT MAX(t2.f4) FROM t2 WHERE t2.f3=t1.f1);
            not_null_item is the t1.f1, but it's referred_tab is 0.
          */
          if (!referred_tab || referred_tab->join != join)
3712
            continue;
3713
          if (!(notnull= new Item_func_isnotnull(not_null_item)))
3714
            DBUG_VOID_RETURN;
3715 3716 3717 3718 3719 3720 3721 3722
          /*
            We need to do full fix_fields() call here in order to have correct
            notnull->const_item(). This is needed e.g. by test_quick_select 
            when it is called from make_join_select after this function is 
            called.
          */
          if (notnull->fix_fields(join->thd, join->tables_list, &notnull))
            DBUG_VOID_RETURN;
3723
          DBUG_EXECUTE("where",print_where(notnull,
3724
                                           referred_tab->table->table_name););
3725
          add_cond_and_fix(&referred_tab->select_cond, notnull);
3726 3727 3728 3729 3730 3731 3732
        }
      }
    }
  }
  DBUG_VOID_RETURN;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3733 3734 3735 3736 3737 3738
static bool
make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
{
  DBUG_ENTER("make_join_select");
  if (select)
  {
3739
    add_not_null_conds(join);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3740 3741 3742
    table_map used_tables;
    if (join->tables > 1)
      cond->update_used_tables();		// Tablenr may have changed
3743 3744 3745
    if (join->const_tables == join->tables &&
	join->thd->lex->current_select->master_unit() ==
	&join->thd->lex->unit)		// not upper level SELECT
3746
      join->const_table_map|=RAND_TABLE_BIT;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3747 3748 3749 3750 3751
    {						// Check const tables
      COND *const_cond=
	make_cond_for_table(cond,join->const_table_map,(table_map) 0);
      DBUG_EXECUTE("where",print_where(const_cond,"constants"););
      if (const_cond && !const_cond->val_int())
3752 3753
      {
	DBUG_PRINT("info",("Found impossible WHERE condition"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3754
	DBUG_RETURN(1);				// Impossible const condition
3755
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3756
    }
3757 3758
    used_tables=((select->const_tables=join->const_table_map) |
		 OUTER_REF_TABLE_BIT | RAND_TABLE_BIT);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3759 3760 3761 3762
    for (uint i=join->const_tables ; i < join->tables ; i++)
    {
      JOIN_TAB *tab=join->join_tab+i;
      table_map current_map= tab->table->map;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3763 3764 3765 3766
      /*
	Following force including random expression in last table condition.
	It solve problem with select like SELECT * FROM t1 WHERE rand() > 0.5
      */
3767
      if (i == join->tables-1)
3768
	current_map|= OUTER_REF_TABLE_BIT | RAND_TABLE_BIT;
3769
      bool use_quick_range=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3770
      used_tables|=current_map;
3771 3772

      if (tab->type == JT_REF && tab->quick &&
3773
	  (uint) tab->ref.key == tab->quick->index &&
3774 3775 3776 3777 3778 3779
	  tab->ref.key_length < tab->quick->max_used_key_length)
      {
	/* Range uses longer key;  Use this instead of ref on key */
	tab->type=JT_ALL;
	use_quick_range=1;
	tab->use_quick=1;
3780
        tab->ref.key= -1;
3781
	tab->ref.key_parts=0;		// Don't use ref key.
3782
	join->best_positions[i].records_read= rows2double(tab->quick->records);
3783 3784
      }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3785
      COND *tmp=make_cond_for_table(cond,used_tables,current_map);
3786 3787 3788 3789 3790 3791 3792 3793
      if (!tmp && tab->quick)
      {						// Outer join
	/*
	  Hack to handle the case where we only refer to a table
	  in the ON part of an OUTER JOIN.
	*/
	tmp=new Item_int((longlong) 1,1);	// Always true
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3794 3795 3796
      if (tmp)
      {
	SQL_SELECT *sel=tab->select=(SQL_SELECT*)
3797
	  join->thd->memdup((gptr) select, sizeof(SQL_SELECT));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3798 3799
	if (!sel)
	  DBUG_RETURN(1);			// End of memory
3800 3801
        add_cond_and_fix(&tab->select_cond, tmp);
        sel->cond= tab->select_cond;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3802
	sel->head=tab->table;
3803
	DBUG_EXECUTE("where",print_where(tmp,tab->table->table_name););
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3804 3805
	if (tab->quick)
	{
3806 3807
	  /* Use quick key read if it's a constant and it's not used
	     with key reading */
3808
	  if (tab->needed_reg.is_clear_all() && tab->type != JT_EQ_REF
3809
	      && tab->type != JT_FT && (tab->type != JT_REF ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3810 3811 3812
	       (uint) tab->ref.key == tab->quick->index))
	  {
	    sel->quick=tab->quick;		// Use value from get_quick_...
3813 3814
	    sel->quick_keys.clear_all();
	    sel->needed_reg.clear_all();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3815 3816 3817 3818 3819 3820 3821 3822 3823 3824
	  }
	  else
	  {
	    delete tab->quick;
	  }
	  tab->quick=0;
	}
	uint ref_key=(uint) sel->head->reginfo.join_tab->ref.key+1;
	if (i == join->const_tables && ref_key)
	{
3825 3826
	  if (!tab->const_keys.is_clear_all() &&
              tab->table->reginfo.impossible_range)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3827 3828
	    DBUG_RETURN(1);
	}
3829
	else if (tab->type == JT_ALL && ! use_quick_range)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3830
	{
3831
	  if (!tab->const_keys.is_clear_all() &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3832 3833 3834 3835
	      tab->table->reginfo.impossible_range)
	    DBUG_RETURN(1);				// Impossible range
	  /*
	    We plan to scan all rows.
3836 3837 3838
	    Check again if we should use an index.
	    We could have used an column from a previous table in
	    the index if we are using limit and this is the first table
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3839 3840
	  */

3841 3842 3843
	  if ((!tab->keys.is_subset(tab->const_keys) && i > 0) ||
	      (!tab->const_keys.is_clear_all() && i == join->const_tables &&
	       join->unit->select_limit_cnt <
3844
	       join->best_positions[i].records_read &&
3845
	       !(join->select_options & OPTION_FOUND_ROWS)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3846
	  {
3847 3848
	    /* Join with outer join condition */
	    COND *orig_cond=sel->cond;
3849
	    sel->cond= and_conds(sel->cond, tab->on_expr);
3850 3851 3852 3853 3854 3855 3856 3857

	    /*
              We can't call sel->cond->fix_fields,
              as it will break tab->on_expr if it's AND condition
              (fix_fields currently removes extra AND/OR levels).
              Yet attributes of the just built condition are not needed.
              Thus we call sel->cond->quick_fix_field for safety.
	    */
3858
	    if (sel->cond && !sel->cond->fixed)
3859 3860
	      sel->cond->quick_fix_field();

3861
	    if (sel->test_quick_select(join->thd, tab->keys,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3862
				       used_tables & ~ current_map,
3863 3864 3865
				       (join->select_options &
					OPTION_FOUND_ROWS ?
					HA_POS_ERROR :
3866
					join->unit->select_limit_cnt), 0) < 0)
3867 3868 3869 3870 3871
            {
	      /*
		Before reporting "Impossible WHERE" for the whole query
		we have to check isn't it only "impossible ON" instead
	      */
3872 3873
              sel->cond=orig_cond;
              if (!tab->on_expr ||
3874
                  sel->test_quick_select(join->thd, tab->keys,
3875 3876 3877 3878
                                         used_tables & ~ current_map,
                                         (join->select_options &
                                          OPTION_FOUND_ROWS ?
                                          HA_POS_ERROR :
3879
                                          join->unit->select_limit_cnt),0) < 0)
3880
		DBUG_RETURN(1);			// Impossible WHERE
3881 3882 3883 3884
            }
            else
	      sel->cond=orig_cond;

3885 3886 3887
	    /* Fix for EXPLAIN */
	    if (sel->quick)
	      join->best_positions[i].records_read= sel->quick->records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3888 3889 3890 3891
	  }
	  else
	  {
	    sel->needed_reg=tab->needed_reg;
3892
	    sel->quick_keys.clear_all();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3893
	  }
3894 3895
	  if (!sel->quick_keys.is_subset(tab->checked_keys) ||
              !sel->needed_reg.is_subset(tab->checked_keys))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3896
	  {
3897 3898 3899 3900
	    tab->keys=sel->quick_keys;
            tab->keys.merge(sel->needed_reg);
	    tab->use_quick= (!sel->needed_reg.is_clear_all() &&
			     (select->quick_keys.is_clear_all() ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3901 3902 3903
			      (select->quick &&
			       (select->quick->records >= 100L)))) ?
	      2 : 1;
hf@deer.(none)'s avatar
hf@deer.(none) committed
3904
	    sel->read_tables= used_tables & ~current_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3905 3906 3907 3908 3909 3910 3911 3912 3913
	  }
	  if (i != join->const_tables && tab->use_quick != 2)
	  {					/* Read with cache */
	    if ((tmp=make_cond_for_table(cond,
					 join->const_table_map |
					 current_map,
					 current_map)))
	    {
	      DBUG_EXECUTE("where",print_where(tmp,"cache"););
3914 3915
	      tab->cache.select=(SQL_SELECT*)
		join->thd->memdup((gptr) sel, sizeof(SQL_SELECT));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928
	      tab->cache.select->cond=tmp;
	      tab->cache.select->read_tables=join->const_table_map;
	    }
	  }
	}
      }
    }
  }
  DBUG_RETURN(0);
}


static void
3929
make_join_readinfo(JOIN *join, uint options)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3930 3931
{
  uint i;
3932
  bool statistics= test(!(join->select_options & SELECT_DESCRIBE));
3933
  bool ordered_set= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3934 3935 3936 3937 3938 3939 3940 3941 3942
  DBUG_ENTER("make_join_readinfo");

  for (i=join->const_tables ; i < join->tables ; i++)
  {
    JOIN_TAB *tab=join->join_tab+i;
    TABLE *table=tab->table;
    tab->read_record.table= table;
    tab->read_record.file=table->file;
    tab->next_select=sub_select;		/* normal select */
3943 3944 3945 3946 3947 3948

    /*
      Determine if the set is already ordered for ORDER BY, so it can 
      disable join cache because it will change the ordering of the results.
      Code handles sort table that is at any location (not only first after 
      the const tables) despite the fact that it's currently prohibited.
3949 3950 3951
      We must disable join cache if the first non-const table alone is
      ordered. If there is a temp table the ordering is done as a last
      operation and doesn't prevent join cache usage.
3952
    */
3953 3954
    if (!ordered_set && !join->need_tmp &&
        ((table == join->sort_by_table &&
3955 3956 3957 3958
         (!join->order || join->skip_sort_order ||
          test_if_skip_sort_order(tab, join->order, join->select_limit,
                                  1))
        ) ||
3959
        (join->sort_by_table == (TABLE *) 1 && i != join->const_tables)))
3960 3961
      ordered_set= 1;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3962 3963 3964 3965 3966 3967 3968 3969 3970 3971
    switch (tab->type) {
    case JT_SYSTEM:				// Only happens with left join
      table->status=STATUS_NO_RECORD;
      tab->read_first_record= join_read_system;
      tab->read_record.read_record= join_no_more_records;
      break;
    case JT_CONST:				// Only happens with left join
      table->status=STATUS_NO_RECORD;
      tab->read_first_record= join_read_const;
      tab->read_record.read_record= join_no_more_records;
3972
      if (table->used_keys.is_set(tab->ref.key) &&
3973 3974 3975 3976 3977
          !table->no_keyread)
      {
        table->key_read=1;
        table->file->extra(HA_EXTRA_KEYREAD);
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3978 3979 3980
      break;
    case JT_EQ_REF:
      table->status=STATUS_NO_RECORD;
3981 3982 3983 3984 3985
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3986 3987 3988 3989
      delete tab->quick;
      tab->quick=0;
      tab->read_first_record= join_read_key;
      tab->read_record.read_record= join_no_more_records;
3990
      if (table->used_keys.is_set(tab->ref.key) &&
3991
	  !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3992 3993 3994 3995 3996
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
      break;
3997
    case JT_REF_OR_NULL:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3998 3999
    case JT_REF:
      table->status=STATUS_NO_RECORD;
4000 4001 4002 4003 4004
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4005 4006
      delete tab->quick;
      tab->quick=0;
4007
      if (table->used_keys.is_set(tab->ref.key) &&
4008
	  !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4009 4010 4011 4012
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
4013 4014 4015 4016 4017 4018 4019 4020 4021 4022
      if (tab->type == JT_REF)
      {
	tab->read_first_record= join_read_always_key;
	tab->read_record.read_record= join_read_next_same;
      }
      else
      {
	tab->read_first_record= join_read_always_key_or_null;
	tab->read_record.read_record= join_read_next_same_or_null;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4023 4024 4025 4026 4027 4028 4029 4030
      break;
    case JT_FT:
      table->status=STATUS_NO_RECORD;
      tab->read_first_record= join_ft_read_first;
      tab->read_record.read_record= join_ft_read_next;
      break;
    case JT_ALL:
      /*
4031
	If previous table use cache
4032
        If the incoming data set is already sorted don't use cache.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4033 4034
      */
      table->status=STATUS_NO_RECORD;
4035
      if (i != join->const_tables && !(options & SELECT_NO_JOIN_CACHE) &&
4036
	  tab->use_quick != 2 && !tab->on_expr && !ordered_set)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4037 4038 4039 4040 4041 4042 4043 4044 4045 4046
      {
	if ((options & SELECT_DESCRIBE) ||
	    !join_init_cache(join->thd,join->join_tab+join->const_tables,
			     i-join->const_tables))
	{
	  tab[-1].next_select=sub_select_cache; /* Patch previous */
	}
      }
      /* These init changes read_record */
      if (tab->use_quick == 2)
4047
      {
4048
	join->thd->server_status|=SERVER_QUERY_NO_GOOD_INDEX_USED;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4049
	tab->read_first_record= join_init_quick_read_record;
4050 4051
	if (statistics)
	  statistic_increment(select_range_check_count, &LOCK_status);
4052
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4053 4054 4055
      else
      {
	tab->read_first_record= join_init_read_record;
4056 4057 4058 4059
	if (i == join->const_tables)
	{
	  if (tab->select && tab->select->quick)
	  {
4060 4061
	    if (statistics)
	      statistic_increment(select_range_count, &LOCK_status);
4062 4063 4064
	  }
	  else
	  {
4065
	    join->thd->server_status|=SERVER_QUERY_NO_INDEX_USED;
4066 4067
	    if (statistics)
	      statistic_increment(select_scan_count, &LOCK_status);
4068 4069 4070 4071 4072 4073
	  }
	}
	else
	{
	  if (tab->select && tab->select->quick)
	  {
4074 4075
	    if (statistics)
	      statistic_increment(select_full_range_join_count, &LOCK_status);
4076 4077 4078
	  }
	  else
	  {
4079
	    join->thd->server_status|=SERVER_QUERY_NO_INDEX_USED;
4080 4081
	    if (statistics)
	      statistic_increment(select_full_join_count, &LOCK_status);
4082 4083
	  }
	}
4084
	if (!table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4085
	{
4086
	  if (tab->select && tab->select->quick &&
4087
	      table->used_keys.is_set(tab->select->quick->index))
4088 4089 4090 4091
	  {
	    table->key_read=1;
	    table->file->extra(HA_EXTRA_KEYREAD);
	  }
4092 4093
	  else if (!table->used_keys.is_clear_all() &&
		   !(tab->select && tab->select->quick))
4094
	  {					// Only read index tree
serg@serg.mylan's avatar
serg@serg.mylan committed
4095
	    tab->index=find_shortest_key(table, & table->used_keys);
4096
	    tab->read_first_record= join_read_first;
4097 4098
	    tab->type=JT_NEXT;		// Read with index_first / index_next
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114
	}
      }
      break;
    default:
      DBUG_PRINT("error",("Table type %d found",tab->type)); /* purecov: deadcode */
      break;					/* purecov: deadcode */
    case JT_UNKNOWN:
    case JT_MAYBE_REF:
      abort();					/* purecov: deadcode */
    }
  }
  join->join_tab[join->tables-1].next_select=0; /* Set by do_select */
  DBUG_VOID_RETURN;
}


4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136
/*
  Give error if we some tables are done with a full join

  SYNOPSIS
    error_if_full_join()
    join		Join condition

  USAGE
   This is used by multi_table_update and multi_table_delete when running
   in safe mode

 RETURN VALUES
   0	ok
   1	Error (full join used)
*/

bool error_if_full_join(JOIN *join)
{
  for (JOIN_TAB *tab=join->join_tab, *end=join->join_tab+join->tables;
       tab < end;
       tab++)
  {
4137
    if (tab->type == JT_ALL && (!tab->select || !tab->select->quick))
4138 4139 4140 4141 4142 4143 4144 4145 4146
    {
      my_error(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE,MYF(0));
      return(1);
    }
  }
  return(0);
}


4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168
/*
  cleanup JOIN_TAB

  SYNOPSIS
    JOIN_TAB::cleanup()
*/

void JOIN_TAB::cleanup()
{
  delete select;
  select= 0;
  delete quick;
  quick= 0;
  x_free(cache.buff);
  cache.buff= 0;
  if (table)
  {
    if (table->key_read)
    {
      table->key_read= 0;
      table->file->extra(HA_EXTRA_NO_KEYREAD);
    }
4169
    table->file->ha_index_or_rnd_end();
4170 4171 4172 4173 4174 4175 4176 4177 4178 4179
    /*
      We need to reset this for next select
      (Tested in part_of_refkey)
    */
    table->reginfo.join_tab= 0;
  }
  end_read_record(&read_record);
}


4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192
/*
  Free resources of given join

  SYNOPSIS
    JOIN::join_free()
    fill - true if we should free all resources, call with full==1 should be
           last, before it this function can be called with full==0

  NOTE: with subquery this function definitely will be called several times,
    but even for simple query it can be called several times.
*/
void
JOIN::join_free(bool full)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4193 4194
{
  JOIN_TAB *tab,*end;
4195
  DBUG_ENTER("JOIN::join_free");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4196

4197
  full= full || (!select_lex->uncacheable &&
4198
                 !thd->lex->subqueries &&
4199
                 !thd->lex->describe); // do not cleanup too early on EXPLAIN
4200

4201
  if (table)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4202
  {
4203 4204 4205 4206
    /*
      Only a sorted table may be cached.  This sorted table is always the
      first non const table in join->table
    */
4207
    if (tables > const_tables) // Test for not-const tables
4208
    {
4209 4210
      free_io_cache(table[const_tables]);
      filesort_free_buffers(table[const_tables]);
4211
    }
4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223

    for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit(); unit;
         unit= unit->next_unit())
    {
      JOIN *join;
      for (SELECT_LEX *sl= unit->first_select_in_union(); sl;
           sl= sl->next_select())
        if ((join= sl->join))
          join->join_free(full);
    }

    if (full)
4224 4225 4226 4227
    {
      for (tab= join_tab, end= tab+tables; tab != end; tab++)
	tab->cleanup();
      table= 0;
4228
      tables= 0;
4229 4230
    }
    else
4231
    {
4232
      for (tab= join_tab, end= tab+tables; tab != end; tab++)
4233
      {
4234 4235
	if (tab->table)
	    tab->table->file->ha_index_or_rnd_end();
4236
      }
4237
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4238
  }
4239

4240 4241 4242 4243
  /*
    We are not using tables anymore
    Unlock all tables. We may be in an INSERT .... SELECT statement.
  */
serg@serg.mylan's avatar
serg@serg.mylan committed
4244
  if (full && lock && thd->lock && !(select_options & SELECT_NO_UNLOCK) &&
4245
      !select_lex->subquery_in_having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4246
  {
4247 4248 4249 4250 4251 4252 4253
    // TODO: unlock tables even if the join isn't top level select in the tree
    if (select_lex == (thd->lex->unit.fake_select_lex ?
                       thd->lex->unit.fake_select_lex : &thd->lex->select_lex))
    {
      mysql_unlock_read_tables(thd, lock);        // Don't free join->lock
      lock=0;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4254
  }
4255

4256 4257
  if (full)
  {
4258
    group_fields.delete_elements();
4259 4260 4261 4262 4263
    /*
      We can't call delete_elements() on copy_funcs as this will cause
      problems in free_elements() as some of the elements are then deleted.
    */
    tmp_table_param.copy_funcs.empty();
4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277
    /*
      If we have tmp_join and 'this' JOIN is not tmp_join and
      tmp_table_param.copy_field's  of them are equal then we have to remove
      pointer to  tmp_table_param.copy_field from tmp_join, because it qill
      be removed in tmp_table_param.cleanup().
    */
    if (tmp_join &&
        tmp_join != this &&
        tmp_join->tmp_table_param.copy_field ==
        tmp_table_param.copy_field)
    {
      tmp_join->tmp_table_param.copy_field=
        tmp_join->tmp_table_param.save_copy_field= 0;
    }
4278
    tmp_table_param.cleanup();
4279
  }
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
4280
  DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4281 4282 4283 4284
}


/*****************************************************************************
4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297
  Remove the following expressions from ORDER BY and GROUP BY:
  Constant expressions
  Expression that only uses tables that are of type EQ_REF and the reference
  is in the ORDER list or if all refereed tables are of the above type.

  In the following, the X field can be removed:
  SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t1.a,t2.X
  SELECT * FROM t1,t2,t3 WHERE t1.a=t2.a AND t2.b=t3.b ORDER BY t1.a,t3.X

  These can't be optimized:
  SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t2.X,t1.a
  SELECT * FROM t1,t2 WHERE t1.a=t2.a AND t1.b=t2.b ORDER BY t1.a,t2.c
  SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t2.b,t1.a
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4298 4299 4300 4301 4302 4303 4304 4305 4306 4307
*****************************************************************************/

static bool
eq_ref_table(JOIN *join, ORDER *start_order, JOIN_TAB *tab)
{
  if (tab->cached_eq_ref_table)			// If cached
    return tab->eq_ref_table;
  tab->cached_eq_ref_table=1;
  if (tab->type == JT_CONST)			// We can skip const tables
    return (tab->eq_ref_table=1);		/* purecov: inspected */
4308
  if (tab->type != JT_EQ_REF || tab->table->maybe_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321
    return (tab->eq_ref_table=0);		// We must use this
  Item **ref_item=tab->ref.items;
  Item **end=ref_item+tab->ref.key_parts;
  uint found=0;
  table_map map=tab->table->map;

  for (; ref_item != end ; ref_item++)
  {
    if (! (*ref_item)->const_item())
    {						// Not a const ref
      ORDER *order;
      for (order=start_order ; order ; order=order->next)
      {
4322
	if ((*ref_item)->eq(order->item[0],0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4323 4324 4325 4326 4327
	  break;
      }
      if (order)
      {
	found++;
monty@bitch.mysql.fi's avatar
monty@bitch.mysql.fi committed
4328
	DBUG_ASSERT(!(order->used & map));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4329 4330 4331 4332 4333 4334 4335 4336
	order->used|=map;
	continue;				// Used in ORDER BY
      }
      if (!only_eq_ref_tables(join,start_order, (*ref_item)->used_tables()))
	return (tab->eq_ref_table=0);
    }
  }
  /* Check that there was no reference to table before sort order */
4337
  for (; found && start_order ; start_order=start_order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354
  {
    if (start_order->used & map)
    {
      found--;
      continue;
    }
    if (start_order->depend_map & map)
      return (tab->eq_ref_table=0);
  }
  return tab->eq_ref_table=1;
}


static bool
only_eq_ref_tables(JOIN *join,ORDER *order,table_map tables)
{
  if (specialflag &  SPECIAL_SAFE_MODE)
4355
    return 0;			// skip this optimize /* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370
  for (JOIN_TAB **tab=join->map2table ; tables ; tab++, tables>>=1)
  {
    if (tables & 1 && !eq_ref_table(join, order, *tab))
      return 0;
  }
  return 1;
}


/* Update the dependency map for the tables */

static void update_depend_map(JOIN *join)
{
  JOIN_TAB *join_tab=join->join_tab, *end=join_tab+join->tables;

4371
  for (; join_tab != end ; join_tab++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4372 4373 4374 4375 4376 4377 4378
  {
    TABLE_REF *ref= &join_tab->ref;
    table_map depend_map=0;
    Item **item=ref->items;
    uint i;
    for (i=0 ; i < ref->key_parts ; i++,item++)
      depend_map|=(*item)->used_tables();
4379
    ref->depend_map=depend_map & ~OUTER_REF_TABLE_BIT;
4380
    depend_map&= ~OUTER_REF_TABLE_BIT;
4381
    for (JOIN_TAB **tab=join->map2table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4382
	 depend_map ;
4383
	 tab++,depend_map>>=1 )
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4384 4385
    {
      if (depend_map & 1)
4386
	ref->depend_map|=(*tab)->ref.depend_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4387 4388 4389 4390 4391 4392 4393 4394 4395
    }
  }
}


/* Update the dependency map for the sort order */

static void update_depend_map(JOIN *join, ORDER *order)
{
4396
  for (; order ; order=order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4397 4398 4399 4400
  {
    table_map depend_map;
    order->item[0]->update_used_tables();
    order->depend_map=depend_map=order->item[0]->used_tables();
4401 4402
    // Not item_sum(), RAND() and no reference to table outside of sub select
    if (!(order->depend_map & (OUTER_REF_TABLE_BIT | RAND_TABLE_BIT)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4403
    {
4404
      for (JOIN_TAB **tab=join->map2table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4405
	   depend_map ;
4406
	   tab++, depend_map>>=1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4407 4408
      {
	if (depend_map & 1)
4409
	  order->depend_map|=(*tab)->ref.depend_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4410 4411 4412 4413 4414 4415 4416
      }
    }
  }
}


/*
4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434
  Remove all constants and check if ORDER only contains simple expressions

  SYNOPSIS
   remove_const()
   join			Join handler
   first_order		List of SORT or GROUP order
   cond			WHERE statement
   change_list		Set to 1 if we should remove things from list
			If this is not set, then only simple_order is
                        calculated   
   simple_order		Set to 1 if we are only using simple expressions

  RETURN
    Returns new sort order

    simple_order is set to 1 if sort_order only uses fields from head table
    and the head table is not a LEFT JOIN table

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4435 4436 4437
*/

static ORDER *
4438 4439
remove_const(JOIN *join,ORDER *first_order, COND *cond,
             bool change_list, bool *simple_order)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4440 4441
{
  if (join->tables == join->const_tables)
4442 4443
    return change_list ? 0 : first_order;		// No need to sort

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4444 4445 4446 4447
  ORDER *order,**prev_ptr;
  table_map first_table= join->join_tab[join->const_tables].table->map;
  table_map not_const_tables= ~join->const_table_map;
  table_map ref;
4448 4449
  DBUG_ENTER("remove_const");

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462
  prev_ptr= &first_order;
  *simple_order= join->join_tab[join->const_tables].on_expr ? 0 : 1;

  /* NOTE: A variable of not_const_tables ^ first_table; breaks gcc 2.7 */

  update_depend_map(join, first_order);
  for (order=first_order; order ; order=order->next)
  {
    table_map order_tables=order->item[0]->used_tables();
    if (order->item[0]->with_sum_func)
      *simple_order=0;				// Must do a temp table to sort
    else if (!(order_tables & not_const_tables))
    {
igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
4463 4464
      if (order->item[0]->with_subselect)
        order->item[0]->val_str(&order->item[0]->str_value);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4465
      DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
4466
      continue;					// skip const item
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4467 4468 4469
    }
    else
    {
4470
      if (order_tables & (RAND_TABLE_BIT | OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481
	*simple_order=0;
      else
      {
	Item *comp_item=0;
	if (cond && const_expression_in_where(cond,order->item[0], &comp_item))
	{
	  DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
	  continue;
	}
	if ((ref=order_tables & (not_const_tables ^ first_table)))
	{
4482 4483
	  if (!(order_tables & first_table) &&
              only_eq_ref_tables(join,first_order, ref))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4484 4485 4486 4487 4488 4489 4490 4491
	  {
	    DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
	    continue;
	  }
	  *simple_order=0;			// Must do a temp table to sort
	}
      }
    }
4492 4493
    if (change_list)
      *prev_ptr= order;				// use this entry
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4494 4495
    prev_ptr= &order->next;
  }
4496 4497 4498
  if (change_list)
    *prev_ptr=0;
  if (prev_ptr == &first_order)			// Nothing to sort/group
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4499 4500 4501 4502 4503
    *simple_order=1;
  DBUG_PRINT("exit",("simple_order: %d",(int) *simple_order));
  DBUG_RETURN(first_order);
}

4504

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4505
static int
4506 4507
return_zero_rows(JOIN *join, select_result *result,TABLE_LIST *tables,
		 List<Item> &fields, bool send_row, uint select_options,
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
4508 4509
		 const char *info, Item *having, Procedure *procedure,
		 SELECT_LEX_UNIT *unit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4510 4511 4512 4513
{
  DBUG_ENTER("return_zero_rows");

  if (select_options & SELECT_DESCRIBE)
4514
  {
monty@mysql.com's avatar
monty@mysql.com committed
4515
    select_describe(join, FALSE, FALSE, FALSE, info);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4516 4517
    DBUG_RETURN(0);
  }
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
4518

4519 4520
  join->join_free(0);

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4521 4522 4523 4524
  if (send_row)
  {
    for (TABLE_LIST *table=tables; table ; table=table->next)
      mark_as_null_row(table->table);		// All fields are NULL
4525
    if (having && having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4526 4527
      send_row=0;
  }
4528
  if (!(result->send_fields(fields,1)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4529 4530
  {
    if (send_row)
4531 4532 4533 4534 4535
    {
      List_iterator_fast<Item> it(fields);
      Item *item;
      while ((item= it++))
	item->no_rows_in_result();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4536
      result->send_data(fields);
4537
    }
4538
    result->send_eof();				// Should be safe
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4539
  }
4540 4541
  /* Update results for FOUND_ROWS */
  join->thd->limit_found_rows= join->thd->examined_row_count= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4542 4543 4544
  DBUG_RETURN(0);
}

4545 4546 4547
/*
  used only in JOIN::clear
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4548 4549
static void clear_tables(JOIN *join)
{
4550 4551 4552 4553 4554
  /* 
    must clear only the non-const tables, as const tables
    are not re-calculated.
  */
  for (uint i=join->const_tables ; i < join->tables ; i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4555 4556 4557 4558
    mark_as_null_row(join->table[i]);		// All fields are NULL
}

/*****************************************************************************
4559 4560 4561 4562 4563 4564
  Make som simple condition optimization:
  If there is a test 'field = const' change all refs to 'field' to 'const'
  Remove all dummy tests 'item = item', 'const op const'.
  Remove all 'item is NULL', when item can never be null!
  item->marker should be 0 for all items on entry
  Return in cond_value FALSE if condition is impossible (1 = 2)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4565 4566 4567 4568
*****************************************************************************/

class COND_CMP :public ilink {
public:
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
4569
  static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585
  static void operator delete(void *ptr __attribute__((unused)),
			      size_t size __attribute__((unused))) {} /*lint -e715 */

  Item *and_level;
  Item_func *cmp_func;
  COND_CMP(Item *a,Item_func *b) :and_level(a),cmp_func(b) {}
};

#ifdef __GNUC__
template class I_List<COND_CMP>;
template class I_List_iterator<COND_CMP>;
template class List<Item_func_match>;
template class List_iterator<Item_func_match>;
#endif

/*
4586 4587
  change field = field to field = const for each found field = const in the
  and_level
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4588 4589 4590
*/

static void
4591 4592 4593
change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
                         Item *and_father, Item *cond,
                         Item *field, Item *value)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4594 4595 4596 4597 4598 4599 4600 4601
{
  if (cond->type() == Item::COND_ITEM)
  {
    bool and_level= ((Item_cond*) cond)->functype() ==
      Item_func::COND_AND_FUNC;
    List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
    Item *item;
    while ((item=li++))
4602
      change_cond_ref_to_const(thd, save_list,and_level ? cond : item, item,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4603 4604 4605 4606 4607 4608 4609
			       field, value);
    return;
  }
  if (cond->eq_cmp_result() == Item::COND_OK)
    return;					// Not a boolean function

  Item_bool_func2 *func=  (Item_bool_func2*) cond;
4610 4611 4612
  Item **args= func->arguments();
  Item *left_item=  args[0];
  Item *right_item= args[1];
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4613 4614
  Item_func::Functype functype=  func->functype();

4615 4616 4617 4618
  if (right_item->eq(field,0) && left_item != value &&
      (left_item->result_type() != STRING_RESULT ||
       value->result_type() != STRING_RESULT ||
       left_item->collation.collation == value->collation.collation))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4619 4620
  {
    Item *tmp=value->new_item();
4621 4622
    tmp->collation.set(right_item->collation);
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4623 4624
    if (tmp)
    {
4625
      thd->change_item_tree(args + 1, tmp);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4626 4627 4628 4629 4630 4631 4632 4633 4634
      func->update_used_tables();
      if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
	  && and_father != cond && !left_item->const_item())
      {
	cond->marker=1;
	COND_CMP *tmp2;
	if ((tmp2=new COND_CMP(and_father,func)))
	  save_list->push_back(tmp2);
      }
4635
      func->set_cmp_func();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4636 4637
    }
  }
4638 4639 4640 4641
  else if (left_item->eq(field,0) && right_item != value &&
           (right_item->result_type() != STRING_RESULT ||
            value->result_type() != STRING_RESULT ||
            right_item->collation.collation == value->collation.collation))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4642 4643
  {
    Item *tmp=value->new_item();
4644 4645
    tmp->collation.set(left_item->collation);
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4646 4647
    if (tmp)
    {
4648 4649
      thd->change_item_tree(args, tmp);
      value= tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4650 4651 4652 4653
      func->update_used_tables();
      if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
	  && and_father != cond && !right_item->const_item())
      {
4654
        args[0]= args[1];                       // For easy check
4655
        thd->change_item_tree(args + 1, value);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4656 4657 4658 4659 4660
	cond->marker=1;
	COND_CMP *tmp2;
	if ((tmp2=new COND_CMP(and_father,func)))
	  save_list->push_back(tmp2);
      }
4661
      func->set_cmp_func();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4662 4663 4664 4665
    }
  }
}

4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698
/*
  Remove additional condition inserted by IN/ALL/ANY transformation

  SYNOPSIS
    remove_additional_cond()
    conds - condition for processing

  RETURN VALUES
    new conditions
*/

static Item *remove_additional_cond(Item* conds)
{
  if (conds->name == in_additional_cond)
    return 0;
  if (conds->type() == Item::COND_ITEM)
  {
    Item_cond *cnd= (Item_cond*) conds;
    List_iterator<Item> li(*(cnd->argument_list()));
    Item *item;
    while ((item= li++))
    {
      if (item->name == in_additional_cond)
      {
	li.remove();
	if (cnd->argument_list()->elements == 1)
	  return cnd->argument_list()->head();
	return conds;
      }
    }
  }
  return conds;
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4699 4700

static void
4701 4702
propagate_cond_constants(THD *thd, I_List<COND_CMP> *save_list,
                         COND *and_father, COND *cond)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4703 4704 4705 4706 4707
{
  if (cond->type() == Item::COND_ITEM)
  {
    bool and_level= ((Item_cond*) cond)->functype() ==
      Item_func::COND_AND_FUNC;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4708
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4709 4710 4711 4712
    Item *item;
    I_List<COND_CMP> save;
    while ((item=li++))
    {
4713
      propagate_cond_constants(thd, &save,and_level ? cond : item, item);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4714 4715 4716 4717 4718 4719
    }
    if (and_level)
    {						// Handle other found items
      I_List_iterator<COND_CMP> cond_itr(save);
      COND_CMP *cond_cmp;
      while ((cond_cmp=cond_itr++))
4720 4721 4722 4723 4724 4725
      {
        Item **args= cond_cmp->cmp_func->arguments();
        if (!args[0]->const_item())
          change_cond_ref_to_const(thd, &save,cond_cmp->and_level,
                                   cond_cmp->and_level, args[0], args[1]);
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4726 4727
    }
  }
4728
  else if (and_father != cond && !cond->marker)		// In a AND group
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4729 4730 4731 4732 4733 4734
  {
    if (cond->type() == Item::FUNC_ITEM &&
	(((Item_func*) cond)->functype() == Item_func::EQ_FUNC ||
	 ((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC))
    {
      Item_func_eq *func=(Item_func_eq*) cond;
4735 4736 4737
      Item **args= func->arguments();
      bool left_const= args[0]->const_item();
      bool right_const= args[1]->const_item();
4738
      if (!(left_const && right_const) &&
4739
          args[0]->result_type() == args[1]->result_type())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4740 4741 4742
      {
	if (right_const)
	{
4743
          resolve_const_item(thd, &args[1], args[0]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4744
	  func->update_used_tables();
4745 4746
          change_cond_ref_to_const(thd, save_list, and_father, and_father,
                                   args[0], args[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4747 4748 4749
	}
	else if (left_const)
	{
4750
          resolve_const_item(thd, &args[0], args[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4751
	  func->update_used_tables();
4752 4753
          change_cond_ref_to_const(thd, save_list, and_father, and_father,
                                   args[1], args[0]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4754 4755 4756 4757 4758 4759 4760 4761
	}
      }
    }
  }
}


static COND *
4762
optimize_cond(THD *thd, COND *conds, Item::cond_result *cond_value)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4763
{
4764
  SELECT_LEX *select= thd->lex->current_select;
4765
  DBUG_ENTER("optimize_cond");
4766 4767 4768 4769
  if (conds)
  {
    DBUG_EXECUTE("where", print_where(conds, "original"););
    /* change field = field to field = const for each found field = const */
4770
    propagate_cond_constants(thd, (I_List<COND_CMP> *) 0, conds, conds);
4771 4772 4773 4774 4775 4776 4777 4778 4779
    /*
      Remove all instances of item == item
      Remove all and-levels where CONST item != CONST item
    */
    DBUG_EXECUTE("where", print_where(conds, "after const change"););
    conds= remove_eq_conds(thd, conds, cond_value);
    DBUG_EXECUTE("info", print_where(conds, "after remove"););
  }
  else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4780
    *cond_value= Item::COND_TRUE;
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
4781

4782
  DBUG_RETURN(conds);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4783 4784 4785 4786
}


/*
4787 4788 4789 4790 4791
  Remove const and eq items. Return new item, or NULL if no condition
  cond_value is set to according:
  COND_OK    query is possible (field = constant)
  COND_TRUE  always true	( 1 = 1 )
  COND_FALSE always false	( 1 = 2 )
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4792 4793
*/

4794
COND *
4795
remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4796 4797 4798 4799 4800 4801 4802
{
  if (cond->type() == Item::COND_ITEM)
  {
    bool and_level= ((Item_cond*) cond)->functype()
      == Item_func::COND_AND_FUNC;
    List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
    Item::cond_result tmp_cond_value;
4803
    bool should_fix_fields=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4804 4805 4806 4807 4808

    *cond_value=Item::COND_UNDEF;
    Item *item;
    while ((item=li++))
    {
4809
      Item *new_item=remove_eq_conds(thd, item, &tmp_cond_value);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4810 4811 4812 4813 4814
      if (!new_item)
	li.remove();
      else if (item != new_item)
      {
	VOID(li.replace(new_item));
4815
	should_fix_fields=1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841
      }
      if (*cond_value == Item::COND_UNDEF)
	*cond_value=tmp_cond_value;
      switch (tmp_cond_value) {
      case Item::COND_OK:			// Not TRUE or FALSE
	if (and_level || *cond_value == Item::COND_FALSE)
	  *cond_value=tmp_cond_value;
	break;
      case Item::COND_FALSE:
	if (and_level)
	{
	  *cond_value=tmp_cond_value;
	  return (COND*) 0;			// Always false
	}
	break;
      case Item::COND_TRUE:
	if (!and_level)
	{
	  *cond_value= tmp_cond_value;
	  return (COND*) 0;			// Always true
	}
	break;
      case Item::COND_UNDEF:			// Impossible
	break; /* purecov: deadcode */
      }
    }
4842
    if (should_fix_fields)
4843
      cond->update_used_tables();
4844

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858
    if (!((Item_cond*) cond)->argument_list()->elements ||
	*cond_value != Item::COND_OK)
      return (COND*) 0;
    if (((Item_cond*) cond)->argument_list()->elements == 1)
    {						// Remove list
      item= ((Item_cond*) cond)->argument_list()->head();
      ((Item_cond*) cond)->argument_list()->empty();
      return item;
    }
  }
  else if (cond->type() == Item::FUNC_ITEM &&
	   ((Item_func*) cond)->functype() == Item_func::ISNULL_FUNC)
  {
    /*
4859 4860 4861 4862 4863 4864 4865
      Handles this special case for some ODBC applications:
      The are requesting the row that was just updated with a auto_increment
      value with this construct:

      SELECT * from table_name where auto_increment_column IS NULL
      This will be changed to:
      SELECT * from table_name where auto_increment_column = LAST_INSERT_ID
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4866 4867 4868 4869 4870 4871 4872 4873
    */

    Item_func_isnull *func=(Item_func_isnull*) cond;
    Item **args= func->arguments();
    if (args[0]->type() == Item::FIELD_ITEM)
    {
      Field *field=((Item_field*) args[0])->field;
      if (field->flags & AUTO_INCREMENT_FLAG && !field->table->maybe_null &&
4874
	  (thd->options & OPTION_AUTO_IS_NULL) &&
4875
	  thd->current_insert_id && thd->substitute_null_with_insert_id)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4876
      {
4877
#ifdef HAVE_QUERY_CACHE
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
4878
	query_cache_abort(&thd->net);
4879
#endif
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4880 4881 4882
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],
					new Item_int("last_insert_id()",
4883
						     thd->current_insert_id,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4884 4885
						     21))))
	{
4886 4887 4888 4889 4890 4891 4892
          /*
            Set THD::last_insert_id_used manually, as this statement
            uses LAST_INSERT_ID() in a sense, and should issue
            LAST_INSERT_ID_EVENT.
          */
          thd->last_insert_id_used= TRUE;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4893
	  cond=new_cond;
4894
	  cond->fix_fields(thd, 0, &cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4895
	}
4896
	thd->substitute_null_with_insert_id= FALSE;   // Clear for next request
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4897 4898 4899 4900
      }
      /* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
      else if (((field->type() == FIELD_TYPE_DATE) ||
		(field->type() == FIELD_TYPE_DATETIME)) &&
4901 4902
		(field->flags & NOT_NULL_FLAG) &&
	       !field->table->maybe_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4903 4904 4905 4906 4907
      {
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
	{
	  cond=new_cond;
4908
	  cond->fix_fields(thd, 0, &cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921
	}
      }
    }
  }
  else if (cond->const_item())
  {
    *cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
    return (COND*) 0;
  }
  else if ((*cond_value= cond->eq_cmp_result()) != Item::COND_OK)
  {						// boolan compare function
    Item *left_item=	((Item_func*) cond)->arguments()[0];
    Item *right_item= ((Item_func*) cond)->arguments()[1];
4922
    if (left_item->eq(right_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4923 4924 4925 4926 4927 4928 4929
    {
      if (!left_item->maybe_null ||
	  ((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC)
	return (COND*) 0;			// Compare of identical items
    }
  }
  *cond_value=Item::COND_OK;
4930
  return cond;					// Point at next and level
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4931 4932 4933
}

/*
4934
  Return 1 if the item is a const value in all the WHERE clause
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4935 4936 4937 4938 4939 4940 4941 4942 4943
*/

static bool
const_expression_in_where(COND *cond, Item *comp_item, Item **const_item)
{
  if (cond->type() == Item::COND_ITEM)
  {
    bool and_level= (((Item_cond*) cond)->functype()
		     == Item_func::COND_AND_FUNC);
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4944
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966
    Item *item;
    while ((item=li++))
    {
      bool res=const_expression_in_where(item, comp_item, const_item);
      if (res)					// Is a const value
      {
	if (and_level)
	  return 1;
      }
      else if (!and_level)
	return 0;
    }
    return and_level ? 0 : 1;
  }
  else if (cond->eq_cmp_result() != Item::COND_OK)
  {						// boolan compare function
    Item_func* func= (Item_func*) cond;
    if (func->functype() != Item_func::EQUAL_FUNC &&
	func->functype() != Item_func::EQ_FUNC)
      return 0;
    Item *left_item=	((Item_func*) cond)->arguments()[0];
    Item *right_item= ((Item_func*) cond)->arguments()[1];
4967
    if (left_item->eq(comp_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4968 4969 4970 4971
    {
      if (right_item->const_item())
      {
	if (*const_item)
4972
	  return right_item->eq(*const_item, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4973 4974 4975 4976
	*const_item=right_item;
	return 1;
      }
    }
4977
    else if (right_item->eq(comp_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4978 4979 4980 4981
    {
      if (left_item->const_item())
      {
	if (*const_item)
4982
	  return left_item->eq(*const_item, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4983 4984 4985 4986 4987 4988 4989 4990 4991 4992
	*const_item=left_item;
	return 1;
      }
    }
  }
  return 0;
}


/****************************************************************************
4993
  Create internal temporary table
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4994 4995
****************************************************************************/

4996 4997 4998 4999 5000 5001 5002
/*
  Create field for temporary table from given field
  
  SYNOPSIS
    create_tmp_field_from_field()
    thd			Thread handler
    org_field           field from which new field will be created
5003
    name                New field name
5004 5005
    item		Item to create a field for
    table		Temporary table
5006 5007 5008
    item	        !=NULL if item->result_field should point to new field.
			This is relevant for how fill_record() is going to work:
			If item != NULL then fill_record() will update
5009
			the record in the original table.
5010
			If item == NULL then fill_record() will update
5011
			the temporary table
5012 5013
    convert_blob_length If >0 create a varstring(convert_blob_length) field 
                        instead of blob.
5014 5015 5016 5017 5018

  RETURN
    0			on error
    new_created field
*/
5019 5020

static Field* create_tmp_field_from_field(THD *thd, Field* org_field,
5021 5022
                                          const char *name, TABLE *table,
                                          Item_field *item,
5023
                                          uint convert_blob_length)
5024 5025 5026
{
  Field *new_field;

5027 5028 5029 5030 5031
  if (convert_blob_length && org_field->flags & BLOB_FLAG)
    new_field= new Field_varstring(convert_blob_length, org_field->maybe_null(),
                                   org_field->field_name, table,
                                   org_field->charset());
  else
5032
    new_field= org_field->new_field(thd->mem_root, table);
5033
  if (new_field)
5034
  {
5035 5036
    if (item)
      item->result_field= new_field;
5037
    else
5038
      new_field->field_name= name;
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
5039
    if (org_field->maybe_null() || (item && item->maybe_null))
5040 5041 5042
      new_field->flags&= ~NOT_NULL_FLAG;	// Because of outer join
    if (org_field->type() == FIELD_TYPE_VAR_STRING)
      table->db_create_options|= HA_OPTION_PACK_RECORD;
5043 5044
    else if (org_field->type() == FIELD_TYPE_DOUBLE)
      ((Field_double *) new_field)->not_fixed= TRUE;
5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065
  }
  return new_field;
}

/*
  Create field for temporary table using type of given item
  
  SYNOPSIS
    create_tmp_field_from_item()
    thd			Thread handler
    item		Item to create a field for
    table		Temporary table
    copy_func		If set and item is a function, store copy of item
			in this array
    modify_item		1 if item->result_field should point to new item.
			This is relevent for how fill_record() is going to
			work:
			If modify_item is 1 then fill_record() will update
			the record in the original table.
			If modify_item is 0 then fill_record() will update
			the temporary table
5066 5067
    convert_blob_length If >0 create a varstring(convert_blob_length) field 
                        instead of blob.
5068 5069 5070 5071 5072

  RETURN
    0			on error
    new_created field
*/
5073 5074 5075
static Field* create_tmp_field_from_item(THD *thd, Item *item, TABLE *table,
                                         Item ***copy_func, bool modify_item,
                                         uint convert_blob_length)
5076 5077 5078 5079 5080 5081 5082 5083
{
  bool maybe_null=item->maybe_null;
  Field *new_field;
  LINT_INIT(new_field);

  switch (item->result_type()) {
  case REAL_RESULT:
    new_field=new Field_double(item->max_length, maybe_null,
5084
			       item->name, table, item->decimals, TRUE);
5085 5086 5087 5088 5089 5090
    break;
  case INT_RESULT:
    new_field=new Field_longlong(item->max_length, maybe_null,
				   item->name, table, item->unsigned_flag);
    break;
  case STRING_RESULT:
5091
    DBUG_ASSERT(item->collation.collation);
5092
  
5093 5094 5095 5096 5097 5098 5099 5100
    enum enum_field_types type;
    /*
      DATE/TIME fields have STRING_RESULT result type. To preserve
      type they needed to be handled separately.
    */
    if ((type= item->field_type()) == MYSQL_TYPE_DATETIME ||
        type == MYSQL_TYPE_TIME || type == MYSQL_TYPE_DATE)
      new_field= item->tmp_table_field_from_field_type(table);
5101 5102
    else if (item->max_length/item->collation.collation->mbmaxlen >
             CONVERT_IF_BIGGER_TO_BLOB)
5103 5104 5105 5106 5107 5108 5109 5110 5111
    {
      if (convert_blob_length)
        new_field= new Field_varstring(convert_blob_length, maybe_null,
                                       item->name, table,
                                       item->collation.collation);
      else
        new_field= new Field_blob(item->max_length, maybe_null, item->name,
                                  table, item->collation.collation);
    }
5112
    else
5113 5114
      new_field= new Field_string(item->max_length, maybe_null, item->name, 
                                  table, item->collation.collation);
5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129
    break;
  case ROW_RESULT: 
  default: 
    // This case should never be choosen
    DBUG_ASSERT(0);
    new_field= 0; // to satisfy compiler (uninitialized variable)
    break;
  }
  if (copy_func && item->is_result_field())
    *((*copy_func)++) = item;			// Save for copy_funcs
  if (modify_item)
    item->set_result_field(new_field);
  return new_field;
}

5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140
/*
  Create field for temporary table

  SYNOPSIS
    create_tmp_field()
    thd			Thread handler
    table		Temporary table
    item		Item to create a field for
    type		Type of item (normally item->type)
    copy_func		If set and item is a function, store copy of item
			in this array
5141
    from_field          if field will be created using other field as example,
serg@serg.mylan's avatar
serg@serg.mylan committed
5142
                        pointer example field will be written here
5143 5144 5145 5146 5147 5148 5149 5150
    group		1 if we are going to do a relative group by on result
    modify_item		1 if item->result_field should point to new item.
			This is relevent for how fill_record() is going to
			work:
			If modify_item is 1 then fill_record() will update
			the record in the original table.
			If modify_item is 0 then fill_record() will update
			the temporary table
5151 5152
    convert_blob_length If >0 create a varstring(convert_blob_length) field 
                        instead of blob.
serg@serg.mylan's avatar
serg@serg.mylan committed
5153

5154 5155 5156 5157 5158
  RETURN
    0			on error
    new_created field
*/

5159
Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
5160
                        Item ***copy_func, Field **from_field,
5161 5162
                        bool group, bool modify_item, uint convert_blob_length,
                        bool make_copy_field)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5163 5164 5165 5166 5167 5168 5169 5170 5171 5172
{
  switch (type) {
  case Item::SUM_FUNC_ITEM:
  {
    Item_sum *item_sum=(Item_sum*) item;
    bool maybe_null=item_sum->maybe_null;
    switch (item_sum->sum_func()) {
    case Item_sum::AVG_FUNC:			/* Place for sum & count */
      if (group)
	return new Field_string(sizeof(double)+sizeof(longlong),
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
5173
				0, item->name,table,&my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5174
      else
5175 5176
	return new Field_double(item_sum->max_length, maybe_null,
				item->name, table, item_sum->decimals, TRUE);
5177
    case Item_sum::VARIANCE_FUNC:		/* Place for sum & count */
serg@serg.mylan's avatar
serg@serg.mylan committed
5178
    case Item_sum::STD_FUNC:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5179 5180
      if (group)
	return	new Field_string(sizeof(double)*2+sizeof(longlong),
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
5181
				 0, item->name,table,&my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5182 5183
      else
	return new Field_double(item_sum->max_length, maybe_null,
5184
				item->name, table, item_sum->decimals, TRUE);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5185 5186
    case Item_sum::UNIQUE_USERS_FUNC:
      return new Field_long(9,maybe_null,item->name,table,1);
5187 5188 5189 5190 5191
    case Item_sum::MIN_FUNC:
    case Item_sum::MAX_FUNC:
      if (item_sum->args[0]->type() == Item::FIELD_ITEM)
      {
        *from_field= ((Item_field*) item_sum->args[0])->field;
5192 5193
        return create_tmp_field_from_field(thd, *from_field, item->name, table,
                                           NULL, convert_blob_length);
5194 5195
      }
      /* fall through */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5196 5197 5198
    default:
      switch (item_sum->result_type()) {
      case REAL_RESULT:
5199 5200
	return new Field_double(item_sum->max_length, maybe_null,
				item->name, table, item_sum->decimals, TRUE);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5201 5202
      case INT_RESULT:
	return new Field_longlong(item_sum->max_length,maybe_null,
5203
				  item->name,table,item->unsigned_flag);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5204
      case STRING_RESULT:
5205 5206
	if (item_sum->max_length/item_sum->collation.collation->mbmaxlen >
            CONVERT_IF_BIGGER_TO_BLOB)
5207 5208 5209 5210 5211 5212 5213 5214 5215
        {
          if (convert_blob_length)
            return new Field_varstring(convert_blob_length, maybe_null,
                                       item->name, table,
                                       item->collation.collation);
          else
            return new Field_blob(item_sum->max_length, maybe_null, item->name,
                                  table, item->collation.collation);
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5216
	return	new Field_string(item_sum->max_length,maybe_null,
5217
				 item->name,table,item->collation.collation);
5218
      case ROW_RESULT:
5219
      default:
5220 5221
	// This case should never be choosen
	DBUG_ASSERT(0);
5222
	thd->fatal_error();
5223
	return 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5224 5225
      }
    }
5226
    /* We never come here */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5227 5228
  }
  case Item::FIELD_ITEM:
5229
  case Item::DEFAULT_VALUE_ITEM:
5230 5231
  {
    Item_field *field= (Item_field*) item;
5232 5233 5234 5235
    return create_tmp_field_from_field(thd, (*from_field= field->field),
                                       item->name, table,
                                       modify_item ? (Item_field*) item : NULL,
                                       convert_blob_length);
5236
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5237 5238 5239 5240
  case Item::FUNC_ITEM:
  case Item::COND_ITEM:
  case Item::FIELD_AVG_ITEM:
  case Item::FIELD_STD_ITEM:
5241
  case Item::SUBSELECT_ITEM:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5242
    /* The following can only happen with 'CREATE TABLE ... SELECT' */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5243
  case Item::PROC_ITEM:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5244 5245 5246 5247
  case Item::INT_ITEM:
  case Item::REAL_ITEM:
  case Item::STRING_ITEM:
  case Item::REF_ITEM:
5248
  case Item::NULL_ITEM:
5249
  case Item::VARBIN_ITEM:
5250 5251 5252 5253 5254 5255 5256
    if (make_copy_field)
    {
      DBUG_ASSERT(((Item_result_field*)item)->result_field);
      *from_field= ((Item_result_field*)item)->result_field;
    }
    return create_tmp_field_from_item(thd, item, table, (make_copy_field ? 0 :
                                      copy_func), modify_item,
5257
                                      convert_blob_length);
5258
  case Item::TYPE_HOLDER:
5259
    return ((Item_type_holder *)item)->make_field_by_type(table);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5260 5261 5262 5263 5264 5265
  default:					// Dosen't have to be stored
    return 0;
  }
}


5266 5267 5268 5269 5270 5271 5272
/*
  Create a temp table according to a field list.
  Set distinct if duplicates could be removed
  Given fields field pointers are changed to point at tmp_table
  for send_fields
*/

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5273 5274 5275
TABLE *
create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
		 ORDER *group, bool distinct, bool save_sum_fields,
5276 5277
		 ulong select_options, ha_rows rows_limit,
		 char *table_alias)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5278 5279 5280
{
  TABLE *table;
  uint	i,field_count,reclength,null_count,null_pack_length,
5281
        hidden_null_count, hidden_null_pack_length, hidden_field_count,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5282 5283
	blob_count,group_null_items;
  bool	using_unique_constraint=0;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
5284
  bool  not_all_columns= !(select_options & TMP_TABLE_ALL_COLUMNS);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5285 5286 5287
  char	*tmpname,path[FN_REFLEN];
  byte	*pos,*group_buff;
  uchar *null_flags;
5288
  Field **reg_field, **from_field, **blob_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5289 5290 5291
  Copy_field *copy=0;
  KEY *keyinfo;
  KEY_PART_INFO *key_part_info;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5292
  Item **copy_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5293
  MI_COLUMNDEF *recinfo;
5294
  uint temp_pool_slot=MY_BIT_NONE;
5295
  bool force_copy_fields= param->force_copy_fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5296
  DBUG_ENTER("create_tmp_table");
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5297
  DBUG_PRINT("enter",("distinct: %d  save_sum_fields: %d  rows_limit: %lu  group: %d",
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5298
		      (int) distinct, (int) save_sum_fields,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5299
		      (ulong) rows_limit,test(group)));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5300

5301
  statistic_increment(created_tmp_tables, &LOCK_status);
5302

5303
  if (use_temp_pool)
5304
    temp_pool_slot = bitmap_set_next(&temp_pool);
5305 5306

  if (temp_pool_slot != MY_BIT_NONE) // we got a slot
5307
    sprintf(path, "%s_%lx_%i", tmp_file_prefix,
5308 5309
	    current_pid, temp_pool_slot);
  else // if we run out of slots or we are not using tempool
5310
    sprintf(path,"%s%lx_%lx_%x", tmp_file_prefix,current_pid,
5311
            thd->thread_id, thd->tmp_table++);
serg@serg.mylan's avatar
serg@serg.mylan committed
5312

5313 5314
  fn_format(path, path, mysql_tmpdir, "", MY_REPLACE_EXT|MY_UNPACK_FILENAME);

5315 5316
  if (lower_case_table_names)
    my_casedn_str(files_charset_info, path);
5317

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5318 5319 5320 5321 5322
  if (group)
  {
    if (!param->quick_group)
      group=0;					// Can't use group key
    else for (ORDER *tmp=group ; tmp ; tmp=tmp->next)
5323
    {
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5324
      (*tmp->item)->marker=4;			// Store null in key
5325 5326 5327
      if ((*tmp->item)->max_length >= MAX_CHAR_WIDTH)
	using_unique_constraint=1;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5328 5329
    if (param->group_length >= MAX_BLOB_WIDTH)
      using_unique_constraint=1;
5330 5331
    if (group)
      distinct=0;				// Can't use distinct
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5332 5333 5334
  }

  field_count=param->field_count+param->func_count+param->sum_func_count;
5335
  hidden_field_count=param->hidden_field_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5336 5337
  if (!my_multi_malloc(MYF(MY_WME),
		       &table,sizeof(*table),
5338 5339 5340
		       &reg_field,  sizeof(Field*)*(field_count+1),
		       &blob_field, sizeof(Field*)*(field_count+1),
		       &from_field, sizeof(Field*)*field_count,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351
		       &copy_func,sizeof(*copy_func)*(param->func_count+1),
		       &param->keyinfo,sizeof(*param->keyinfo),
		       &key_part_info,
		       sizeof(*key_part_info)*(param->group_parts+1),
		       &param->start_recinfo,
		       sizeof(*param->recinfo)*(field_count*2+4),
		       &tmpname,(uint) strlen(path)+1,
		       &group_buff,group && ! using_unique_constraint ?
		       param->group_length : 0,
		       NullS))
  {
5352 5353
    if (temp_pool_slot != MY_BIT_NONE)
      bitmap_clear_bit(&temp_pool, temp_pool_slot);
5354
    DBUG_RETURN(NULL);				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5355 5356 5357
  }
  if (!(param->copy_field=copy=new Copy_field[field_count]))
  {
5358 5359
    if (temp_pool_slot != MY_BIT_NONE)
      bitmap_clear_bit(&temp_pool, temp_pool_slot);
5360 5361
    my_free((gptr) table,MYF(0));		/* purecov: inspected */
    DBUG_RETURN(NULL);				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5362
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5363
  param->items_to_copy= copy_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5364 5365 5366 5367 5368 5369 5370
  strmov(tmpname,path);
  /* make table according to fields */

  bzero((char*) table,sizeof(*table));
  bzero((char*) reg_field,sizeof(Field*)*(field_count+1));
  bzero((char*) from_field,sizeof(Field*)*field_count);
  table->field=reg_field;
5371
  table->blob_field= (Field_blob**) blob_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5372
  table->real_name=table->path=tmpname;
5373
  table->table_name= table_alias;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5374 5375 5376 5377
  table->reginfo.lock_type=TL_WRITE;	/* Will be updated */
  table->db_stat=HA_OPEN_KEYFILE+HA_OPEN_RNDFILE;
  table->blob_ptr_size=mi_portable_sizeof_char_ptr;
  table->map=1;
5378
  table->tmp_table= TMP_TABLE;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5379
  table->db_low_byte_first=1;			// True for HEAP and MyISAM
5380
  table->temp_pool_slot = temp_pool_slot;
5381
  table->copy_blobs= 1;
5382
  table->in_use= thd;
5383 5384 5385 5386 5387 5388
  table->keys_for_keyread.init();
  table->keys_in_use.init();
  table->read_only_keys.init();
  table->quick_keys.init();
  table->used_keys.init();
  table->keys_in_use_for_query.init();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5389

5390
  /* Calculate which type of fields we will store in the temporary table */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5391

5392 5393
  reclength=blob_count=null_count=hidden_null_count=group_null_items=0;
  param->using_indirect_summary_function=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5394

monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
5395
  List_iterator_fast<Item> li(fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5396 5397
  Item *item;
  Field **tmp_from_field=from_field;
5398
  while ((item=li++))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5399 5400
  {
    Item::Type type=item->type();
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
5401
    if (not_all_columns)
5402
    {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
5403 5404 5405 5406 5407 5408 5409 5410 5411 5412
      if (item->with_sum_func && type != Item::SUM_FUNC_ITEM)
      {
	/*
	  Mark that the we have ignored an item that refers to a summary
	  function. We need to know this if someone is going to use
	  DISTINCT on the result.
	*/
	param->using_indirect_summary_function=1;
	continue;
      }
5413
      if (item->const_item() && (int) hidden_field_count <= 0)
5414
        continue; // We don't have to store this
5415
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5416 5417 5418 5419 5420
    if (type == Item::SUM_FUNC_ITEM && !group && !save_sum_fields)
    {						/* Can't calc group yet */
      ((Item_sum*) item)->result_field=0;
      for (i=0 ; i < ((Item_sum*) item)->arg_count ; i++)
      {
5421 5422
	Item **argp= ((Item_sum*) item)->args + i;
	Item *arg= *argp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5423 5424 5425
	if (!arg->const_item())
	{
	  Field *new_field=
5426 5427
            create_tmp_field(thd, table, arg, arg->type(), &copy_func,
                             tmp_from_field, group != 0,not_all_columns,
5428
                             param->convert_blob_length, 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5429 5430 5431 5432 5433 5434
	  if (!new_field)
	    goto err;					// Should be OOM
	  tmp_from_field++;
	  *(reg_field++)= new_field;
	  reclength+=new_field->pack_length();
	  if (new_field->flags & BLOB_FLAG)
5435 5436
	  {
	    *blob_field++= new_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5437
	    blob_count++;
5438
	  }
5439
          thd->change_item_tree(argp, new Item_field(new_field));
serg@serg.mylan's avatar
serg@serg.mylan committed
5440 5441 5442 5443 5444 5445 5446
	  if (!(new_field->flags & NOT_NULL_FLAG))
          {
	    null_count++;
            /*
              new_field->maybe_null() is still false, it will be
              changed below. But we have to setup Item_field correctly
            */
5447
            (*argp)->maybe_null=1;
serg@serg.mylan's avatar
serg@serg.mylan committed
5448
          }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5449 5450 5451 5452 5453
	}
      }
    }
    else
    {
5454 5455 5456 5457 5458 5459 5460 5461 5462 5463
      /*
	The last parameter to create_tmp_field() is a bit tricky:

	We need to set it to 0 in union, to get fill_record() to modify the
	temporary table.
	We need to set it to 1 on multi-table-update and in select to
	write rows to the temporary table.
	We here distinguish between UNION and multi-table-updates by the fact
	that in the later case group is set to the row pointer.
      */
5464 5465
      Field *new_field= create_tmp_field(thd, table, item, type, &copy_func,
                                         tmp_from_field, group != 0,
5466 5467 5468 5469
                                         !force_copy_fields &&
                                           (not_all_columns || group !=0),
                                         param->convert_blob_length,
                                         force_copy_fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5470 5471
      if (!new_field)
      {
5472
	if (thd->is_fatal_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5473 5474 5475 5476 5477 5478 5479 5480 5481 5482
	  goto err;				// Got OOM
	continue;				// Some kindf of const item
      }
      if (type == Item::SUM_FUNC_ITEM)
	((Item_sum *) item)->result_field= new_field;
      tmp_from_field++;
      reclength+=new_field->pack_length();
      if (!(new_field->flags & NOT_NULL_FLAG))
	null_count++;
      if (new_field->flags & BLOB_FLAG)
5483 5484
      {
	*blob_field++= new_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5485
	blob_count++;
5486
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5487 5488 5489 5490 5491 5492 5493
      if (item->marker == 4 && item->maybe_null)
      {
	group_null_items++;
	new_field->flags|= GROUP_FLAG;
      }
      *(reg_field++) =new_field;
    }
5494
    if (!--hidden_field_count)
5495
    {
5496
      hidden_null_count=null_count;
5497 5498 5499 5500 5501 5502
      /*
        We need to update hidden_field_count as we may have stored group
        functions with constant arguments
      */
      param->hidden_field_count= (uint) (reg_field - table->field);
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5503
  }
5504
  DBUG_ASSERT(field_count >= (uint) (reg_field - table->field));
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
5505
  field_count= (uint) (reg_field - table->field);
5506
  *blob_field= 0;				// End marker
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5507 5508

  /* If result table is small; use a heap */
5509
  if (blob_count || using_unique_constraint ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5510
      (select_options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
5511
      OPTION_BIG_TABLES ||(select_options & TMP_TABLE_FORCE_MYISAM))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528
  {
    table->file=get_new_handler(table,table->db_type=DB_TYPE_MYISAM);
    if (group &&
	(param->group_parts > table->file->max_key_parts() ||
	 param->group_length > table->file->max_key_length()))
      using_unique_constraint=1;
  }
  else
  {
    table->file=get_new_handler(table,table->db_type=DB_TYPE_HEAP);
  }

  if (!using_unique_constraint)
    reclength+= group_null_items;	// null flag is stored separately

  table->blob_fields=blob_count;
  if (blob_count == 0)
5529 5530
  {
    /* We need to ensure that first byte is not 0 for the delete link */
5531
    if (param->hidden_field_count)
5532 5533 5534 5535 5536 5537 5538
      hidden_null_count++;
    else
      null_count++;
  }
  hidden_null_pack_length=(hidden_null_count+7)/8;
  null_pack_length=hidden_null_count+(null_count+7)/8;
  reclength+=null_pack_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5539 5540 5541 5542 5543 5544 5545 5546
  if (!reclength)
    reclength=1;				// Dummy select

  table->fields=field_count;
  table->reclength=reclength;
  {
    uint alloc_length=ALIGN_SIZE(reclength+MI_UNIQUE_HASH_LENGTH+1);
    table->rec_buff_length=alloc_length;
5547
    if (!(table->record[0]= (byte *) my_malloc(alloc_length*3, MYF(MY_WME))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5548
      goto err;
5549
    table->record[1]= table->record[0]+alloc_length;
5550
    table->default_values= table->record[1]+alloc_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561 5562 5563
  }
  copy_func[0]=0;				// End marker

  recinfo=param->start_recinfo;
  null_flags=(uchar*) table->record[0];
  pos=table->record[0]+ null_pack_length;
  if (null_pack_length)
  {
    bzero((byte*) recinfo,sizeof(*recinfo));
    recinfo->type=FIELD_NORMAL;
    recinfo->length=null_pack_length;
    recinfo++;
    bfill(null_flags,null_pack_length,255);	// Set null fields
5564 5565 5566 5567

    table->null_flags= (uchar*) table->record[0];
    table->null_fields= null_count+ hidden_null_count;
    table->null_bytes= null_pack_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5568 5569
  }
  null_count= (blob_count == 0) ? 1 : 0;
5570
  hidden_field_count=param->hidden_field_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5571 5572 5573 5574 5575 5576 5577 5578 5579 5580
  for (i=0,reg_field=table->field; i < field_count; i++,reg_field++,recinfo++)
  {
    Field *field= *reg_field;
    uint length;
    bzero((byte*) recinfo,sizeof(*recinfo));

    if (!(field->flags & NOT_NULL_FLAG))
    {
      if (field->flags & GROUP_FLAG && !using_unique_constraint)
      {
5581 5582 5583 5584
	/*
	  We have to reserve one byte here for NULL bits,
	  as this is updated by 'end_update()'
	*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618
	*pos++=0;				// Null is stored here
	recinfo->length=1;
	recinfo->type=FIELD_NORMAL;
	recinfo++;
	bzero((byte*) recinfo,sizeof(*recinfo));
      }
      else
      {
	recinfo->null_bit= 1 << (null_count & 7);
	recinfo->null_pos= null_count/8;
      }
      field->move_field((char*) pos,null_flags+null_count/8,
			1 << (null_count & 7));
      null_count++;
    }
    else
      field->move_field((char*) pos,(uchar*) 0,0);
    field->reset();
    if (from_field[i])
    {						/* Not a table Item */
      copy->set(field,from_field[i],save_sum_fields);
      copy++;
    }
    length=field->pack_length();
    pos+= length;

    /* Make entry for create table */
    recinfo->length=length;
    if (field->flags & BLOB_FLAG)
      recinfo->type= (int) FIELD_BLOB;
    else if (!field->zero_pack() &&
	     (field->type() == FIELD_TYPE_STRING ||
	      field->type() == FIELD_TYPE_VAR_STRING) &&
	     length >= 10 && blob_count)
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
5619
      recinfo->type=FIELD_SKIP_ENDSPACE;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5620 5621
    else
      recinfo->type=FIELD_NORMAL;
5622 5623
    if (!--hidden_field_count)
      null_count=(null_count+7) & ~7;		// move to next byte
5624 5625 5626

    // fix table name in field entry
    field->table_name= table->table_name;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5627 5628
  }

monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
5629
  param->copy_field_end=copy;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5630
  param->recinfo=recinfo;
5631
  store_record(table,default_values);		// Make empty default record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5632

5633
  if (thd->variables.tmp_table_size == ~(ulong) 0)		// No limit
5634 5635 5636
    table->max_rows= ~(ha_rows) 0;
  else
    table->max_rows=(((table->db_type == DB_TYPE_HEAP) ?
5637 5638 5639
		      min(thd->variables.tmp_table_size,
			  thd->variables.max_heap_table_size) :
		      thd->variables.tmp_table_size)/ table->reclength);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5640
  set_if_bigger(table->max_rows,1);		// For dummy start options
5641 5642 5643 5644 5645 5646 5647
  /*
    Push the LIMIT clause to the temporary table creation, so that we
    materialize only up to 'rows_limit' records instead of all result records.
  */
  set_if_smaller(table->max_rows, rows_limit);
  param->end_write_records= rows_limit;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662
  keyinfo=param->keyinfo;

  if (group)
  {
    DBUG_PRINT("info",("Creating group key in temporary table"));
    table->group=group;				/* Table is grouped by key */
    param->group_buff=group_buff;
    table->keys=1;
    table->uniques= test(using_unique_constraint);
    table->key_info=keyinfo;
    keyinfo->key_part=key_part_info;
    keyinfo->flags=HA_NOSAME;
    keyinfo->usable_key_parts=keyinfo->key_parts= param->group_parts;
    keyinfo->key_length=0;
    keyinfo->rec_per_key=0;
5663
    keyinfo->algorithm= HA_KEY_ALG_UNDEF;
5664 5665
    ORDER *cur_group= group;
    for (; cur_group ; cur_group= cur_group->next, key_part_info++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5666
    {
5667 5668
      Field *field=(*cur_group->item)->get_tmp_table_field();
      bool maybe_null=(*cur_group->item)->maybe_null;
5669
      key_part_info->null_bit=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5670 5671 5672 5673 5674 5675 5676 5677 5678 5679
      key_part_info->field=  field;
      key_part_info->offset= field->offset();
      key_part_info->length= (uint16) field->pack_length();
      key_part_info->type=   (uint8) field->key_type();
      key_part_info->key_type =
	((ha_base_keytype) key_part_info->type == HA_KEYTYPE_TEXT ||
	 (ha_base_keytype) key_part_info->type == HA_KEYTYPE_VARTEXT) ?
	0 : FIELDFLAG_BINARY;
      if (!using_unique_constraint)
      {
5680 5681
	cur_group->buff=(char*) group_buff;
	if (!(cur_group->field=field->new_field(thd->mem_root,table)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5682 5683 5684 5685
	  goto err; /* purecov: inspected */
	if (maybe_null)
	{
	  /*
5686 5687 5688 5689
	    To be able to group on NULL, we reserve place in group_buff
	    for the NULL flag just before the column.
	    The field data is after this flag.
	    The NULL flag is updated by 'end_update()' and 'end_write()'
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5690
	  */
5691 5692 5693 5694
	  keyinfo->flags|= HA_NULL_ARE_EQUAL;	// def. that NULL == NULL
	  key_part_info->null_bit=field->null_bit;
	  key_part_info->null_offset= (uint) (field->null_ptr -
					      (uchar*) table->record[0]);
5695
	  cur_group->field->move_field((char*) ++cur_group->buff);
5696
	  group_buff++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5697 5698
	}
	else
5699
	  cur_group->field->move_field((char*) group_buff);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5700 5701 5702 5703 5704 5705
	group_buff+= key_part_info->length;
      }
      keyinfo->key_length+=  key_part_info->length;
    }
  }

5706
  if (distinct && field_count != param->hidden_field_count)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5707
  {
5708 5709 5710 5711 5712 5713
    /*
      Create an unique key or an unique constraint over all columns
      that should be in the result.  In the temporary table, there are
      'param->hidden_field_count' extra columns, whose null bits are stored
      in the first 'hidden_null_pack_length' bytes of the row.
    */
5714 5715
    DBUG_PRINT("info",("hidden_field_count: %d", param->hidden_field_count));

5716
    null_pack_length-=hidden_null_pack_length;
5717
    keyinfo->key_parts= ((field_count-param->hidden_field_count)+
5718
			 test(null_pack_length));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729 5730
    table->distinct=1;
    table->keys=1;
    if (blob_count)
    {
      using_unique_constraint=1;
      table->uniques=1;
    }
    if (!(key_part_info= (KEY_PART_INFO*)
	  sql_calloc((keyinfo->key_parts)*sizeof(KEY_PART_INFO))))
      goto err;
    table->key_info=keyinfo;
    keyinfo->key_part=key_part_info;
5731
    keyinfo->flags=HA_NOSAME | HA_NULL_ARE_EQUAL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5732 5733
    keyinfo->key_length=(uint16) reclength;
    keyinfo->name=(char*) "tmp";
5734
    keyinfo->algorithm= HA_KEY_ALG_UNDEF;
5735
    keyinfo->rec_per_key=0;
5736
    if (null_pack_length)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5737
    {
5738
      key_part_info->null_bit=0;
5739 5740
      key_part_info->offset=hidden_null_pack_length;
      key_part_info->length=null_pack_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5741 5742 5743 5744 5745
      key_part_info->field=new Field_string((char*) table->record[0],
					    (uint32) key_part_info->length,
					    (uchar*) 0,
					    (uint) 0,
					    Field::NONE,
5746
					    NullS, table, &my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5747 5748 5749 5750
      key_part_info->key_type=FIELDFLAG_BINARY;
      key_part_info->type=    HA_KEYTYPE_BINARY;
      key_part_info++;
    }
5751
    /* Create a distinct key over the columns we are going to return */
5752 5753
    for (i=param->hidden_field_count, reg_field=table->field + i ;
	 i < field_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5754 5755
	 i++, reg_field++, key_part_info++)
    {
5756
      key_part_info->null_bit=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5757 5758 5759 5760 5761 5762 5763 5764 5765 5766
      key_part_info->field=    *reg_field;
      key_part_info->offset=   (*reg_field)->offset();
      key_part_info->length=   (uint16) (*reg_field)->pack_length();
      key_part_info->type=     (uint8) (*reg_field)->key_type();
      key_part_info->key_type =
	((ha_base_keytype) key_part_info->type == HA_KEYTYPE_TEXT ||
	 (ha_base_keytype) key_part_info->type == HA_KEYTYPE_VARTEXT) ?
	0 : FIELDFLAG_BINARY;
    }
  }
5767

5768
  if (thd->is_fatal_error)				// If end of memory
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779
    goto err;					 /* purecov: inspected */
  table->db_record_offset=1;
  if (table->db_type == DB_TYPE_MYISAM)
  {
    if (create_myisam_tmp_table(table,param,select_options))
      goto err;
  }
  if (!open_tmp_table(table))
    DBUG_RETURN(table);

 err:
5780 5781 5782 5783 5784
  /*
    Hack to ensure that free_blobs() doesn't fail if blob_field is not yet
    complete
  */
  *table->blob_field= 0;
5785
  free_tmp_table(thd,table);                    /* purecov: inspected */
5786 5787
  if (temp_pool_slot != MY_BIT_NONE)
    bitmap_clear_bit(&temp_pool, temp_pool_slot);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5788 5789 5790 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806
  DBUG_RETURN(NULL);				/* purecov: inspected */
}


static bool open_tmp_table(TABLE *table)
{
  int error;
  if ((error=table->file->ha_open(table->real_name,O_RDWR,HA_OPEN_TMP_TABLE)))
  {
    table->file->print_error(error,MYF(0)); /* purecov: inspected */
    table->db_stat=0;
    return(1);
  }
  (void) table->file->extra(HA_EXTRA_QUICK);		/* Faster */
  return(0);
}


static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
5807
				    ulong options)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5808 5809 5810 5811 5812 5813 5814 5815 5816 5817
{
  int error;
  MI_KEYDEF keydef;
  MI_UNIQUEDEF uniquedef;
  KEY *keyinfo=param->keyinfo;

  DBUG_ENTER("create_myisam_tmp_table");
  if (table->keys)
  {						// Get keys for ni_create
    bool using_unique_constraint=0;
5818
    HA_KEYSEG *seg= (HA_KEYSEG*) sql_calloc(sizeof(*seg) *
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853
					    keyinfo->key_parts);
    if (!seg)
      goto err;

    if (keyinfo->key_length >= table->file->max_key_length() ||
	keyinfo->key_parts > table->file->max_key_parts() ||
	table->uniques)
    {
      /* Can't create a key; Make a unique constraint instead of a key */
      table->keys=0;
      table->uniques=1;
      using_unique_constraint=1;
      bzero((char*) &uniquedef,sizeof(uniquedef));
      uniquedef.keysegs=keyinfo->key_parts;
      uniquedef.seg=seg;
      uniquedef.null_are_equal=1;

      /* Create extra column for hash value */
      bzero((byte*) param->recinfo,sizeof(*param->recinfo));
      param->recinfo->type= FIELD_CHECK;
      param->recinfo->length=MI_UNIQUE_HASH_LENGTH;
      param->recinfo++;
      table->reclength+=MI_UNIQUE_HASH_LENGTH;
    }
    else
    {
      /* Create an unique key */
      bzero((char*) &keydef,sizeof(keydef));
      keydef.flag=HA_NOSAME | HA_BINARY_PACK_KEY | HA_PACK_KEY;
      keydef.keysegs=  keyinfo->key_parts;
      keydef.seg= seg;
    }
    for (uint i=0; i < keyinfo->key_parts ; i++,seg++)
    {
      Field *field=keyinfo->key_part[i].field;
5854
      seg->flag=     0;
5855
      seg->language= field->charset()->number;
5856 5857
      seg->length=   keyinfo->key_part[i].length;
      seg->start=    keyinfo->key_part[i].offset;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876 5877
      if (field->flags & BLOB_FLAG)
      {
	seg->type=
	((keyinfo->key_part[i].key_type & FIELDFLAG_BINARY) ?
	 HA_KEYTYPE_VARBINARY : HA_KEYTYPE_VARTEXT);
	seg->bit_start=seg->length - table->blob_ptr_size;
	seg->flag= HA_BLOB_PART;
	seg->length=0;			// Whole blob in unique constraint
      }
      else
      {
	seg->type=
	  ((keyinfo->key_part[i].key_type & FIELDFLAG_BINARY) ?
	   HA_KEYTYPE_BINARY : HA_KEYTYPE_TEXT);
	if (!(field->flags & ZEROFILL_FLAG) &&
	    (field->type() == FIELD_TYPE_STRING ||
	     field->type() == FIELD_TYPE_VAR_STRING) &&
	    keyinfo->key_part[i].length > 4)
	  seg->flag|=HA_SPACE_PACK;
      }
5878
      if (!(field->flags & NOT_NULL_FLAG))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5879 5880 5881
      {
	seg->null_bit= field->null_bit;
	seg->null_pos= (uint) (field->null_ptr - (uchar*) table->record[0]);
5882 5883 5884 5885 5886 5887 5888
	/*
	  We are using a GROUP BY on something that contains NULL
	  In this case we have to tell MyISAM that two NULL should
	  on INSERT be compared as equal
	*/
	if (!using_unique_constraint)
	  keydef.flag|= HA_NULL_ARE_EQUAL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5889 5890 5891 5892 5893
      }
    }
  }
  MI_CREATE_INFO create_info;
  bzero((char*) &create_info,sizeof(create_info));
5894

5895 5896
  if ((options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
      OPTION_BIG_TABLES)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909
    create_info.data_file_length= ~(ulonglong) 0;

  if ((error=mi_create(table->real_name,table->keys,&keydef,
		       (uint) (param->recinfo-param->start_recinfo),
		       param->start_recinfo,
		       table->uniques, &uniquedef,
		       &create_info,
		       HA_CREATE_TMP_TABLE)))
  {
    table->file->print_error(error,MYF(0));	/* purecov: inspected */
    table->db_stat=0;
    goto err;
  }
5910
  statistic_increment(created_tmp_disk_tables, &LOCK_status);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5911 5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926
  table->db_record_offset=1;
  DBUG_RETURN(0);
 err:
  DBUG_RETURN(1);
}


void
free_tmp_table(THD *thd, TABLE *entry)
{
  const char *save_proc_info;
  DBUG_ENTER("free_tmp_table");
  DBUG_PRINT("enter",("table: %s",entry->table_name));

  save_proc_info=thd->proc_info;
  thd->proc_info="removing tmp table";
5927
  free_blobs(entry);
5928
  if (entry->file)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5929
  {
5930 5931 5932 5933 5934 5935 5936 5937 5938 5939 5940
    if (entry->db_stat)
    {
      (void) entry->file->close();
    }
    /*
      We can't call ha_delete_table here as the table may created in mixed case
      here and we have to ensure that delete_table gets the table name in
      the original case.
    */
    if (!(test_flags & TEST_KEEP_TMP_TABLES) || entry->db_type == DB_TYPE_HEAP)
      entry->file->delete_table(entry->real_name);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5941 5942
    delete entry->file;
  }
5943

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5944 5945
  /* free blobs */
  for (Field **ptr=entry->field ; *ptr ; ptr++)
5946
    (*ptr)->free();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5947 5948
  my_free((gptr) entry->record[0],MYF(0));
  free_io_cache(entry);
5949

5950 5951
  if (entry->temp_pool_slot != MY_BIT_NONE)
    bitmap_clear_bit(&temp_pool, entry->temp_pool_slot);
5952

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5953 5954 5955 5956 5957 5958 5959 5960 5961 5962
  my_free((gptr) entry,MYF(0));
  thd->proc_info=save_proc_info;

  DBUG_VOID_RETURN;
}

/*
* If a HEAP table gets full, create a MyISAM table and copy all rows to this
*/

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
5963 5964
bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
			     int error, bool ignore_last_dupp_key_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977 5978 5979 5980 5981 5982 5983 5984
{
  TABLE new_table;
  const char *save_proc_info;
  int write_err;
  DBUG_ENTER("create_myisam_from_heap");

  if (table->db_type != DB_TYPE_HEAP || error != HA_ERR_RECORD_FILE_FULL)
  {
    table->file->print_error(error,MYF(0));
    DBUG_RETURN(1);
  }
  new_table= *table;
  new_table.db_type=DB_TYPE_MYISAM;
  if (!(new_table.file=get_new_handler(&new_table,DB_TYPE_MYISAM)))
    DBUG_RETURN(1);				// End of memory

  save_proc_info=thd->proc_info;
  thd->proc_info="converting HEAP to MyISAM";

  if (create_myisam_tmp_table(&new_table,param,
5985
			      thd->lex->select_lex.options | thd->options))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5986 5987 5988
    goto err2;
  if (open_tmp_table(&new_table))
    goto err1;
5989 5990
  if (table->file->indexes_are_disabled())
    new_table.file->disable_indexes(HA_KEY_SWITCH_ALL);
5991
  table->file->ha_index_or_rnd_end();
5992
  table->file->ha_rnd_init(1);
5993 5994
  if (table->no_rows)
  {
5995 5996
    new_table.file->extra(HA_EXTRA_NO_ROWS);
    new_table.no_rows=1;
5997 5998
  }

5999 6000 6001 6002 6003 6004 6005 6006
#ifdef TO_BE_DONE_LATER_IN_4_1
  /*
    To use start_bulk_insert() (which is new in 4.1) we need to find
    all places where a corresponding end_bulk_insert() should be put.
  */
  table->file->info(HA_STATUS_VARIABLE); /* update table->file->records */
  new_table.file->start_bulk_insert(table->file->records);
#else
monty@mysql.com's avatar
monty@mysql.com committed
6007
  /* HA_EXTRA_WRITE_CACHE can stay until close, no need to disable it */
6008 6009 6010
  new_table.file->extra(HA_EXTRA_WRITE_CACHE);
#endif

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6011 6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022 6023 6024 6025
  /* copy all old rows */
  while (!table->file->rnd_next(new_table.record[1]))
  {
    if ((write_err=new_table.file->write_row(new_table.record[1])))
      goto err;
  }
  /* copy row that filled HEAP table */
  if ((write_err=new_table.file->write_row(table->record[0])))
  {
    if (write_err != HA_ERR_FOUND_DUPP_KEY &&
	write_err != HA_ERR_FOUND_DUPP_UNIQUE || !ignore_last_dupp_key_error)
    goto err;
  }

  /* remove heap table and change to use myisam table */
6026
  (void) table->file->ha_rnd_end();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6027 6028 6029 6030 6031 6032
  (void) table->file->close();
  (void) table->file->delete_table(table->real_name);
  delete table->file;
  table->file=0;
  *table =new_table;
  table->file->change_table_ptr(table);
6033 6034
  thd->proc_info= (!strcmp(save_proc_info,"Copying to tmp table") ?
		   "Copying to tmp table on disk" : save_proc_info);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6035 6036 6037 6038 6039
  DBUG_RETURN(0);

 err:
  DBUG_PRINT("error",("Got error: %d",write_err));
  table->file->print_error(error,MYF(0));	// Give table is full error
6040
  (void) table->file->ha_rnd_end();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6041 6042 6043 6044 6045 6046 6047 6048 6049 6050
  (void) new_table.file->close();
 err1:
  new_table.file->delete_table(new_table.real_name);
  delete new_table.file;
 err2:
  thd->proc_info=save_proc_info;
  DBUG_RETURN(1);
}


6051 6052 6053 6054 6055 6056
/****************************************************************************
  Make a join of all tables and write it on socket or to table
  Return:  0 if ok
           1 if error is sent
          -1 if error should be sent
****************************************************************************/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6057 6058 6059 6060

static int
do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
{
6061
  int error= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6062 6063 6064
  JOIN_TAB *join_tab;
  int (*end_select)(JOIN *, struct st_join_table *,bool);
  DBUG_ENTER("do_select");
6065
  List<Item> *columns_list= procedure ? &join->procedure_fields_list : fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6066 6067
  join->procedure=procedure;
  /*
6068
    Tell the client how many fields there are in a row
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6069 6070
  */
  if (!table)
6071
    join->result->send_fields(*columns_list, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6072 6073 6074 6075 6076
  else
  {
    VOID(table->file->extra(HA_EXTRA_WRITE_CACHE));
    empty_record(table);
  }
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6077
  join->tmp_table= table;			/* Save for easy recursion */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6078 6079 6080 6081 6082 6083 6084 6085 6086
  join->fields= fields;

  /* Set up select_end */
  if (table)
  {
    if (table->group && join->tmp_table_param.sum_func_count)
    {
      if (table->keys)
      {
6087
	DBUG_PRINT("info",("Using end_update"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6088
	end_select=end_update;
6089 6090
        if (!table->file->inited)
          table->file->ha_index_init(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6091 6092
      }
      else
6093 6094
      {
	DBUG_PRINT("info",("Using end_unique_update"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6095
	end_select=end_unique_update;
6096
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6097 6098 6099 6100 6101 6102 6103 6104 6105 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116
    }
    else if (join->sort_and_group)
    {
      DBUG_PRINT("info",("Using end_write_group"));
      end_select=end_write_group;
    }
    else
    {
      DBUG_PRINT("info",("Using end_write"));
      end_select=end_write;
    }
  }
  else
  {
    if (join->sort_and_group || (join->procedure &&
				 join->procedure->flags & PROC_GROUP))
      end_select=end_send_group;
    else
      end_select=end_send;
  }
6117 6118 6119
  if (join->tables)
  {
    join->join_tab[join->tables-1].next_select=end_select;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6120

6121 6122
    join_tab=join->join_tab+join->const_tables;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6123 6124 6125
  join->send_records=0;
  if (join->tables == join->const_tables)
  {
6126 6127 6128 6129
    /*
      HAVING will be chcked after processing aggregate functions,
      But WHERE should checkd here (we alredy have read tables)
    */
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
6130
    if (!join->conds || join->conds->val_int())
6131
    {
6132 6133
      if (!(error=(*end_select)(join,join_tab,0)) || error == -3)
	error=(*end_select)(join,join_tab,1);
6134
    }
6135
    else if (join->send_row_on_empty_set())
6136
      error= join->result->send_data(*columns_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6137 6138 6139
  }
  else
  {
6140
    DBUG_ASSERT(join_tab);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6141
    error= sub_select(join,join_tab,0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6142
    if (error >= 0)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6143
      error= sub_select(join,join_tab,1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6144
    if (error == -3)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6145
      error= 0;					/* select_limit used */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6146
  }
6147

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6148
  if (error >= 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6149
  {
6150 6151
    error=0;
    if (!table)					// If sending data to client
6152
    {
6153
      /*
6154 6155
	The following will unlock all cursors if the command wasn't an
	update command
6156
      */
6157
      join->join_free(0);				// Unlock all cursors
6158
      if (join->result->send_eof())
6159
	error= 1;				// Don't send error
6160
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6161 6162 6163 6164
    DBUG_PRINT("info",("%ld records output",join->send_records));
  }
  if (table)
  {
6165
    int tmp, new_errno= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6166 6167
    if ((tmp=table->file->extra(HA_EXTRA_NO_CACHE)))
    {
6168
      DBUG_PRINT("error",("extra(HA_EXTRA_NO_CACHE) failed"));
6169
      new_errno= tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6170
    }
6171
    if ((tmp=table->file->ha_index_or_rnd_end()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6172
    {
6173
      DBUG_PRINT("error",("ha_index_or_rnd_end() failed"));
6174
      new_errno= tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6175
    }
6176 6177
    if (new_errno)
      table->file->print_error(new_errno,MYF(0));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6178
  }
6179 6180 6181 6182 6183 6184
#ifndef DBUG_OFF
  if (error)
  {
    DBUG_PRINT("error",("Error: do_select() failed"));
  }
#endif
6185
  DBUG_RETURN(join->thd->net.report_error ? -1 : error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6186 6187 6188 6189 6190 6191 6192 6193 6194 6195 6196 6197 6198 6199
}


static int
sub_select_cache(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
{
  int error;

  if (end_of_records)
  {
    if ((error=flush_cached_records(join,join_tab,FALSE)) < 0)
      return error; /* purecov: inspected */
    return sub_select(join,join_tab,end_of_records);
  }
6200 6201 6202 6203 6204
  if (join->thd->killed)		// If aborted by user
  {
    my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
    return -2;				 /* purecov: inspected */
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6205 6206 6207 6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228
  if (join_tab->use_quick != 2 || test_if_quick_select(join_tab) <= 0)
  {
    if (!store_record_in_cache(&join_tab->cache))
      return 0;					// There is more room in cache
    return flush_cached_records(join,join_tab,FALSE);
  }
  if ((error=flush_cached_records(join,join_tab,TRUE)) < 0)
    return error; /* purecov: inspected */
  return sub_select(join,join_tab,end_of_records); /* Use ordinary select */
}


static int
sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
{

  join_tab->table->null_row=0;
  if (end_of_records)
    return (*join_tab->next_select)(join,join_tab+1,end_of_records);

  /* Cache variables for faster loop */
  int error;
  bool found=0;
  COND *on_expr=join_tab->on_expr, *select_cond=join_tab->select_cond;
6229
  my_bool *report_error= &(join->thd->net.report_error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6230 6231 6232

  if (!(error=(*join_tab->read_first_record)(join_tab)))
  {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6233 6234 6235
    bool not_exists_optimize= join_tab->table->reginfo.not_exists_optimize;
    bool not_used_in_distinct=join_tab->not_used_in_distinct;
    ha_rows found_records=join->found_records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6236 6237
    READ_RECORD *info= &join_tab->read_record;

6238
    join->thd->row_count= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6239 6240 6241 6242 6243 6244 6245
    do
    {
      if (join->thd->killed)			// Aborted by user
      {
	my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
	return -2;				/* purecov: inspected */
      }
6246
      join->examined_rows++;
6247 6248
      DBUG_PRINT("counts", ("join->examined_rows++: %lu",
                            (ulong) join->examined_rows));
6249
      join->thd->row_count++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6250 6251 6252 6253 6254 6255 6256
      if (!on_expr || on_expr->val_int())
      {
	found=1;
	if (not_exists_optimize)
	  break;			// Searching after not null columns
	if (!select_cond || select_cond->val_int())
	{
6257
	  if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6258
	    return error;
6259 6260 6261 6262 6263
	  /*
	    Test if this was a SELECT DISTINCT query on a table that
	    was not in the field list;  In this case we can abort if
	    we found a row, as no new rows can be added to the result.
	  */
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6264 6265
	  if (not_used_in_distinct && found_records != join->found_records)
	    return 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6266
	}
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6267
	else
6268 6269 6270 6271 6272 6273 6274
        {
          /* 
            This row failed selection, release lock on it.
            XXX: There is no table handler in MySQL which makes use of this
            call. It's kept from Gemini times. A lot of new code was added
            recently (i. e. subselects) without having it in mind.
          */
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6275
	  info->file->unlock_row();
6276
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6277
      }
6278
    } while (!(error=info->read_record(info)) && !(*report_error));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6279
  }
6280
  if (error > 0 || (*report_error))				// Fatal error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6281 6282 6283 6284
    return -1;

  if (!found && on_expr)
  {						// OUTER JOIN
6285
    restore_record(join_tab->table,default_values);		// Make empty record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6286 6287 6288
    mark_as_null_row(join_tab->table);		// For group by without error
    if (!select_cond || select_cond->val_int())
    {
6289
      if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6290 6291 6292 6293 6294 6295 6296 6297
	return error;				/* purecov: inspected */
    }
  }
  return 0;
}


static int
6298
flush_cached_records(JOIN *join,JOIN_TAB *join_tab,bool skip_last)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6299 6300 6301 6302 6303 6304
{
  int error;
  READ_RECORD *info;

  if (!join_tab->cache.records)
    return 0;				/* Nothing to do */
6305
  if (skip_last)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6306 6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317
    (void) store_record_in_cache(&join_tab->cache); // Must save this for later
  if (join_tab->use_quick == 2)
  {
    if (join_tab->select->quick)
    {					/* Used quick select last. reset it */
      delete join_tab->select->quick;
      join_tab->select->quick=0;
    }
  }
 /* read through all records */
  if ((error=join_init_read_record(join_tab)))
  {
6318
    reset_cache_write(&join_tab->cache);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337
    return -error;			/* No records or error */
  }

  for (JOIN_TAB *tmp=join->join_tab; tmp != join_tab ; tmp++)
  {
    tmp->status=tmp->table->status;
    tmp->table->status=0;
  }

  info= &join_tab->read_record;
  do
  {
    if (join->thd->killed)
    {
      my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
      return -2;				// Aborted by user /* purecov: inspected */
    }
    SQL_SELECT *select=join_tab->select;
    if (!error && (!join_tab->cache.select ||
6338
		   !join_tab->cache.select->skip_record()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6339 6340
    {
      uint i;
6341
      reset_cache_read(&join_tab->cache);
6342
      for (i=(join_tab->cache.records- (skip_last ? 1 : 0)) ; i-- > 0 ;)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6343 6344
      {
	read_cached_record(join_tab);
6345
	if (!select || !select->skip_record())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6346
	  if ((error=(join_tab->next_select)(join,join_tab+1,0)) < 0)
6347 6348
          {
            reset_cache_write(&join_tab->cache);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6349
	    return error; /* purecov: inspected */
6350
          }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6351 6352 6353 6354
      }
    }
  } while (!(error=info->read_record(info)));

6355
  if (skip_last)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6356
    read_cached_record(join_tab);		// Restore current record
6357
  reset_cache_write(&join_tab->cache);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6358 6359 6360 6361 6362 6363 6364 6365 6366
  if (error > 0)				// Fatal error
    return -1;					/* purecov: inspected */
  for (JOIN_TAB *tmp2=join->join_tab; tmp2 != join_tab ; tmp2++)
    tmp2->table->status=tmp2->status;
  return 0;
}


/*****************************************************************************
6367 6368
  The different ways to read a record
  Returns -1 if row was not found, 0 if row was found and 1 on errors
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6369
*****************************************************************************/
6370 6371 6372

/* Help function when we get some an error from the table handler */

6373
int report_error(TABLE *table, int error)
6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391
{
  if (error == HA_ERR_END_OF_FILE || error == HA_ERR_KEY_NOT_FOUND)
  {
    table->status= STATUS_GARBAGE;
    return -1;					// key not found; ok
  }
  /*
    Locking reads can legally return also these errors, do not
    print them to the .err log
  */
  if (error != HA_ERR_LOCK_DEADLOCK && error != HA_ERR_LOCK_WAIT_TIMEOUT)
    sql_print_error("Got error %d when reading table '%s'",
		    error, table->path);
  table->file->print_error(error,MYF(0));
  return 1;
}


6392
int safe_index_read(JOIN_TAB *tab)
6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403
{
  int error;
  TABLE *table= tab->table;
  if ((error=table->file->index_read(table->record[0],
				     tab->ref.key_buff,
				     tab->ref.key_length, HA_READ_KEY_EXACT)))
    return report_error(table, error);
  return 0;
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
6404
static int
6405
join_read_const_table(JOIN_TAB *tab, POSITION *pos)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6406 6407
{
  int error;
6408 6409 6410 6411 6412 6413 6414
  DBUG_ENTER("join_read_const_table");
  TABLE *table=tab->table;
  table->const_table=1;
  table->null_row=0;
  table->status=STATUS_NO_RECORD;
  
  if (tab->type == JT_SYSTEM)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6415
  {
6416 6417 6418 6419 6420 6421 6422
    if ((error=join_read_system(tab)))
    {						// Info for DESCRIBE
      tab->info="const row not found";
      /* Mark for EXPLAIN that the row was not found */
      pos->records_read=0.0;
      if (!table->outer_join || error > 0)
	DBUG_RETURN(error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6423
    }
6424 6425 6426
  }
  else
  {
6427
    if (!table->key_read && table->used_keys.is_set(tab->ref.key) &&
6428 6429
	!table->no_keyread &&
        (int) table->reginfo.lock_type <= (int) TL_READ_HIGH_PRIORITY)
6430 6431 6432
    {
      table->key_read=1;
      table->file->extra(HA_EXTRA_KEYREAD);
6433
      tab->index= tab->ref.key;
6434
    }
6435
    if ((error=join_read_const(tab)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6436
    {
6437 6438 6439 6440 6441
      tab->info="unique row not found";
      /* Mark for EXPLAIN that the row was not found */
      pos->records_read=0.0;
      if (!table->outer_join || error > 0)
	DBUG_RETURN(error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6442
    }
6443 6444 6445 6446 6447
    if (table->key_read)
    {
      table->key_read=0;
      table->file->extra(HA_EXTRA_NO_KEYREAD);
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6448
  }
6449 6450 6451
  if (tab->on_expr && !table->null_row)
  {
    if ((table->null_row= test(tab->on_expr->val_int() == 0)))
6452 6453
      mark_as_null_row(table);  
  }
6454 6455
  if (!table->null_row)
    table->maybe_null=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6456 6457 6458 6459 6460 6461 6462 6463 6464 6465 6466
  DBUG_RETURN(0);
}


static int
join_read_system(JOIN_TAB *tab)
{
  TABLE *table= tab->table;
  int error;
  if (table->status & STATUS_GARBAGE)		// If first read
  {
6467 6468
    if ((error=table->file->read_first_row(table->record[0],
					   table->primary_key)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6469 6470
    {
      if (error != HA_ERR_END_OF_FILE)
6471
	return report_error(table, error);
6472
      mark_as_null_row(tab->table);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6473 6474 6475
      empty_record(table);			// Make empty record
      return -1;
    }
6476
    store_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6477 6478
  }
  else if (!table->status)			// Only happens with left join
6479
    restore_record(table,record[1]);			// restore old record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6480 6481 6482 6483 6484 6485 6486 6487 6488 6489 6490 6491
  table->null_row=0;
  return table->status ? -1 : 0;
}


static int
join_read_const(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;
  if (table->status & STATUS_GARBAGE)		// If first read
  {
sergefp@mysql.com's avatar
sergefp@mysql.com committed
6492
    if (cp_buffer_from_ref(tab->join->thd, &tab->ref))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6493 6494 6495 6496 6497 6498 6499 6500 6501
      error=HA_ERR_KEY_NOT_FOUND;
    else
    {
      error=table->file->index_read_idx(table->record[0],tab->ref.key,
					(byte*) tab->ref.key_buff,
					tab->ref.key_length,HA_READ_KEY_EXACT);
    }
    if (error)
    {
6502
      mark_as_null_row(tab->table);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6503 6504
      empty_record(table);
      if (error != HA_ERR_KEY_NOT_FOUND)
6505
	return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6506 6507
      return -1;
    }
6508
    store_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6509
  }
6510 6511 6512
  else if (!(table->status & ~STATUS_NULL_ROW))	// Only happens with left join
  {
    table->status=0;
6513
    restore_record(table,record[1]);			// restore old record
6514
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6515 6516 6517 6518 6519 6520 6521 6522 6523 6524 6525
  table->null_row=0;
  return table->status ? -1 : 0;
}


static int
join_read_key(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

6526 6527
  if (!table->file->inited)
    table->file->ha_index_init(tab->ref.key);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6528
  if (cmp_buffer_with_ref(tab) ||
6529
      (table->status & (STATUS_GARBAGE | STATUS_NO_PARENT | STATUS_NULL_ROW)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6530 6531 6532 6533 6534 6535 6536 6537 6538 6539
  {
    if (tab->ref.key_err)
    {
      table->status=STATUS_NOT_FOUND;
      return -1;
    }
    error=table->file->index_read(table->record[0],
				  tab->ref.key_buff,
				  tab->ref.key_length,HA_READ_KEY_EXACT);
    if (error && error != HA_ERR_KEY_NOT_FOUND)
6540
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6541
  }
6542
  table->null_row=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6543 6544 6545 6546 6547 6548 6549 6550 6551 6552
  return table->status ? -1 : 0;
}


static int
join_read_always_key(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
6553 6554 6555 6556 6557
  for (uint i= 0 ; i < tab->ref.key_parts ; i++)
  {
    if ((tab->ref.null_rejecting & 1 << i) && tab->ref.items[i]->is_null())
        return -1;
  } 
6558 6559
  if (!table->file->inited)
    table->file->ha_index_init(tab->ref.key);
sergefp@mysql.com's avatar
sergefp@mysql.com committed
6560
  if (cp_buffer_from_ref(tab->join->thd, &tab->ref))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6561 6562 6563 6564 6565 6566
    return -1;
  if ((error=table->file->index_read(table->record[0],
				     tab->ref.key_buff,
				     tab->ref.key_length,HA_READ_KEY_EXACT)))
  {
    if (error != HA_ERR_KEY_NOT_FOUND)
6567
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6568 6569 6570 6571 6572
    return -1; /* purecov: inspected */
  }
  return 0;
}

6573

6574 6575 6576 6577 6578 6579 6580 6581 6582 6583 6584
/*
  This function is used when optimizing away ORDER BY in 
  SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
*/
  
static int
join_read_last_key(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

6585 6586
  if (!table->file->inited)
    table->file->ha_index_init(tab->ref.key);
sergefp@mysql.com's avatar
sergefp@mysql.com committed
6587
  if (cp_buffer_from_ref(tab->join->thd, &tab->ref))
6588 6589 6590 6591 6592 6593
    return -1;
  if ((error=table->file->index_read_last(table->record[0],
					  tab->ref.key_buff,
					  tab->ref.key_length)))
  {
    if (error != HA_ERR_KEY_NOT_FOUND)
6594
      return report_error(table, error);
6595 6596 6597 6598 6599
    return -1; /* purecov: inspected */
  }
  return 0;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6600 6601 6602 6603 6604 6605 6606 6607 6608 6609

	/* ARGSUSED */
static int
join_no_more_records(READ_RECORD *info __attribute__((unused)))
{
  return -1;
}


static int
6610
join_read_next_same(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6611 6612 6613 6614 6615 6616 6617 6618 6619 6620
{
  int error;
  TABLE *table= info->table;
  JOIN_TAB *tab=table->reginfo.join_tab;

  if ((error=table->file->index_next_same(table->record[0],
					  tab->ref.key_buff,
					  tab->ref.key_length)))
  {
    if (error != HA_ERR_END_OF_FILE)
6621
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6622 6623 6624 6625 6626 6627
    table->status= STATUS_GARBAGE;
    return -1;
  }
  return 0;
}

6628

6629 6630 6631 6632 6633 6634 6635 6636
static int
join_read_prev_same(READ_RECORD *info)
{
  int error;
  TABLE *table= info->table;
  JOIN_TAB *tab=table->reginfo.join_tab;

  if ((error=table->file->index_prev(table->record[0])))
6637
    return report_error(table, error);
6638 6639
  if (key_cmp_if_same(table, tab->ref.key_buff, tab->ref.key,
                      tab->ref.key_length))
6640 6641
  {
    table->status=STATUS_NOT_FOUND;
6642
    error= -1;
6643 6644 6645 6646
  }
  return error;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6647 6648 6649 6650 6651 6652 6653 6654 6655 6656 6657 6658 6659 6660 6661

static int
join_init_quick_read_record(JOIN_TAB *tab)
{
  if (test_if_quick_select(tab) == -1)
    return -1;					/* No possible records */
  return join_init_read_record(tab);
}


static int
test_if_quick_select(JOIN_TAB *tab)
{
  delete tab->select->quick;
  tab->select->quick=0;
6662
  return tab->select->test_quick_select(tab->join->thd, tab->keys,
6663
					(table_map) 0, HA_POS_ERROR, 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6664 6665 6666 6667 6668 6669 6670 6671
}


static int
join_init_read_record(JOIN_TAB *tab)
{
  if (tab->select && tab->select->quick)
    tab->select->quick->reset();
6672 6673
  init_read_record(&tab->read_record, tab->join->thd, tab->table,
		   tab->select,1,1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6674 6675 6676
  return (*tab->read_record.read_record)(&tab->read_record);
}

6677

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6678
static int
6679
join_read_first(JOIN_TAB *tab)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6680 6681 6682
{
  int error;
  TABLE *table=tab->table;
6683
  if (!table->key_read && table->used_keys.is_set(tab->index) &&
6684
      !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6685 6686 6687 6688 6689
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
6690
  tab->read_record.read_record=join_read_next;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6691 6692 6693 6694
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
6695 6696
  if (!table->file->inited)
    table->file->ha_index_init(tab->index);
6697
  if ((error=tab->table->file->index_first(tab->table->record[0])))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6698 6699
  {
    if (error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE)
6700
      report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6701 6702 6703 6704 6705
    return -1;
  }
  return 0;
}

6706

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6707
static int
6708
join_read_next(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6709
{
6710 6711 6712
  int error;
  if ((error=info->file->index_next(info->record)))
    return report_error(info->table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6713 6714 6715
  return 0;
}

6716

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6717
static int
6718
join_read_last(JOIN_TAB *tab)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6719 6720 6721
{
  TABLE *table=tab->table;
  int error;
6722
  if (!table->key_read && table->used_keys.is_set(tab->index) &&
6723
      !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6724 6725 6726 6727 6728
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
6729
  tab->read_record.read_record=join_read_prev;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6730 6731 6732 6733
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
6734 6735
  if (!table->file->inited)
    table->file->ha_index_init(tab->index);
6736 6737
  if ((error= tab->table->file->index_last(tab->table->record[0])))
    return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6738 6739 6740
  return 0;
}

6741

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6742
static int
6743
join_read_prev(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6744
{
6745 6746 6747
  int error;
  if ((error= info->file->index_prev(info->record)))
    return report_error(info->table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6748 6749 6750
  return 0;
}

6751

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6752 6753 6754 6755 6756 6757
static int
join_ft_read_first(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

6758 6759
  if (!table->file->inited)
    table->file->ha_index_init(tab->ref.key);
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6760
#if NOT_USED_YET
sergefp@mysql.com's avatar
sergefp@mysql.com committed
6761
  if (cp_buffer_from_ref(tab->join->thd, &tab->ref)) // as ft-key doesn't use store_key's
6762
    return -1;                             // see also FT_SELECT::init()
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6763
#endif
6764
  table->file->ft_init();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6765

6766 6767
  if ((error= table->file->ft_read(table->record[0])))
    return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6768 6769 6770 6771 6772 6773
  return 0;
}

static int
join_ft_read_next(READ_RECORD *info)
{
6774 6775 6776
  int error;
  if ((error= info->file->ft_read(info->table->record[0])))
    return report_error(info->table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6777 6778 6779 6780
  return 0;
}


6781 6782 6783 6784 6785 6786 6787 6788 6789 6790
/*
  Reading of key with key reference and one part that may be NULL
*/

static int
join_read_always_key_or_null(JOIN_TAB *tab)
{
  int res;

  /* First read according to key which is NOT NULL */
6791
  *tab->ref.null_ref_key= 0;			// Clear null byte
6792 6793 6794 6795
  if ((res= join_read_always_key(tab)) >= 0)
    return res;

  /* Then read key with null value */
6796
  *tab->ref.null_ref_key= 1;			// Set null byte
6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809
  return safe_index_read(tab);
}


static int
join_read_next_same_or_null(READ_RECORD *info)
{
  int error;
  if ((error= join_read_next_same(info)) >= 0)
    return error;
  JOIN_TAB *tab= info->table->reginfo.join_tab;

  /* Test if we have already done a read after null key */
6810
  if (*tab->ref.null_ref_key)
6811
    return -1;					// All keys read
6812 6813
  *tab->ref.null_ref_key= 1;			// Set null byte
  return safe_index_read(tab);			// then read null keys
6814 6815 6816
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
6817
/*****************************************************************************
6818 6819 6820
  The different end of select functions
  These functions returns < 0 when end is reached, 0 on ok and > 0 if a
  fatal error (like table corruption) was detected
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6821 6822
*****************************************************************************/

6823
/* ARGSUSED */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6824 6825 6826 6827 6828 6829 6830 6831
static int
end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
	 bool end_of_records)
{
  DBUG_ENTER("end_send");
  if (!end_of_records)
  {
    int error;
6832
    if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6833
      DBUG_RETURN(0);				// Didn't match having
6834
    error=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6835
    if (join->procedure)
6836
      error=join->procedure->send_row(join->procedure_fields_list);
6837
    else if (join->do_send_rows)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6838 6839 6840
      error=join->result->send_data(*join->fields);
    if (error)
      DBUG_RETURN(-1); /* purecov: inspected */
6841
    if (++join->send_records >= join->unit->select_limit_cnt &&
6842
	join->do_send_rows)
6843 6844 6845
    {
      if (join->select_options & OPTION_FOUND_ROWS)
      {
6846
	JOIN_TAB *jt=join->join_tab;
6847
	if ((join->tables == 1) && !join->tmp_table && !join->sort_and_group
6848
	    && !join->send_group_parts && !join->having && !jt->select_cond &&
6849
	    !(jt->select && jt->select->quick) &&
ram@gw.mysql.r18.ru's avatar
ram@gw.mysql.r18.ru committed
6850 6851
	    !(jt->table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
            (jt->ref.key < 0))
6852
	{
6853
	  /* Join over all rows in table;  Return number of found rows */
6854 6855
	  TABLE *table=jt->table;

6856
	  join->select_options ^= OPTION_FOUND_ROWS;
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
6857 6858
	  if (table->sort.record_pointers ||
	      (table->sort.io_cache && my_b_inited(table->sort.io_cache)))
6859 6860
	  {
	    /* Using filesort */
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
6861
	    join->send_records= table->sort.found_records;
6862 6863 6864 6865 6866 6867
	  }
	  else
	  {
	    table->file->info(HA_STATUS_VARIABLE);
	    join->send_records = table->file->records;
	  }
6868 6869 6870
	}
	else 
	{
6871
	  join->do_send_rows= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
6872 6873
	  if (join->unit->fake_select_lex)
	    join->unit->fake_select_lex->select_limit= HA_POS_ERROR;
6874 6875
	  DBUG_RETURN(0);
	}
6876
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6877
      DBUG_RETURN(-3);				// Abort nicely
6878
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6879 6880 6881 6882 6883 6884 6885 6886 6887 6888 6889 6890 6891 6892 6893 6894 6895 6896 6897 6898 6899
  }
  else
  {
    if (join->procedure && join->procedure->end_of_records())
      DBUG_RETURN(-1);
  }
  DBUG_RETURN(0);
}


	/* ARGSUSED */
static int
end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
	       bool end_of_records)
{
  int idx= -1;
  DBUG_ENTER("end_send_group");

  if (!join->first_record || end_of_records ||
      (idx=test_if_group_changed(join->group_fields)) >= 0)
  {
6900 6901
    if (join->first_record || 
        (end_of_records && !join->group && !join->group_optimized_away))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6902 6903 6904 6905 6906
    {
      if (join->procedure)
	join->procedure->end_group();
      if (idx < (int) join->send_group_parts)
      {
6907
	int error=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6908 6909
	if (join->procedure)
	{
6910
	  if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6911
	    error= -1;				// Didn't satisfy having
6912 6913 6914 6915 6916 6917
 	  else
	  {
	    if (join->do_send_rows)
	      error=join->procedure->send_row(*join->fields) ? 1 : 0;
	    join->send_records++;
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6918 6919 6920 6921 6922 6923
	  if (end_of_records && join->procedure->end_of_records())
	    error= 1;				// Fatal error
	}
	else
	{
	  if (!join->first_record)
6924
	  {
6925 6926
            List_iterator_fast<Item> it(*join->fields);
            Item *item;
6927
	    /* No matching rows for group function */
6928
	    join->clear();
6929 6930 6931

            while ((item= it++))
              item->no_rows_in_result();
6932
	  }
6933
	  if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6934
	    error= -1;				// Didn't satisfy having
6935 6936 6937 6938 6939 6940 6941 6942 6943 6944 6945
	  else
	  {
	    if (join->do_send_rows)
	      error=join->result->send_data(*join->fields) ? 1 : 0;
	    join->send_records++;
	  }
	  if (join->rollup.state != ROLLUP::STATE_NONE && error <= 0)
	  {
	    if (join->rollup_send_data((uint) (idx+1)))
	      error= 1;
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6946 6947 6948
	}
	if (error > 0)
	  DBUG_RETURN(-1);			/* purecov: inspected */
6949 6950
	if (end_of_records)
	  DBUG_RETURN(0);
6951
	if (join->send_records >= join->unit->select_limit_cnt &&
6952 6953 6954 6955 6956
	    join->do_send_rows)
	{
	  if (!(join->select_options & OPTION_FOUND_ROWS))
	    DBUG_RETURN(-3);				// Abort nicely
	  join->do_send_rows=0;
6957
	  join->unit->select_limit_cnt = HA_POS_ERROR;
6958
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6959 6960 6961 6962 6963 6964 6965 6966 6967 6968 6969 6970
      }
    }
    else
    {
      if (end_of_records)
	DBUG_RETURN(0);
      join->first_record=1;
      VOID(test_if_group_changed(join->group_fields));
    }
    if (idx < (int) join->send_group_parts)
    {
      copy_fields(&join->tmp_table_param);
6971 6972
      if (init_sum_functions(join->sum_funcs, join->sum_funcs_end[idx+1]))
	DBUG_RETURN(-1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6973 6974 6975 6976 6977 6978 6979 6980 6981 6982 6983 6984 6985 6986 6987 6988 6989 6990 6991 6992 6993 6994 6995 6996 6997 6998 6999 7000 7001 7002
      if (join->procedure)
	join->procedure->add();
      DBUG_RETURN(0);
    }
  }
  if (update_sum_func(join->sum_funcs))
    DBUG_RETURN(-1);
  if (join->procedure)
    join->procedure->add();
  DBUG_RETURN(0);
}


	/* ARGSUSED */
static int
end_write(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
	  bool end_of_records)
{
  TABLE *table=join->tmp_table;
  int error;
  DBUG_ENTER("end_write");

  if (join->thd->killed)			// Aborted by user
  {
    my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
    DBUG_RETURN(-2);				/* purecov: inspected */
  }
  if (!end_of_records)
  {
    copy_fields(&join->tmp_table_param);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7003
    copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7004

7005
#ifdef TO_BE_DELETED
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7006 7007 7008 7009 7010 7011 7012 7013 7014
    if (!table->uniques)			// If not unique handling
    {
      /* Copy null values from group to row */
      ORDER   *group;
      for (group=table->group ; group ; group=group->next)
      {
	Item *item= *group->item;
	if (item->maybe_null)
	{
7015
	  Field *field=item->get_tmp_table_field();
7016
	  field->ptr[-1]= (byte) (field->is_null() ? 1 : 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7017 7018 7019
	}
      }
    }
7020
#endif
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7021 7022
    if (!join->having || join->having->val_int())
    {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
7023
      join->found_records++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7024 7025
      if ((error=table->file->write_row(table->record[0])))
      {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
7026 7027 7028
	if (error == HA_ERR_FOUND_DUPP_KEY ||
	    error == HA_ERR_FOUND_DUPP_UNIQUE)
	  goto end;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7029 7030
	if (create_myisam_from_heap(join->thd, table, &join->tmp_table_param,
				    error,1))
7031
	  DBUG_RETURN(-1);			// Not a table_is_full error
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
7032
	table->uniques=0;			// To ensure rows are the same
7033
      }
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
7034
      if (++join->send_records >= join->tmp_table_param.end_write_records &&
7035 7036 7037 7038 7039
	  join->do_send_rows)
      {
	if (!(join->select_options & OPTION_FOUND_ROWS))
	  DBUG_RETURN(-3);
	join->do_send_rows=0;
7040
	join->unit->select_limit_cnt = HA_POS_ERROR;
7041
	DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7042 7043 7044
      }
    }
  }
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
7045
end:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7046 7047 7048 7049 7050 7051 7052 7053 7054 7055 7056 7057 7058 7059 7060 7061 7062 7063 7064 7065 7066 7067 7068
  DBUG_RETURN(0);
}

/* Group by searching after group record and updating it if possible */
/* ARGSUSED */

static int
end_update(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
	   bool end_of_records)
{
  TABLE *table=join->tmp_table;
  ORDER   *group;
  int	  error;
  DBUG_ENTER("end_update");

  if (end_of_records)
    DBUG_RETURN(0);
  if (join->thd->killed)			// Aborted by user
  {
    my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
    DBUG_RETURN(-2);				/* purecov: inspected */
  }

monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
7069
  join->found_records++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7070 7071 7072 7073 7074 7075
  copy_fields(&join->tmp_table_param);		// Groups are copied twice.
  /* Make a key of group index */
  for (group=table->group ; group ; group=group->next)
  {
    Item *item= *group->item;
    item->save_org_in_field(group->field);
hf@bisonxp.(none)'s avatar
hf@bisonxp.(none) committed
7076 7077 7078
#ifdef EMBEDDED_LIBRARY
    join->thd->net.last_errno= 0;
#endif
7079
    /* Store in the used key if the field was 0 */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7080
    if (item->maybe_null)
7081
      group->buff[-1]=item->null_value ? 1 : 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7082 7083 7084 7085 7086
  }
  if (!table->file->index_read(table->record[1],
			       join->tmp_table_param.group_buff,0,
			       HA_READ_KEY_EXACT))
  {						/* Update old record */
7087
    restore_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7088 7089 7090 7091 7092 7093 7094 7095 7096 7097 7098 7099 7100 7101 7102 7103 7104 7105
    update_tmptable_sum_func(join->sum_funcs,table);
    if ((error=table->file->update_row(table->record[1],
				       table->record[0])))
    {
      table->file->print_error(error,MYF(0));	/* purecov: inspected */
      DBUG_RETURN(-1);				/* purecov: inspected */
    }
    DBUG_RETURN(0);
  }

  /* The null bits are already set */
  KEY_PART_INFO *key_part;
  for (group=table->group,key_part=table->key_info[0].key_part;
       group ;
       group=group->next,key_part++)
    memcpy(table->record[0]+key_part->offset, group->buff, key_part->length);

  init_tmptable_sum_functions(join->sum_funcs);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7106
  copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7107 7108
  if ((error=table->file->write_row(table->record[0])))
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7109 7110
    if (create_myisam_from_heap(join->thd, table, &join->tmp_table_param,
				error, 0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7111 7112
      DBUG_RETURN(-1);				// Not a table_is_full error
    /* Change method to update rows */
7113
    table->file->ha_index_init(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7114 7115 7116 7117 7118 7119 7120 7121 7122 7123 7124 7125 7126 7127 7128 7129 7130 7131 7132 7133 7134 7135 7136 7137 7138 7139
    join->join_tab[join->tables-1].next_select=end_unique_update;
  }
  join->send_records++;
  DBUG_RETURN(0);
}

/* Like end_update, but this is done with unique constraints instead of keys */

static int
end_unique_update(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
		  bool end_of_records)
{
  TABLE *table=join->tmp_table;
  int	  error;
  DBUG_ENTER("end_unique_update");

  if (end_of_records)
    DBUG_RETURN(0);
  if (join->thd->killed)			// Aborted by user
  {
    my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
    DBUG_RETURN(-2);				/* purecov: inspected */
  }

  init_tmptable_sum_functions(join->sum_funcs);
  copy_fields(&join->tmp_table_param);		// Groups are copied twice.
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7140
  copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7141 7142 7143 7144 7145 7146 7147 7148 7149 7150 7151 7152 7153 7154 7155

  if (!(error=table->file->write_row(table->record[0])))
    join->send_records++;			// New group
  else
  {
    if ((int) table->file->get_dup_key(error) < 0)
    {
      table->file->print_error(error,MYF(0));	/* purecov: inspected */
      DBUG_RETURN(-1);				/* purecov: inspected */
    }
    if (table->file->rnd_pos(table->record[1],table->file->dupp_ref))
    {
      table->file->print_error(error,MYF(0));	/* purecov: inspected */
      DBUG_RETURN(-1);				/* purecov: inspected */
    }
7156
    restore_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7157 7158 7159 7160 7161 7162 7163 7164 7165 7166 7167 7168 7169 7170 7171 7172 7173 7174 7175 7176 7177 7178 7179 7180 7181 7182 7183 7184 7185 7186 7187 7188 7189 7190
    update_tmptable_sum_func(join->sum_funcs,table);
    if ((error=table->file->update_row(table->record[1],
				       table->record[0])))
    {
      table->file->print_error(error,MYF(0));	/* purecov: inspected */
      DBUG_RETURN(-1);				/* purecov: inspected */
    }
  }
  DBUG_RETURN(0);
}


	/* ARGSUSED */
static int
end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
		bool end_of_records)
{
  TABLE *table=join->tmp_table;
  int	  error;
  int	  idx= -1;
  DBUG_ENTER("end_write_group");

  if (join->thd->killed)
  {						// Aborted by user
    my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
    DBUG_RETURN(-2);				/* purecov: inspected */
  }
  if (!join->first_record || end_of_records ||
      (idx=test_if_group_changed(join->group_fields)) >= 0)
  {
    if (join->first_record || (end_of_records && !join->group))
    {
      if (join->procedure)
	join->procedure->end_group();
7191 7192
      int send_group_parts= join->send_group_parts;
      if (idx < send_group_parts)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7193 7194
      {
	if (!join->first_record)
7195 7196
	{
	  /* No matching rows for group function */
7197
	  join->clear();
7198
	}
7199 7200 7201 7202 7203
        copy_sum_funcs(join->sum_funcs,
                       join->sum_funcs_end[send_group_parts]);
	if (join->having && join->having->val_int() == 0)
          error= -1;
        else if ((error=table->file->write_row(table->record[0])))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7204
	{
7205 7206 7207 7208
	  if (create_myisam_from_heap(join->thd, table,
				      &join->tmp_table_param,
				      error, 0))
	    DBUG_RETURN(-1);		       
7209 7210 7211 7212 7213
            /* 
              If table->file->write_row() was failed because of 'out of memory'
              and tmp table succesfully created, reset error.
             */
            error=0;
7214 7215 7216 7217 7218
        }
        if (join->rollup.state != ROLLUP::STATE_NONE && error <= 0)
	{
	  if (join->rollup_write_data((uint) (idx+1), table))
	    error= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7219
	}
7220 7221
	if (error > 0)
	  DBUG_RETURN(-1);	  
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7222 7223 7224 7225 7226 7227
	if (end_of_records)
	  DBUG_RETURN(0);
      }
    }
    else
    {
7228 7229
      if (end_of_records)
	DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7230 7231 7232 7233 7234 7235
      join->first_record=1;
      VOID(test_if_group_changed(join->group_fields));
    }
    if (idx < (int) join->send_group_parts)
    {
      copy_fields(&join->tmp_table_param);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7236
      copy_funcs(join->tmp_table_param.items_to_copy);
7237 7238
      if (init_sum_functions(join->sum_funcs, join->sum_funcs_end[idx+1]))
	DBUG_RETURN(-1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7239 7240 7241 7242 7243 7244 7245 7246 7247 7248 7249 7250 7251 7252
      if (join->procedure)
	join->procedure->add();
      DBUG_RETURN(0);
    }
  }
  if (update_sum_func(join->sum_funcs))
    DBUG_RETURN(-1);
  if (join->procedure)
    join->procedure->add();
  DBUG_RETURN(0);
}


/*****************************************************************************
7253 7254 7255 7256 7257
  Remove calculation with tables that aren't yet read. Remove also tests
  against fields that are read through key where the table is not a
  outer join table.
  We can't remove tests that are made against columns which are stored
  in sorted order.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7258 7259 7260 7261 7262 7263 7264
*****************************************************************************/

/* Return 1 if right_item is used removable reference key on left_item */

static bool test_if_ref(Item_field *left_item,Item *right_item)
{
  Field *field=left_item->field;
7265 7266
  // No need to change const test. We also have to keep tests on LEFT JOIN
  if (!field->table->const_table && !field->table->maybe_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7267 7268
  {
    Item *ref_item=part_of_refkey(field->table,field);
7269
    if (ref_item && ref_item->eq(right_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7270 7271
    {
      if (right_item->type() == Item::FIELD_ITEM)
7272 7273
	return (field->eq_def(((Item_field *) right_item)->field));
      if (right_item->const_item() && !(right_item->is_null()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7274
      {
7275 7276 7277
	/*
	  We can remove binary fields and numerical fields except float,
	  as float comparison isn't 100 % secure
monty@mysql.com's avatar
monty@mysql.com committed
7278
	  We have to keep binary strings to be able to check for end spaces
7279
	*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7280
	if (field->binary() &&
monty@mysql.com's avatar
monty@mysql.com committed
7281 7282
	    field->real_type() != FIELD_TYPE_STRING &&
	    field->real_type() != FIELD_TYPE_VAR_STRING &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7283 7284
	    (field->type() != FIELD_TYPE_FLOAT || field->decimals() == 0))
	{
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
7285
	  return !store_val_in_field(field, right_item, CHECK_FIELD_WARN);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7286 7287 7288 7289 7290 7291 7292 7293 7294
	}
      }
    }
  }
  return 0;					// keep test
}


static COND *
7295
make_cond_for_table(COND *cond, table_map tables, table_map used_table)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7296 7297 7298 7299 7300 7301 7302
{
  if (used_table && !(cond->used_tables() & used_table))
    return (COND*) 0;				// Already checked
  if (cond->type() == Item::COND_ITEM)
  {
    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
7303
      /* Create new top level AND item */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7304 7305 7306 7307 7308 7309 7310 7311 7312 7313 7314 7315 7316 7317 7318 7319 7320
      Item_cond_and *new_cond=new Item_cond_and;
      if (!new_cond)
	return (COND*) 0;			// OOM /* purecov: inspected */
      List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
      Item *item;
      while ((item=li++))
      {
	Item *fix=make_cond_for_table(item,tables,used_table);
	if (fix)
	  new_cond->argument_list()->push_back(fix);
      }
      switch (new_cond->argument_list()->elements) {
      case 0:
	return (COND*) 0;			// Always true
      case 1:
	return new_cond->argument_list()->head();
      default:
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
7321 7322 7323 7324 7325 7326 7327 7328
	/*
	  Item_cond_and do not need fix_fields for execution, its parameters
	  are fixed or do not need fix_fields, too
	*/
	new_cond->quick_fix_field();
	new_cond->used_tables_cache=
	  ((Item_cond_and*) cond)->used_tables_cache &
	  tables;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7329 7330 7331 7332 7333 7334 7335 7336 7337 7338 7339 7340 7341 7342 7343 7344 7345
	return new_cond;
      }
    }
    else
    {						// Or list
      Item_cond_or *new_cond=new Item_cond_or;
      if (!new_cond)
	return (COND*) 0;			// OOM /* purecov: inspected */
      List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
      Item *item;
      while ((item=li++))
      {
	Item *fix=make_cond_for_table(item,tables,0L);
	if (!fix)
	  return (COND*) 0;			// Always true
	new_cond->argument_list()->push_back(fix);
      }
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
7346 7347 7348 7349 7350 7351
      /*
	Item_cond_and do not need fix_fields for execution, its parameters
	are fixed or do not need fix_fields, too
      */
      new_cond->quick_fix_field();
      new_cond->used_tables_cache= ((Item_cond_or*) cond)->used_tables_cache;
7352
      new_cond->top_level_item();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7353 7354 7355 7356 7357
      return new_cond;
    }
  }

  /*
7358 7359 7360
    Because the following test takes a while and it can be done
    table_count times, we mark each item that we have examined with the result
    of the test
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7361 7362 7363 7364 7365 7366 7367 7368 7369 7370 7371 7372 7373 7374 7375 7376 7377 7378 7379 7380 7381 7382 7383 7384 7385 7386 7387 7388 7389 7390 7391
  */

  if (cond->marker == 3 || (cond->used_tables() & ~tables))
    return (COND*) 0;				// Can't check this yet
  if (cond->marker == 2 || cond->eq_cmp_result() == Item::COND_OK)
    return cond;				// Not boolean op

  if (((Item_func*) cond)->functype() == Item_func::EQ_FUNC)
  {
    Item *left_item=	((Item_func*) cond)->arguments()[0];
    Item *right_item= ((Item_func*) cond)->arguments()[1];
    if (left_item->type() == Item::FIELD_ITEM &&
	test_if_ref((Item_field*) left_item,right_item))
    {
      cond->marker=3;			// Checked when read
      return (COND*) 0;
    }
    if (right_item->type() == Item::FIELD_ITEM &&
	test_if_ref((Item_field*) right_item,left_item))
    {
      cond->marker=3;			// Checked when read
      return (COND*) 0;
    }
  }
  cond->marker=2;
  return cond;
}

static Item *
part_of_refkey(TABLE *table,Field *field)
{
7392 7393 7394
  if (!table->reginfo.join_tab)
    return (Item*) 0;             // field from outer non-select (UPDATE,...)

bk@work.mysql.com's avatar
bk@work.mysql.com committed
7395 7396 7397 7398 7399 7400 7401 7402
  uint ref_parts=table->reginfo.join_tab->ref.key_parts;
  if (ref_parts)
  {
    KEY_PART_INFO *key_part=
      table->key_info[table->reginfo.join_tab->ref.key].key_part;

    for (uint part=0 ; part < ref_parts ; part++,key_part++)
      if (field->eq(key_part->field) &&
7403
	  !(key_part->key_part_flag & (HA_PART_KEY_SEG | HA_NULL_PART)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7404 7405 7406 7407 7408 7409 7410
	return table->reginfo.join_tab->ref.items[part];
  }
  return (Item*) 0;
}


/*****************************************************************************
7411
  Test if one can use the key to resolve ORDER BY
7412 7413 7414 7415 7416 7417 7418 7419 7420 7421 7422 7423 7424 7425 7426 7427 7428

  SYNOPSIS
    test_if_order_by_key()
    order		Sort order
    table		Table to sort
    idx			Index to check
    used_key_parts	Return value for used key parts.


  NOTES
    used_key_parts is set to correct key parts used if return value != 0
    (On other cases, used_key_part may be changed)

  RETURN
    1   key is ok.
    0   Key can't be used
    -1  Reverse key can be used
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7429 7430
*****************************************************************************/

7431 7432
static int test_if_order_by_key(ORDER *order, TABLE *table, uint idx,
				uint *used_key_parts)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7433 7434 7435 7436 7437 7438
{
  KEY_PART_INFO *key_part,*key_part_end;
  key_part=table->key_info[idx].key_part;
  key_part_end=key_part+table->key_info[idx].key_parts;
  key_part_map const_key_parts=table->const_key_parts[idx];
  int reverse=0;
7439
  DBUG_ENTER("test_if_order_by_key");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7440 7441 7442 7443 7444 7445 7446 7447 7448 7449

  for (; order ; order=order->next, const_key_parts>>=1)
  {
    Field *field=((Item_field*) (*order->item))->field;
    int flag;

    /*
      Skip key parts that are constants in the WHERE clause.
      These are already skipped in the ORDER BY by const_expression_in_where()
    */
7450 7451 7452
    for (; const_key_parts & 1 ; const_key_parts>>= 1)
      key_part++; 

bk@work.mysql.com's avatar
bk@work.mysql.com committed
7453
    if (key_part == key_part_end || key_part->field != field)
7454
      DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7455 7456

    /* set flag to 1 if we can use read-next on key, else to -1 */
7457 7458
    flag= ((order->asc == !(key_part->key_part_flag & HA_REVERSE_SORT)) ?
           1 : -1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7459
    if (reverse && flag != reverse)
7460
      DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7461 7462 7463
    reverse=flag;				// Remember if reverse
    key_part++;
  }
7464 7465 7466 7467
  *used_key_parts= (uint) (key_part - table->key_info[idx].key_part);
  if (reverse == -1 && !(table->file->index_flags(idx, *used_key_parts-1, 1) &
                         HA_READ_PREV))
    reverse= 0;                                 // Index can't be used
7468
  DBUG_RETURN(reverse);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7469 7470
}

7471

serg@serg.mylan's avatar
serg@serg.mylan committed
7472
static uint find_shortest_key(TABLE *table, const key_map *usable_keys)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7473 7474 7475
{
  uint min_length= (uint) ~0;
  uint best= MAX_KEY;
serg@serg.mylan's avatar
serg@serg.mylan committed
7476
  if (!usable_keys->is_clear_all())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7477
  {
serg@serg.mylan's avatar
serg@serg.mylan committed
7478
    for (uint nr=0; nr < table->keys ; nr++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7479
    {
serg@serg.mylan's avatar
serg@serg.mylan committed
7480
      if (usable_keys->is_set(nr))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7481
      {
7482 7483 7484 7485 7486
        if (table->key_info[nr].key_length < min_length)
        {
          min_length=table->key_info[nr].key_length;
          best=nr;
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7487 7488 7489 7490 7491 7492
      }
    }
  }
  return best;
}

7493
/*
7494 7495
  Test if a second key is the subkey of the first one.

7496 7497
  SYNOPSIS
    is_subkey()
7498 7499 7500 7501
    key_part		First key parts
    ref_key_part	Second key parts
    ref_key_part_end	Last+1 part of the second key

7502 7503
  NOTE
    Second key MUST be shorter than the first one.
7504

7505
  RETURN
7506 7507
    1	is a subkey
    0	no sub key
7508 7509 7510 7511 7512 7513 7514 7515 7516 7517 7518 7519 7520
*/

inline bool 
is_subkey(KEY_PART_INFO *key_part, KEY_PART_INFO *ref_key_part,
	  KEY_PART_INFO *ref_key_part_end)
{
  for (; ref_key_part < ref_key_part_end; key_part++, ref_key_part++)
    if (!key_part->field->eq(ref_key_part->field))
      return 0;
  return 1;
}

/*
7521 7522
  Test if we can use one of the 'usable_keys' instead of 'ref' key for sorting

7523 7524
  SYNOPSIS
    test_if_subkey()
7525 7526 7527
    ref			Number of key, used for WHERE clause
    usable_keys		Keys for testing

7528
  RETURN
7529 7530
    MAX_KEY			If we can't use other key
    the number of found key	Otherwise
7531 7532 7533
*/

static uint
7534
test_if_subkey(ORDER *order, TABLE *table, uint ref, uint ref_key_parts,
7535
	       const key_map *usable_keys)
7536 7537 7538 7539 7540 7541 7542
{
  uint nr;
  uint min_length= (uint) ~0;
  uint best= MAX_KEY;
  uint not_used;
  KEY_PART_INFO *ref_key_part= table->key_info[ref].key_part;
  KEY_PART_INFO *ref_key_part_end= ref_key_part + ref_key_parts;
7543

serg@serg.mylan's avatar
serg@serg.mylan committed
7544
  for (nr= 0 ; nr < table->keys ; nr++)
7545
  {
7546
    if (usable_keys->is_set(nr) &&
7547 7548 7549 7550 7551 7552 7553 7554 7555 7556 7557 7558
	table->key_info[nr].key_length < min_length &&
	table->key_info[nr].key_parts >= ref_key_parts &&
	is_subkey(table->key_info[nr].key_part, ref_key_part,
		  ref_key_part_end) &&
	test_if_order_by_key(order, table, nr, &not_used))
    {
      min_length= table->key_info[nr].key_length;
      best= nr;
    }
  }
  return best;
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7559

7560 7561 7562 7563 7564 7565 7566 7567 7568 7569 7570 7571 7572 7573 7574 7575 7576 7577 7578 7579 7580 7581 7582 7583 7584 7585 7586 7587 7588 7589 7590 7591 7592 7593 7594 7595 7596 7597 7598 7599 7600 7601 7602 7603 7604 7605 7606 7607 7608 7609 7610 7611 7612 7613 7614 7615 7616 7617 7618 7619 7620 7621 7622 7623 7624 7625 7626 7627 7628 7629 7630 7631 7632 7633 7634 7635 7636 7637 7638 7639 7640 7641 7642 7643 7644 7645 7646 7647 7648 7649 7650 7651 7652 7653 7654 7655 7656 7657 7658 7659 7660 7661 7662 7663 7664 7665 7666 7667 7668 7669 7670 7671 7672 7673 7674 7675 7676 7677 7678 7679 7680 7681 7682 7683 7684 7685 7686 7687 7688 7689 7690 7691 7692 7693

/*
  Check if GROUP BY/DISTINCT can be optimized away because the set is 
  already known to be distinct.
  
  SYNOPSIS
    list_contains_unique_index ()
    table                The table to operate on.
    find_func            function to iterate over the list and search
                         for a field
  
  DESCRIPTION
    Used in removing the GROUP BY/DISTINCT of the following types of
    statements:
      SELECT [DISTINCT] <unique_key_cols>... FROM <single_table_ref>
        [GROUP BY <unique_key_cols>,...]

    If (a,b,c is distinct)
      then <any combination of a,b,c>,{whatever} is also distinct

    This function checks if all the key parts of any of the unique keys
    of the table are referenced by a list : either the select list 
    through find_field_in_item_list or GROUP BY list through
    find_field_in_order_list.
    If the above holds then we can safely remove the GROUP BY/DISTINCT,
    as no result set can be more distinct than an unique key.
  
  RETURN VALUE
    1                    found
    0                    not found.
*/

static bool
list_contains_unique_index(TABLE *table,
                          bool (*find_func) (Field *, void *), void *data)
{
  for (uint keynr= 0; keynr < table->keys; keynr++)
  {
    if (keynr == table->primary_key ||
         (table->key_info[keynr].flags & HA_NOSAME))
    {
      KEY *keyinfo= table->key_info + keynr;
      KEY_PART_INFO *key_part, *key_part_end;

      for (key_part=keyinfo->key_part,
           key_part_end=key_part+ keyinfo->key_parts;
           key_part < key_part_end;
           key_part++)
      {
        if (!find_func(key_part->field, data))
          break;
      }
      if (key_part == key_part_end)
        return 1;
    }
  }
  return 0;
}


/*
  Helper function for list_contains_unique_index.
  Find a field reference in a list of ORDER structures.
  
  SYNOPSIS
    find_field_in_order_list ()
    field                The field to search for.
    data                 ORDER *.The list to search in
  
  DESCRIPTION
    Finds a direct reference of the Field in the list.
  
  RETURN VALUE
    1                    found
    0                    not found.
*/

static bool
find_field_in_order_list (Field *field, void *data)
{
  ORDER *group= (ORDER *) data;
  bool part_found= 0;
  for (ORDER *tmp_group= group; tmp_group; tmp_group=tmp_group->next)
  {
    Item *item= (*tmp_group->item)->real_item();
    if (item->type() == Item::FIELD_ITEM &&
        ((Item_field*) item)->field->eq(field))
    {
      part_found= 1;
      break;
    }
  }
  return part_found;
}


/*
  Helper function for list_contains_unique_index.
  Find a field reference in a dynamic list of Items.
  
  SYNOPSIS
    find_field_in_item_list ()
    field in             The field to search for.
    data  in             List<Item> *.The list to search in
  
  DESCRIPTION
    Finds a direct reference of the Field in the list.
  
  RETURN VALUE
    1                    found
    0                    not found.
*/

static bool
find_field_in_item_list (Field *field, void *data)
{
  List<Item> *fields= (List<Item> *) data;
  bool part_found= 0;
  List_iterator<Item> li(*fields);
  Item *item;

  while ((item= li++))
  {
    if (item->type() == Item::FIELD_ITEM &&
        ((Item_field*) item)->field->eq(field))
    {
      part_found= 1;
      break;
    }
  }
  return part_found;
}


7694 7695 7696 7697 7698 7699 7700 7701 7702 7703
/*
  Test if we can skip the ORDER BY by using an index.

  If we can use an index, the JOIN_TAB / tab->select struct
  is changed to use the index.

  Return:
     0 We have to use filesort to do the sorting
     1 We can use an index.
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7704 7705

static bool
7706 7707
test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
			bool no_changes)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7708 7709
{
  int ref_key;
7710
  uint ref_key_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7711 7712 7713 7714
  TABLE *table=tab->table;
  SQL_SELECT *select=tab->select;
  key_map usable_keys;
  DBUG_ENTER("test_if_skip_sort_order");
7715
  LINT_INIT(ref_key_parts);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7716

7717 7718 7719 7720 7721 7722
  /*
    Check which keys can be used to resolve ORDER BY.
    We must not try to use disabled keys.
  */
  usable_keys= table->keys_in_use;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
7723 7724 7725 7726
  for (ORDER *tmp_order=order; tmp_order ; tmp_order=tmp_order->next)
  {
    if ((*tmp_order->item)->type() != Item::FIELD_ITEM)
    {
7727
      usable_keys.clear_all();
7728
      DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7729
    }
7730 7731
    usable_keys.intersect(((Item_field*) (*tmp_order->item))->
			  field->part_of_sortkey);
serg@serg.mylan's avatar
serg@serg.mylan committed
7732
    if (usable_keys.is_clear_all())
7733
      DBUG_RETURN(0);					// No usable keys
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7734 7735 7736
  }

  ref_key= -1;
7737
  /* Test if constant range in WHERE */
7738
  if (tab->ref.key >= 0 && tab->ref.key_parts)
7739 7740 7741
  {
    ref_key=	   tab->ref.key;
    ref_key_parts= tab->ref.key_parts;
7742
    if (tab->type == JT_REF_OR_NULL || tab->type == JT_FT)
7743
      DBUG_RETURN(0);
7744
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7745
  else if (select && select->quick)		// Range found by opt_range
7746 7747 7748 7749
  {
    ref_key=	   select->quick->index;
    ref_key_parts= select->quick->used_key_parts;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7750 7751 7752

  if (ref_key >= 0)
  {
7753 7754 7755
    /*
      We come here when there is a REF key.
    */
7756
    int order_direction;
7757
    uint used_key_parts;
7758
    if (!usable_keys.is_set(ref_key))
7759 7760 7761 7762
    {
      /*
	We come here when ref_key is not among usable_keys
      */
7763 7764 7765 7766 7767
      uint new_ref_key;
      /*
	If using index only read, only consider other possible index only
	keys
      */
7768
      if (table->used_keys.is_set(ref_key))
7769
	usable_keys.intersect(table->used_keys);
7770
      if ((new_ref_key= test_if_subkey(order, table, ref_key, ref_key_parts,
7771
				       &usable_keys)) < MAX_KEY)
7772
      {
7773
	/* Found key that can be used to retrieve data in sorted order */
7774 7775
	if (tab->ref.key >= 0)
	{
7776 7777 7778
          /*
            We'll use ref access method on key new_ref_key. In general case 
            the index search tuple for new_ref_key will be different (e.g.
sergefp@mysql.com's avatar
sergefp@mysql.com committed
7779 7780 7781
            when one index is defined as (part1, part2, ...) and another as
            (part1, part2(N), ...) and the WHERE clause contains 
            "part1 = const1 AND part2=const2". 
7782 7783 7784 7785 7786 7787 7788 7789
            So we build tab->ref from scratch here.
          */
          KEYUSE *keyuse= tab->keyuse;
          while (keyuse->key != new_ref_key && keyuse->table == tab->table)
            keyuse++;
          if (create_ref_for_key(tab->join, tab, keyuse, 
                                 tab->join->const_table_map))
            DBUG_RETURN(0);
7790 7791 7792
	}
	else
	{
timour@mysql.com's avatar
timour@mysql.com committed
7793 7794 7795 7796 7797 7798 7799 7800 7801
          /*
            The range optimizer constructed QUICK_RANGE for ref_key, and
            we want to use instead new_ref_key as the index. We can't
            just change the index of the quick select, because this may
            result in an incosistent QUICK_SELECT object. Below we
            create a new QUICK_SELECT from scratch so that all its
            parameres are set correctly by the range optimizer.
           */
          key_map new_ref_key_map;
7802 7803
          new_ref_key_map.clear_all();  // Force the creation of quick select
          new_ref_key_map.set_bit(new_ref_key); // only for new_ref_key.
timour@mysql.com's avatar
timour@mysql.com committed
7804 7805

          if (select->test_quick_select(tab->join->thd, new_ref_key_map, 0,
7806 7807 7808 7809 7810
                                        (tab->join->select_options &
                                         OPTION_FOUND_ROWS) ?
                                        HA_POS_ERROR :
                                        tab->join->unit->select_limit_cnt,0) <=
              0)
timour@mysql.com's avatar
timour@mysql.com committed
7811
            DBUG_RETURN(0);
7812
	}
timour@mysql.com's avatar
timour@mysql.com committed
7813
        ref_key= new_ref_key;
7814
      }
7815
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7816
    /* Check if we get the rows in requested sorted order by using the key */
7817
    if (usable_keys.is_set(ref_key) &&
7818 7819
	(order_direction = test_if_order_by_key(order,table,ref_key,
						&used_key_parts)))
7820
    {
7821
      if (order_direction == -1)		// If ORDER BY ... DESC
7822
      {
7823 7824
	if (select && select->quick)
	{
7825 7826 7827 7828 7829
	  /*
	    Don't reverse the sort order, if it's already done.
	    (In some cases test_if_order_by_key() can be called multiple times
	  */
	  if (!select->quick->reverse_sorted())
7830
	  {
7831 7832 7833 7834 7835 7836 7837 7838 7839
	    // ORDER BY range_key DESC
	    QUICK_SELECT_DESC *tmp=new QUICK_SELECT_DESC(select->quick,
							 used_key_parts);
	    if (!tmp || tmp->error)
	    {
	      delete tmp;
	      DBUG_RETURN(0);		// Reverse sort not supported
	    }
	    select->quick=tmp;
7840 7841 7842 7843 7844 7845 7846
	  }
	  DBUG_RETURN(1);
	}
	if (tab->ref.key_parts < used_key_parts)
	{
	  /*
	    SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
7847 7848 7849

	    Use a traversal function that starts by reading the last row
	    with key part (A) and then traverse the index backwards.
7850
	  */
7851 7852 7853
	  tab->read_first_record=       join_read_last_key;
	  tab->read_record.read_record= join_read_prev_same;
	  /* fall through */
7854
	}
7855
      }
7856 7857
      else if (select && select->quick)
	  select->quick->sorted= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7858
      DBUG_RETURN(1);			/* No need to sort */
7859
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7860 7861 7862 7863 7864 7865
  }
  else
  {
    /* check if we can use a key to resolve the group */
    /* Tables using JT_NEXT are handled here */
    uint nr;
monty@mysql.com's avatar
monty@mysql.com committed
7866
    key_map keys;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7867 7868 7869 7870 7871 7872 7873

    /*
      If not used with LIMIT, only use keys if the whole query can be
      resolved with a key;  This is because filesort() is usually faster than
      retrieving all rows through an index.
    */
    if (select_limit >= table->file->records)
monty@mysql.com's avatar
monty@mysql.com committed
7874 7875 7876
    {
      keys= *table->file->keys_to_use_for_scanning();
      keys.merge(table->used_keys);
7877

monty@mysql.com's avatar
monty@mysql.com committed
7878
      /*
monty@mysql.com's avatar
monty@mysql.com committed
7879
	We are adding here also the index specified in FORCE INDEX clause, 
monty@mysql.com's avatar
monty@mysql.com committed
7880
	if any.
monty@mysql.com's avatar
monty@mysql.com committed
7881
        This is to allow users to use index in ORDER BY.
monty@mysql.com's avatar
monty@mysql.com committed
7882 7883 7884 7885
      */
      if (table->force_index) 
	keys.merge(table->keys_in_use_for_query);
      keys.intersect(usable_keys);
7886 7887
    }
    else
7888
      keys= usable_keys;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7889

serg@serg.mylan's avatar
serg@serg.mylan committed
7890
    for (nr=0; nr < table->keys ; nr++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7891
    {
7892
      uint not_used;
7893
      if (keys.is_set(nr))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7894 7895
      {
	int flag;
monty@mysql.com's avatar
monty@mysql.com committed
7896
	if ((flag= test_if_order_by_key(order, table, nr, &not_used)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7897
	{
7898 7899 7900
	  if (!no_changes)
	  {
	    tab->index=nr;
7901 7902
	    tab->read_first_record=  (flag > 0 ? join_read_first:
				      join_read_last);
7903
	    tab->type=JT_NEXT;	// Read with index_first(), index_next()
7904
	    if (table->used_keys.is_set(nr))
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
7905 7906 7907 7908
	    {
	      table->key_read=1;
	      table->file->extra(HA_EXTRA_KEYREAD);
	    }
7909
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7910 7911 7912 7913 7914 7915 7916 7917
	  DBUG_RETURN(1);
	}
      }
    }
  }
  DBUG_RETURN(0);				// Can't use index.
}

7918

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7919
/*
7920
  If not selecting by given key, create an index how records should be read
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7921 7922 7923 7924 7925 7926 7927 7928

  SYNOPSIS
   create_sort_index()
     thd		Thread handler
     tab		Table to sort (in join structure)
     order		How table should be sorted
     filesort_limit	Max number of rows that needs to be sorted
     select_limit	Max number of rows in final output
7929
		        Used to decide if we should use index or not
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
7930 7931 7932 7933 7934 7935 7936 7937 7938 7939 7940 7941 7942 7943 7944


  IMPLEMENTATION
   - If there is an index that can be used, 'tab' is modified to use
     this index.
   - If no index, create with filesort() an index file that can be used to
     retrieve rows in order (should be done with 'read_record').
     The sorted data is stored in tab->table and will be freed when calling
     free_io_cache(tab->table).

  RETURN VALUES
    0		ok
    -1		Some fatal error
    1		No records
*/
7945

bk@work.mysql.com's avatar
bk@work.mysql.com committed
7946
static int
7947
create_sort_index(THD *thd, JOIN *join, ORDER *order,
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
7948
		  ha_rows filesort_limit, ha_rows select_limit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7949 7950 7951
{
  SORT_FIELD *sortorder;
  uint length;
7952
  ha_rows examined_rows;
7953 7954 7955
  TABLE *table;
  SQL_SELECT *select;
  JOIN_TAB *tab;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7956 7957
  DBUG_ENTER("create_sort_index");

7958 7959 7960 7961 7962 7963
  if (join->tables == join->const_tables)
    DBUG_RETURN(0);				// One row, no need to sort
  tab=    join->join_tab + join->const_tables;
  table=  tab->table;
  select= tab->select;

7964
  if (test_if_skip_sort_order(tab,order,select_limit,0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7965 7966 7967 7968
    DBUG_RETURN(0);
  if (!(sortorder=make_unireg_sortorder(order,&length)))
    goto err;				/* purecov: inspected */
  /* It's not fatal if the following alloc fails */
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
7969 7970
  table->sort.io_cache=(IO_CACHE*) my_malloc(sizeof(IO_CACHE),
                                             MYF(MY_WME | MY_ZEROFILL));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7971 7972 7973 7974 7975 7976 7977 7978 7979 7980 7981 7982 7983 7984 7985 7986 7987 7988 7989 7990 7991
  table->status=0;				// May be wrong if quick_select

  // If table has a range, move it to select
  if (select && !select->quick && tab->ref.key >= 0)
  {
    if (tab->quick)
    {
      select->quick=tab->quick;
      tab->quick=0;
      /* We can only use 'Only index' if quick key is same as ref_key */
      if (table->key_read && (uint) tab->ref.key != select->quick->index)
      {
	table->key_read=0;
	table->file->extra(HA_EXTRA_NO_KEYREAD);
      }
    }
    else
    {
      /*
	We have a ref on a const;  Change this to a range that filesort
	can use.
7992 7993
	For impossible ranges (like when doing a lookup on NULL on a NOT NULL
	field, quick will contain an empty record set.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7994
      */
7995 7996 7997
      if (!(select->quick= (tab->type == JT_FT ?
			    new FT_SELECT(thd, table, tab->ref.key) :
			    get_quick_select_for_ref(thd, table, &tab->ref))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7998 7999 8000
	goto err;
    }
  }
8001 8002
  if (table->tmp_table)
    table->file->info(HA_STATUS_VARIABLE);	// Get record count
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
8003 8004
  table->sort.found_records=filesort(thd, table,sortorder, length,
                                     select, filesort_limit, &examined_rows);
monty@mysql.com's avatar
merge  
monty@mysql.com committed
8005
  tab->records= table->sort.found_records;	// For SQL_CALC_ROWS
8006 8007 8008 8009 8010
  if (select)
  {
    select->cleanup();				// filesort did select
    tab->select= 0;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8011 8012 8013
  tab->select_cond=0;
  tab->type=JT_ALL;				// Read with normal read_record
  tab->read_first_record= join_init_read_record;
8014
  tab->join->examined_rows+=examined_rows;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8015 8016 8017 8018 8019
  if (table->key_read)				// Restore if we used indexes
  {
    table->key_read=0;
    table->file->extra(HA_EXTRA_NO_KEYREAD);
  }
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
8020
  DBUG_RETURN(table->sort.found_records == HA_POS_ERROR);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8021 8022 8023 8024
err:
  DBUG_RETURN(-1);
}

8025
/*
8026
  Add the HAVING criteria to table->select
8027 8028
*/

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
8029
#ifdef NOT_YET
8030 8031 8032 8033 8034 8035
static bool fix_having(JOIN *join, Item **having)
{
  (*having)->update_used_tables();	// Some tables may have been const
  JOIN_TAB *table=&join->join_tab[join->const_tables];
  table_map used_tables= join->const_table_map | table->table->map;

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
8036
  DBUG_EXECUTE("where",print_where(*having,"having"););
8037 8038 8039 8040 8041 8042 8043 8044 8045
  Item* sort_table_cond=make_cond_for_table(*having,used_tables,used_tables);
  if (sort_table_cond)
  {
    if (!table->select)
      if (!(table->select=new SQL_SELECT))
	return 1;
    if (!table->select->cond)
      table->select->cond=sort_table_cond;
    else					// This should never happen
8046 8047
      if (!(table->select->cond= new Item_cond_and(table->select->cond,
						   sort_table_cond)) ||
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8048
	  table->select->cond->fix_fields(join->thd, join->tables_list,
8049
					  &table->select->cond))
8050 8051
	return 1;
    table->select_cond=table->select->cond;
8052
    table->select_cond->top_level_item();
8053 8054 8055 8056 8057 8058 8059
    DBUG_EXECUTE("where",print_where(table->select_cond,
				     "select and having"););
    *having=make_cond_for_table(*having,~ (table_map) 0,~used_tables);
    DBUG_EXECUTE("where",print_where(*having,"having after make_cond"););
  }
  return 0;
}
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
8060
#endif
8061 8062


bk@work.mysql.com's avatar
bk@work.mysql.com committed
8063
/*****************************************************************************
8064 8065 8066 8067 8068
  Remove duplicates from tmp table
  This should be recoded to add a unique index to the table and remove
  duplicates
  Table is a locked single thread table
  fields is the number of fields to check (from the end)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8069 8070 8071 8072 8073 8074 8075 8076 8077 8078 8079 8080 8081 8082 8083 8084 8085 8086 8087 8088 8089 8090 8091 8092 8093 8094 8095 8096 8097 8098 8099 8100 8101 8102
*****************************************************************************/

static bool compare_record(TABLE *table, Field **ptr)
{
  for (; *ptr ; ptr++)
  {
    if ((*ptr)->cmp_offset(table->rec_buff_length))
      return 1;
  }
  return 0;
}

static bool copy_blobs(Field **ptr)
{
  for (; *ptr ; ptr++)
  {
    if ((*ptr)->flags & BLOB_FLAG)
      if (((Field_blob *) (*ptr))->copy())
	return 1;				// Error
  }
  return 0;
}

static void free_blobs(Field **ptr)
{
  for (; *ptr ; ptr++)
  {
    if ((*ptr)->flags & BLOB_FLAG)
      ((Field_blob *) (*ptr))->free();
  }
}


static int
8103
remove_duplicates(JOIN *join, TABLE *entry,List<Item> &fields, Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8104 8105 8106 8107
{
  int error;
  ulong reclength,offset;
  uint field_count;
8108
  THD *thd= join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8109 8110 8111 8112 8113 8114 8115 8116 8117
  DBUG_ENTER("remove_duplicates");

  entry->reginfo.lock_type=TL_WRITE;

  /* Calculate how many saved fields there is in list */
  field_count=0;
  List_iterator<Item> it(fields);
  Item *item;
  while ((item=it++))
8118
  {
8119
    if (item->get_tmp_table_field() && ! item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8120
      field_count++;
8121
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8122

igor@olga.mysql.com's avatar
igor@olga.mysql.com committed
8123
  if (!field_count && !(join->select_options & OPTION_FOUND_ROWS) && !having) 
8124
  {                    // only const items with no OPTION_FOUND_ROWS
8125
    join->unit->select_limit_cnt= 1;		// Only send first row
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8126 8127 8128
    DBUG_RETURN(0);
  }
  Field **first_field=entry->field+entry->fields - field_count;
8129 8130
  offset= field_count ? 
          entry->field[entry->fields - field_count]->offset() : 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8131 8132 8133 8134 8135 8136
  reclength=entry->reclength-offset;

  free_io_cache(entry);				// Safety
  entry->file->info(HA_STATUS_VARIABLE);
  if (entry->db_type == DB_TYPE_HEAP ||
      (!entry->blob_fields &&
8137
       ((ALIGN_SIZE(reclength) + HASH_OVERHEAD) * entry->file->records <
8138
	thd->variables.sortbuff_size)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8139 8140
    error=remove_dup_with_hash_index(join->thd, entry,
				     field_count, first_field,
8141
				     reclength, having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8142
  else
8143 8144
    error=remove_dup_with_compare(join->thd, entry, first_field, offset,
				  having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8145 8146 8147 8148 8149 8150 8151

  free_blobs(first_field);
  DBUG_RETURN(error);
}


static int remove_dup_with_compare(THD *thd, TABLE *table, Field **first_field,
8152
				   ulong offset, Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8153 8154 8155
{
  handler *file=table->file;
  char *org_record,*new_record;
monty@donna.mysql.fi's avatar
monty@donna.mysql.fi committed
8156
  byte *record;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8157 8158 8159 8160
  int error;
  ulong reclength=table->reclength-offset;
  DBUG_ENTER("remove_dup_with_compare");

8161
  org_record=(char*) (record=table->record[0])+offset;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8162 8163
  new_record=(char*) table->record[1]+offset;

8164
  file->ha_rnd_init(1);
8165
  error=file->rnd_next(record);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8166 8167 8168 8169 8170 8171 8172 8173 8174 8175 8176 8177 8178 8179 8180 8181
  for (;;)
  {
    if (thd->killed)
    {
      my_error(ER_SERVER_SHUTDOWN,MYF(0));
      error=0;
      goto err;
    }
    if (error)
    {
      if (error == HA_ERR_RECORD_DELETED)
	continue;
      if (error == HA_ERR_END_OF_FILE)
	break;
      goto err;
    }
8182 8183 8184 8185
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
8186
      error=file->rnd_next(record);
8187 8188
      continue;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8189 8190
    if (copy_blobs(first_field))
    {
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
8191
      my_error(ER_OUTOFMEMORY,MYF(0));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8192 8193 8194 8195 8196 8197 8198 8199 8200
      error=0;
      goto err;
    }
    memcpy(new_record,org_record,reclength);

    /* Read through rest of file and mark duplicated rows deleted */
    bool found=0;
    for (;;)
    {
8201
      if ((error=file->rnd_next(record)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8202 8203 8204 8205 8206 8207 8208 8209 8210
      {
	if (error == HA_ERR_RECORD_DELETED)
	  continue;
	if (error == HA_ERR_END_OF_FILE)
	  break;
	goto err;
      }
      if (compare_record(table, first_field) == 0)
      {
8211
	if ((error=file->delete_row(record)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8212 8213 8214 8215 8216
	  goto err;
      }
      else if (!found)
      {
	found=1;
8217
	file->position(record);	// Remember position
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8218 8219 8220 8221 8222
      }
    }
    if (!found)
      break;					// End of file
    /* Restart search on next row */
8223
    error=file->restart_rnd_next(record,file->ref);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8224 8225 8226 8227 8228 8229 8230 8231 8232 8233 8234 8235 8236 8237 8238 8239 8240 8241 8242 8243
  }

  file->extra(HA_EXTRA_NO_CACHE);
  DBUG_RETURN(0);
err:
  file->extra(HA_EXTRA_NO_CACHE);
  if (error)
    file->print_error(error,MYF(0));
  DBUG_RETURN(1);
}


/*
  Generate a hash index for each row to quickly find duplicate rows
  Note that this will not work on tables with blobs!
*/

static int remove_dup_with_hash_index(THD *thd, TABLE *table,
				      uint field_count,
				      Field **first_field,
8244 8245
				      ulong key_length,
				      Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8246 8247 8248
{
  byte *key_buffer, *key_pos, *record=table->record[0];
  int error;
8249 8250
  handler *file= table->file;
  ulong extra_length= ALIGN_SIZE(key_length)-key_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8251 8252 8253 8254 8255 8256 8257 8258 8259 8260 8261 8262
  uint *field_lengths,*field_length;
  HASH hash;
  DBUG_ENTER("remove_dup_with_hash_index");

  if (!my_multi_malloc(MYF(MY_WME),
		       &key_buffer,
		       (uint) ((key_length + extra_length) *
			       (long) file->records),
		       &field_lengths,
		       (uint) (field_count*sizeof(*field_lengths)),
		       NullS))
    DBUG_RETURN(1);
8263

8264 8265 8266 8267 8268 8269 8270 8271 8272 8273 8274 8275 8276 8277 8278 8279
  {
    Field **ptr;
    ulong total_length= 0;
    for (ptr= first_field, field_length=field_lengths ; *ptr ; ptr++)
    {
      uint length= (*ptr)->pack_length();
      (*field_length++)= length;
      total_length+= length;
    }
    DBUG_PRINT("info",("field_count: %u  key_length: %lu  total_length: %lu",
                       field_count, key_length, total_length));
    DBUG_ASSERT(total_length <= key_length);
    key_length= total_length;
    extra_length= ALIGN_SIZE(key_length)-key_length;
  }

bar@bar.mysql.r18.ru's avatar
bar@bar.mysql.r18.ru committed
8280
  if (hash_init(&hash, &my_charset_bin, (uint) file->records, 0, 
8281
		key_length, (hash_get_key) 0, 0, 0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8282 8283 8284 8285 8286
  {
    my_free((char*) key_buffer,MYF(0));
    DBUG_RETURN(1);
  }

8287
  file->ha_rnd_init(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8288 8289 8290
  key_pos=key_buffer;
  for (;;)
  {
8291
    byte *org_key_pos;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8292 8293 8294 8295 8296 8297 8298 8299 8300 8301 8302 8303 8304 8305
    if (thd->killed)
    {
      my_error(ER_SERVER_SHUTDOWN,MYF(0));
      error=0;
      goto err;
    }
    if ((error=file->rnd_next(record)))
    {
      if (error == HA_ERR_RECORD_DELETED)
	continue;
      if (error == HA_ERR_END_OF_FILE)
	break;
      goto err;
    }
8306 8307 8308 8309 8310
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
      continue;
8311
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8312 8313

    /* copy fields to key buffer */
8314
    org_key_pos= key_pos;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8315 8316 8317 8318 8319 8320 8321
    field_length=field_lengths;
    for (Field **ptr= first_field ; *ptr ; ptr++)
    {
      (*ptr)->sort_string((char*) key_pos,*field_length);
      key_pos+= *field_length++;
    }
    /* Check if it exists before */
8322
    if (hash_search(&hash, org_key_pos, key_length))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8323 8324 8325 8326 8327
    {
      /* Duplicated found ; Remove the row */
      if ((error=file->delete_row(record)))
	goto err;
    }
8328
    else
8329
      (void) my_hash_insert(&hash, org_key_pos);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8330 8331 8332 8333 8334
    key_pos+=extra_length;
  }
  my_free((char*) key_buffer,MYF(0));
  hash_free(&hash);
  file->extra(HA_EXTRA_NO_CACHE);
8335
  (void) file->ha_rnd_end();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8336 8337 8338 8339 8340 8341
  DBUG_RETURN(0);

err:
  my_free((char*) key_buffer,MYF(0));
  hash_free(&hash);
  file->extra(HA_EXTRA_NO_CACHE);
8342
  (void) file->ha_rnd_end();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8343 8344 8345 8346 8347 8348
  if (error)
    file->print_error(error,MYF(0));
  DBUG_RETURN(1);
}


8349
SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8350 8351 8352 8353 8354 8355 8356 8357 8358 8359 8360 8361 8362 8363 8364 8365 8366 8367 8368
{
  uint count;
  SORT_FIELD *sort,*pos;
  DBUG_ENTER("make_unireg_sortorder");

  count=0;
  for (ORDER *tmp = order; tmp; tmp=tmp->next)
    count++;
  pos=sort=(SORT_FIELD*) sql_alloc(sizeof(SORT_FIELD)*(count+1));
  if (!pos)
    return 0;

  for (;order;order=order->next,pos++)
  {
    pos->field=0; pos->item=0;
    if (order->item[0]->type() == Item::FIELD_ITEM)
      pos->field= ((Item_field*) (*order->item))->field;
    else if (order->item[0]->type() == Item::SUM_FUNC_ITEM &&
	     !order->item[0]->const_item())
8369
      pos->field= ((Item_sum*) order->item[0])->get_tmp_table_field();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8370 8371 8372 8373 8374 8375 8376 8377 8378 8379 8380 8381 8382 8383
    else if (order->item[0]->type() == Item::COPY_STR_ITEM)
    {						// Blob patch
      pos->item= ((Item_copy_string*) (*order->item))->item;
    }
    else
      pos->item= *order->item;
    pos->reverse=! order->asc;
  }
  *length=count;
  DBUG_RETURN(sort);
}


/*****************************************************************************
8384 8385 8386 8387
  Fill join cache with packed records
  Records are stored in tab->cache.buffer and last record in
  last record is stored with pointers to blobs to support very big
  records
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8388 8389 8390 8391 8392 8393 8394 8395 8396
******************************************************************************/

static int
join_init_cache(THD *thd,JOIN_TAB *tables,uint table_count)
{
  reg1 uint i;
  uint length,blobs,size;
  CACHE_FIELD *copy,**blob_ptr;
  JOIN_CACHE  *cache;
8397
  JOIN_TAB *join_tab;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8398 8399 8400 8401 8402
  DBUG_ENTER("join_init_cache");

  cache= &tables[table_count].cache;
  cache->fields=blobs=0;

8403 8404
  join_tab=tables;
  for (i=0 ; i < table_count ; i++,join_tab++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8405
  {
8406 8407 8408 8409
    if (!join_tab->used_fieldlength)		/* Not calced yet */
      calc_used_field_length(thd, join_tab);
    cache->fields+=join_tab->used_fields;
    blobs+=join_tab->used_blobs;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8410 8411 8412 8413 8414 8415 8416 8417 8418 8419 8420 8421 8422 8423 8424 8425 8426 8427 8428 8429 8430 8431 8432 8433 8434 8435 8436 8437 8438 8439 8440 8441 8442 8443 8444 8445 8446 8447 8448
  }
  if (!(cache->field=(CACHE_FIELD*)
	sql_alloc(sizeof(CACHE_FIELD)*(cache->fields+table_count*2)+(blobs+1)*
		  sizeof(CACHE_FIELD*))))
  {
    my_free((gptr) cache->buff,MYF(0));		/* purecov: inspected */
    cache->buff=0;				/* purecov: inspected */
    DBUG_RETURN(1);				/* purecov: inspected */
  }
  copy=cache->field;
  blob_ptr=cache->blob_ptr=(CACHE_FIELD**)
    (cache->field+cache->fields+table_count*2);

  length=0;
  for (i=0 ; i < table_count ; i++)
  {
    uint null_fields=0,used_fields;

    Field **f_ptr,*field;
    for (f_ptr=tables[i].table->field,used_fields=tables[i].used_fields ;
	 used_fields ;
	 f_ptr++)
    {
      field= *f_ptr;
      if (field->query_id == thd->query_id)
      {
	used_fields--;
	length+=field->fill_cache_field(copy);
	if (copy->blob_field)
	  (*blob_ptr++)=copy;
	if (field->maybe_null())
	  null_fields++;
	copy++;
      }
    }
    /* Copy null bits from table */
    if (null_fields && tables[i].table->null_fields)
    {						/* must copy null bits */
      copy->str=(char*) tables[i].table->null_flags;
8449
      copy->length=tables[i].table->null_bytes;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8450 8451 8452 8453 8454 8455 8456 8457 8458 8459 8460 8461 8462 8463 8464 8465 8466 8467 8468 8469 8470 8471
      copy->strip=0;
      copy->blob_field=0;
      length+=copy->length;
      copy++;
      cache->fields++;
    }
    /* If outer join table, copy null_row flag */
    if (tables[i].table->maybe_null)
    {
      copy->str= (char*) &tables[i].table->null_row;
      copy->length=sizeof(tables[i].table->null_row);
      copy->strip=0;
      copy->blob_field=0;
      length+=copy->length;
      copy++;
      cache->fields++;
    }
  }

  cache->length=length+blobs*sizeof(char*);
  cache->blobs=blobs;
  *blob_ptr=0;					/* End sequentel */
8472
  size=max(thd->variables.join_buff_size, cache->length);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8473 8474 8475
  if (!(cache->buff=(uchar*) my_malloc(size,MYF(0))))
    DBUG_RETURN(1);				/* Don't use cache */ /* purecov: inspected */
  cache->end=cache->buff+size;
8476
  reset_cache_write(cache);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8477 8478 8479 8480 8481 8482 8483 8484 8485 8486 8487 8488 8489 8490 8491 8492 8493 8494 8495 8496 8497
  DBUG_RETURN(0);
}


static ulong
used_blob_length(CACHE_FIELD **ptr)
{
  uint length,blob_length;
  for (length=0 ; *ptr ; ptr++)
  {
    (*ptr)->blob_length=blob_length=(*ptr)->blob_field->get_length();
    length+=blob_length;
    (*ptr)->blob_field->get_ptr(&(*ptr)->str);
  }
  return length;
}


static bool
store_record_in_cache(JOIN_CACHE *cache)
{
8498
  uint length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8499 8500 8501 8502 8503 8504 8505 8506 8507 8508 8509 8510 8511 8512
  uchar *pos;
  CACHE_FIELD *copy,*end_field;
  bool last_record;

  pos=cache->pos;
  end_field=cache->field+cache->fields;

  length=cache->length;
  if (cache->blobs)
    length+=used_blob_length(cache->blob_ptr);
  if ((last_record=(length+cache->length > (uint) (cache->end - pos))))
    cache->ptr_record=cache->records;

  /*
8513
    There is room in cache. Put record there
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8514 8515 8516 8517 8518 8519 8520 8521
  */
  cache->records++;
  for (copy=cache->field ; copy < end_field; copy++)
  {
    if (copy->blob_field)
    {
      if (last_record)
      {
8522 8523
	copy->blob_field->get_image((char*) pos,copy->length+sizeof(char*), 
				    copy->blob_field->charset());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8524 8525 8526 8527
	pos+=copy->length+sizeof(char*);
      }
      else
      {
8528 8529
	copy->blob_field->get_image((char*) pos,copy->length, // blob length
				    copy->blob_field->charset());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8530 8531 8532 8533 8534 8535 8536 8537 8538 8539 8540 8541 8542
	memcpy(pos+copy->length,copy->str,copy->blob_length);  // Blob data
	pos+=copy->length+copy->blob_length;
      }
    }
    else
    {
      if (copy->strip)
      {
	char *str,*end;
	for (str=copy->str,end= str+copy->length;
	     end > str && end[-1] == ' ' ;
	     end--) ;
	length=(uint) (end-str);
8543 8544 8545
	memcpy(pos+2, str, length);
        int2store(pos, length);
	pos+= length+2;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8546 8547 8548 8549 8550 8551 8552 8553 8554 8555 8556 8557 8558 8559
      }
      else
      {
	memcpy(pos,copy->str,copy->length);
	pos+=copy->length;
      }
    }
  }
  cache->pos=pos;
  return last_record || (uint) (cache->end -pos) < cache->length;
}


static void
8560
reset_cache_read(JOIN_CACHE *cache)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8561 8562 8563
{
  cache->record_nr=0;
  cache->pos=cache->buff;
8564 8565 8566 8567 8568 8569 8570 8571
}


static void reset_cache_write(JOIN_CACHE *cache)
{
  reset_cache_read(cache);
  cache->records= 0;
  cache->ptr_record= (uint) ~0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8572 8573 8574 8575 8576 8577 8578
}


static void
read_cached_record(JOIN_TAB *tab)
{
  uchar *pos;
8579
  uint length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8580 8581 8582 8583 8584 8585 8586 8587 8588 8589 8590 8591 8592 8593
  bool last_record;
  CACHE_FIELD *copy,*end_field;

  last_record=tab->cache.record_nr++ == tab->cache.ptr_record;
  pos=tab->cache.pos;

  for (copy=tab->cache.field,end_field=copy+tab->cache.fields ;
       copy < end_field;
       copy++)
  {
    if (copy->blob_field)
    {
      if (last_record)
      {
8594 8595
	copy->blob_field->set_image((char*) pos,copy->length+sizeof(char*),
				    copy->blob_field->charset());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8596 8597 8598 8599 8600 8601 8602 8603 8604 8605 8606 8607
	pos+=copy->length+sizeof(char*);
      }
      else
      {
	copy->blob_field->set_ptr((char*) pos,(char*) pos+copy->length);
	pos+=copy->length+copy->blob_field->get_length();
      }
    }
    else
    {
      if (copy->strip)
      {
8608 8609
        length= uint2korr(pos);
	memcpy(copy->str, pos+2, length);
8610
	memset(copy->str+length, ' ', copy->length-length);
8611
	pos+= 2 + length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8612 8613 8614 8615 8616 8617 8618 8619 8620 8621 8622 8623 8624 8625 8626 8627 8628 8629 8630 8631 8632
      }
      else
      {
	memcpy(copy->str,pos,copy->length);
	pos+=copy->length;
      }
    }
  }
  tab->cache.pos=pos;
  return;
}


static bool
cmp_buffer_with_ref(JOIN_TAB *tab)
{
  bool diff;
  if (!(diff=tab->ref.key_err))
  {
    memcpy(tab->ref.key_buff2, tab->ref.key_buff, tab->ref.key_length);
  }
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8633 8634
  if ((tab->ref.key_err= cp_buffer_from_ref(tab->join->thd, &tab->ref)) || 
      diff)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8635 8636 8637 8638 8639 8640 8641
    return 1;
  return memcmp(tab->ref.key_buff2, tab->ref.key_buff, tab->ref.key_length)
    != 0;
}


bool
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8642
cp_buffer_from_ref(THD *thd, TABLE_REF *ref)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8643
{
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8644 8645
  enum enum_check_fields save_count_cuted_fields= thd->count_cuted_fields;
  thd->count_cuted_fields= CHECK_FIELD_IGNORE;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8646
  for (store_key **copy=ref->key_copy ; *copy ; copy++)
8647
  {
monty@mysql.com's avatar
monty@mysql.com committed
8648
    if ((*copy)->copy() & 1)
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8649 8650
    {
      thd->count_cuted_fields= save_count_cuted_fields;
monty@mysql.com's avatar
monty@mysql.com committed
8651
      return 1;                                 // Something went wrong
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8652
    }
8653
  }
sergefp@mysql.com's avatar
sergefp@mysql.com committed
8654
  thd->count_cuted_fields= save_count_cuted_fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8655 8656 8657 8658 8659
  return 0;
}


/*****************************************************************************
8660
  Group and order functions
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8661 8662 8663
*****************************************************************************/

/*
8664 8665 8666
  Find order/group item in requested columns and change the item to point at
  it. If item doesn't exists, add it first in the field list
  Return 0 if ok.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8667 8668 8669
*/

static int
8670 8671
find_order_in_list(THD *thd, Item **ref_pointer_array,
		   TABLE_LIST *tables,ORDER *order, List<Item> &fields,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8672 8673
		   List<Item> &all_fields)
{
8674 8675
  Item *it= *order->item;
  if (it->type() == Item::INT_ITEM)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8676
  {						/* Order by position */
8677
    uint count= (uint) it->val_int();
8678
    if (!count || count > fields.elements)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8679 8680
    {
      my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),
8681
		      MYF(0), it->full_name(), thd->where);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8682 8683
      return 1;
    }
8684 8685
    order->item= ref_pointer_array + count-1;
    order->in_field_list= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8686 8687
    return 0;
  }
8688
  uint counter;
8689 8690 8691
  bool unaliased;
  Item **item= find_item_in_list(it, fields, &counter,
                                 REPORT_EXCEPT_NOT_FOUND, &unaliased);
8692 8693 8694
  if (!item)
    return 1;

8695
  if (item != (Item **)not_found_item)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8696
  {
8697 8698 8699 8700 8701 8702 8703 8704
    /*
      If we have found field not by its alias in select list but by its
      original field name, we should additionaly check if we have conflict
      for this name (in case if we would perform lookup in all tables).
    */
    if (unaliased && !it->fixed && it->fix_fields(thd, tables, order->item))
      return 1;

8705
    order->item= ref_pointer_array + counter;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8706 8707 8708
    order->in_field_list=1;
    return 0;
  }
8709

bk@work.mysql.com's avatar
bk@work.mysql.com committed
8710
  order->in_field_list=0;
8711
  /*
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8712 8713 8714 8715
    We check it->fixed because Item_func_group_concat can put
    arguments for which fix_fields already was called.

    'it' reassigned in if condition because fix_field can change it.
8716 8717 8718 8719 8720
  */
  if (!it->fixed &&
      (it->fix_fields(thd, tables, order->item) ||
       (it= *order->item)->check_cols(1) ||
       thd->is_fatal_error))
8721
    return 1;					// Wrong field 
8722

8723 8724 8725 8726
  uint el= all_fields.elements;
  all_fields.push_front(it);		        // Add new field to field list
  ref_pointer_array[el]= it;
  order->item= ref_pointer_array + el;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8727 8728 8729 8730
  return 0;
}

/*
8731 8732
  Change order to point at item in select list. If item isn't a number
  and doesn't exits in the select list, add it the the field list.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8733 8734
*/

8735 8736
int setup_order(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
		List<Item> &fields, List<Item> &all_fields, ORDER *order)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8737 8738 8739 8740
{
  thd->where="order clause";
  for (; order; order=order->next)
  {
8741 8742
    if (find_order_in_list(thd, ref_pointer_array, tables, order, fields,
			   all_fields))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8743 8744 8745 8746 8747 8748
      return 1;
  }
  return 0;
}


monty@mysql.com's avatar
monty@mysql.com committed
8749 8750 8751 8752 8753 8754 8755 8756 8757 8758 8759 8760 8761 8762 8763 8764 8765 8766 8767 8768 8769 8770 8771
/*
  Intitialize the GROUP BY list.

  SYNOPSIS
   setup_group()
   thd			Thread handler
   ref_pointer_array	We store references to all fields that was not in
			'fields' here.   
   fields		All fields in the select part. Any item in 'order'
			that is part of these list is replaced by a pointer
			to this fields.
   all_fields		Total list of all unique fields used by the select.
			All items in 'order' that was not part of fields will
			be added first to this list.
  order			The fields we should do GROUP BY on.
  hidden_group_fields	Pointer to flag that is set to 1 if we added any fields
			to all_fields.

  RETURN
   0  ok
   1  error (probably out of memory)
*/

8772
int
8773 8774 8775
setup_group(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
	    List<Item> &fields, List<Item> &all_fields, ORDER *order,
	    bool *hidden_group_fields)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8776 8777 8778 8779 8780
{
  *hidden_group_fields=0;
  if (!order)
    return 0;				/* Everything is ok */

8781
  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8782 8783 8784 8785 8786 8787 8788 8789 8790
  {
    Item *item;
    List_iterator<Item> li(fields);
    while ((item=li++))
      item->marker=0;			/* Marker that field is not used */
  }
  uint org_fields=all_fields.elements;

  thd->where="group statement";
8791
  for (; order; order=order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8792
  {
8793 8794
    if (find_order_in_list(thd, ref_pointer_array, tables, order, fields,
			   all_fields))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8795 8796 8797 8798 8799 8800 8801 8802 8803
      return 1;
    (*order->item)->marker=1;		/* Mark found */
    if ((*order->item)->with_sum_func)
    {
      my_printf_error(ER_WRONG_GROUP_FIELD, ER(ER_WRONG_GROUP_FIELD),MYF(0),
		      (*order->item)->full_name());
      return 1;
    }
  }
8804
  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8805 8806 8807 8808 8809 8810 8811
  {
    /* Don't allow one to use fields that is not used in GROUP BY */
    Item *item;
    List_iterator<Item> li(fields);

    while ((item=li++))
    {
8812 8813
      if (item->type() != Item::SUM_FUNC_ITEM && !item->marker &&
	  !item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8814 8815 8816 8817 8818 8819 8820 8821 8822 8823 8824 8825 8826 8827
      {
	my_printf_error(ER_WRONG_FIELD_WITH_GROUP,
			ER(ER_WRONG_FIELD_WITH_GROUP),
			MYF(0),item->full_name());
	return 1;
      }
    }
  }
  if (org_fields != all_fields.elements)
    *hidden_group_fields=1;			// group fields is not used
  return 0;
}

/*
8828
  Add fields with aren't used at start of field list. Return FALSE if ok
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8829 8830 8831 8832 8833 8834 8835 8836 8837 8838
*/

static bool
setup_new_fields(THD *thd,TABLE_LIST *tables,List<Item> &fields,
		 List<Item> &all_fields, ORDER *new_field)
{
  Item	  **item;
  DBUG_ENTER("setup_new_fields");

  thd->set_query_id=1;				// Not really needed, but...
8839
  uint counter;
8840
  bool not_used;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8841
  for (; new_field ; new_field= new_field->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8842
  {
8843
    if ((item= find_item_in_list(*new_field->item, fields, &counter,
8844
				 IGNORE_ERRORS, &not_used)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8845 8846 8847 8848
      new_field->item=item;			/* Change to shared Item */
    else
    {
      thd->where="procedure list";
8849
      if ((*new_field->item)->fix_fields(thd, tables, new_field->item))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8850 8851 8852 8853 8854 8855 8856 8857 8858
	DBUG_RETURN(1); /* purecov: inspected */
      all_fields.push_front(*new_field->item);
      new_field->item=all_fields.head_ref();
    }
  }
  DBUG_RETURN(0);
}

/*
8859 8860 8861
  Create a group by that consist of all non const fields. Try to use
  the fields in the order given by 'order' to allow one to optimize
  away 'order by'.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8862 8863 8864
*/

static ORDER *
8865 8866
create_distinct_group(THD *thd, Item **ref_pointer_array,
                      ORDER *order_list, List<Item> &fields, 
8867
		      bool *all_order_by_fields_used)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8868 8869 8870 8871
{
  List_iterator<Item> li(fields);
  Item *item;
  ORDER *order,*group,**prev;
8872
  uint index= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8873

8874
  *all_order_by_fields_used= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8875 8876 8877 8878 8879 8880 8881 8882
  while ((item=li++))
    item->marker=0;			/* Marker that field is not used */

  prev= &group;  group=0;
  for (order=order_list ; order; order=order->next)
  {
    if (order->in_field_list)
    {
8883
      ORDER *ord=(ORDER*) thd->memdup((char*) order,sizeof(ORDER));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8884 8885 8886 8887 8888 8889
      if (!ord)
	return 0;
      *prev=ord;
      prev= &ord->next;
      (*ord->item)->marker=1;
    }
8890 8891
    else
      *all_order_by_fields_used= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8892 8893 8894 8895 8896
  }

  li.rewind();
  while ((item=li++))
  {
8897
    if (!item->const_item() && !item->with_sum_func && !item->marker)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8898
    {
8899
      ORDER *ord=(ORDER*) thd->calloc(sizeof(ORDER));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8900 8901
      if (!ord)
	return 0;
8902 8903 8904 8905 8906 8907
      /*
        We have here only field_list (not all_field_list), so we can use
        simple indexing of ref_pointer_array (order in the array and in the
        list are same)
      */
      ord->item= ref_pointer_array + index;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8908 8909 8910 8911
      ord->asc=1;
      *prev=ord;
      prev= &ord->next;
    }
8912
    index++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8913 8914 8915 8916 8917 8918 8919
  }
  *prev=0;
  return group;
}


/*****************************************************************************
8920
  Update join with count of the different type of fields
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8921 8922 8923
*****************************************************************************/

void
8924 8925
count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
		  bool reset_with_sum_func)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8926 8927 8928 8929
{
  List_iterator<Item> li(fields);
  Item *field;

8930
  param->field_count=param->sum_func_count=param->func_count=
8931
    param->hidden_field_count=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8932 8933 8934 8935 8936 8937 8938 8939 8940 8941 8942 8943 8944 8945 8946 8947 8948 8949 8950 8951 8952 8953 8954 8955 8956
  param->quick_group=1;
  while ((field=li++))
  {
    Item::Type type=field->type();
    if (type == Item::FIELD_ITEM)
      param->field_count++;
    else if (type == Item::SUM_FUNC_ITEM)
    {
      if (! field->const_item())
      {
	Item_sum *sum_item=(Item_sum*) field;
	if (!sum_item->quick_group)
	  param->quick_group=0;			// UDF SUM function
	param->sum_func_count++;

	for (uint i=0 ; i < sum_item->arg_count ; i++)
	{
	  if (sum_item->args[0]->type() == Item::FIELD_ITEM)
	    param->field_count++;
	  else
	    param->func_count++;
	}
      }
    }
    else
8957
    {
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8958
      param->func_count++;
8959 8960 8961
      if (reset_with_sum_func)
	field->with_sum_func=0;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8962 8963 8964 8965 8966 8967 8968 8969 8970 8971 8972 8973 8974 8975 8976
  }
}


/*
  Return 1 if second is a subpart of first argument
  If first parts has different direction, change it to second part
  (group is sorted like order)
*/

static bool
test_if_subpart(ORDER *a,ORDER *b)
{
  for (; a && b; a=a->next,b=b->next)
  {
8977
    if ((*a->item)->eq(*b->item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8978 8979 8980 8981 8982 8983 8984 8985 8986 8987 8988 8989 8990 8991 8992 8993 8994 8995 8996 8997 8998 8999 9000 9001 9002 9003
      a->asc=b->asc;
    else
      return 0;
  }
  return test(!b);
}

/*
  Return table number if there is only one table in sort order
  and group and order is compatible
  else return 0;
*/

static TABLE *
get_sort_by_table(ORDER *a,ORDER *b,TABLE_LIST *tables)
{
  table_map map= (table_map) 0;
  DBUG_ENTER("get_sort_by_table");

  if (!a)
    a=b;					// Only one need to be given
  else if (!b)
    b=a;

  for (; a && b; a=a->next,b=b->next)
  {
9004
    if (!(*a->item)->eq(*b->item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9005 9006 9007
      DBUG_RETURN(0);
    map|=a->item[0]->used_tables();
  }
9008
  if (!map || (map & (RAND_TABLE_BIT | OUTER_REF_TABLE_BIT)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9009 9010
    DBUG_RETURN(0);

9011
  for (; !(map & tables->table->map) ; tables=tables->next) ;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9012 9013 9014 9015 9016 9017 9018 9019 9020 9021 9022 9023
  if (map != tables->table->map)
    DBUG_RETURN(0);				// More than one table
  DBUG_PRINT("exit",("sort by table: %d",tables->table->tablenr));
  DBUG_RETURN(tables->table);
}


	/* calc how big buffer we need for comparing group entries */

static void
calc_group_buffer(JOIN *join,ORDER *group)
{
9024 9025
  uint key_length=0, parts=0, null_parts=0;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
9026 9027 9028 9029
  if (group)
    join->group= 1;
  for (; group ; group=group->next)
  {
9030
    Field *field=(*group->item)->get_tmp_table_field();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9031 9032 9033 9034 9035 9036 9037 9038 9039 9040 9041 9042 9043 9044 9045
    if (field)
    {
      if (field->type() == FIELD_TYPE_BLOB)
	key_length+=MAX_BLOB_WIDTH;		// Can't be used as a key
      else
	key_length+=field->pack_length();
    }
    else if ((*group->item)->result_type() == REAL_RESULT)
      key_length+=sizeof(double);
    else if ((*group->item)->result_type() == INT_RESULT)
      key_length+=sizeof(longlong);
    else
      key_length+=(*group->item)->max_length;
    parts++;
    if ((*group->item)->maybe_null)
9046
      null_parts++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9047
  }
9048
  join->tmp_table_param.group_length=key_length+null_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9049
  join->tmp_table_param.group_parts=parts;
9050
  join->tmp_table_param.group_null_parts=null_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9051 9052
}

9053

9054
/*
9055
  allocate group fields or take prepared (cached)
9056

9057
  SYNOPSIS
9058 9059 9060 9061 9062 9063 9064 9065 9066 9067 9068 9069
    make_group_fields()
    main_join - join of current select
    curr_join - current join (join of current select or temporary copy of it)

  RETURN
    0 - ok
    1 - failed
*/

static bool
make_group_fields(JOIN *main_join, JOIN *curr_join)
{
9070 9071 9072 9073 9074 9075 9076 9077 9078 9079 9080 9081
  if (main_join->group_fields_cache.elements)
  {
    curr_join->group_fields= main_join->group_fields_cache;
    curr_join->sort_and_group= 1;
  }
  else
  {
    if (alloc_group_fields(curr_join, curr_join->group_list))
      return (1);
    main_join->group_fields_cache= curr_join->group_fields;
  }
  return (0);
9082
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9083

9084

bk@work.mysql.com's avatar
bk@work.mysql.com committed
9085
/*
9086 9087
  Get a list of buffers for saveing last group
  Groups are saved in reverse order for easyer check loop
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9088 9089 9090 9091 9092 9093 9094 9095 9096
*/

static bool
alloc_group_fields(JOIN *join,ORDER *group)
{
  if (group)
  {
    for (; group ; group=group->next)
    {
9097
      Item_buff *tmp=new_Item_buff(join->thd, *group->item);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9098 9099 9100 9101 9102 9103 9104 9105 9106 9107 9108 9109
      if (!tmp || join->group_fields.push_front(tmp))
	return TRUE;
    }
  }
  join->sort_and_group=1;			/* Mark for do_select */
  return FALSE;
}


static int
test_if_group_changed(List<Item_buff> &list)
{
9110
  DBUG_ENTER("test_if_group_changed");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9111 9112 9113 9114 9115 9116 9117 9118 9119
  List_iterator<Item_buff> li(list);
  int idx= -1,i;
  Item_buff *buff;

  for (i=(int) list.elements-1 ; (buff=li++) ; i--)
  {
    if (buff->cmp())
      idx=i;
  }
9120 9121
  DBUG_PRINT("info", ("idx: %d", idx));
  DBUG_RETURN(idx);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9122 9123 9124 9125
}


/*
9126
  Setup copy_fields to save fields at start of new group
9127 9128 9129 9130 9131 9132 9133 9134 9135 9136 9137 9138 9139 9140 9141 9142 9143 9144 9145

  setup_copy_fields()
    thd - THD pointer
    param - temporary table parameters
    ref_pointer_array - array of pointers to top elements of filed list
    res_selected_fields - new list of items of select item list
    res_all_fields - new list of all items
    elements - number of elements in select item list
    all_fields - all fields list

  DESCRIPTION
    Setup copy_fields to save fields at start of new group
    Only FIELD_ITEM:s and FUNC_ITEM:s needs to be saved between groups.
    Change old item_field to use a new field with points at saved fieldvalue
    This function is only called before use of send_fields
  
  RETURN
    0 - ok
    !=0 - error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9146 9147 9148
*/

bool
9149 9150
setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
		  Item **ref_pointer_array,
9151 9152
		  List<Item> &res_selected_fields, List<Item> &res_all_fields,
		  uint elements, List<Item> &all_fields)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9153 9154
{
  Item *pos;
9155
  List_iterator_fast<Item> li(all_fields);
9156
  Copy_field *copy= NULL;
9157 9158 9159
  res_selected_fields.empty();
  res_all_fields.empty();
  List_iterator_fast<Item> itr(res_all_fields);
9160
  List<Item> extra_funcs;
9161
  uint i, border= all_fields.elements - elements;
monty@mysql.com's avatar
monty@mysql.com committed
9162
  DBUG_ENTER("setup_copy_fields");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9163

9164 9165
  if (param->field_count && 
      !(copy=param->copy_field= new Copy_field[param->field_count]))
9166
    goto err2;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9167 9168

  param->copy_funcs.empty();
9169
  for (i= 0; (pos= li++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9170
  {
9171 9172
    Field *field;
    char *tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9173 9174
    if (pos->type() == Item::FIELD_ITEM)
    {
9175
      Item_field *item;
9176
      if (!(item= new Item_field(thd, ((Item_field*) pos))))
9177 9178
	goto err;
      pos= item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9179 9180
      if (item->field->flags & BLOB_FLAG)
      {
9181
	if (!(pos= new Item_copy_string(pos)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9182
	  goto err;
9183 9184 9185 9186 9187 9188 9189 9190 9191 9192
       /*
         Item_copy_string::copy for function can call 
         Item_copy_string::val_int for blob via Item_ref.
         But if Item_copy_string::copy for blob isn't called before,
         it's value will be wrong
         so let's insert Item_copy_string for blobs in the beginning of 
         copy_funcs
         (to see full test case look at having.test, BUG #4358) 
       */
	if (param->copy_funcs.push_front(pos))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9193 9194
	  goto err;
      }
9195 9196 9197 9198 9199 9200
      else
      {
	/* 
	   set up save buffer and change result_field to point at 
	   saved value
	*/
9201
	field= item->field;
9202
	item->result_field=field->new_field(thd->mem_root,field->table);
9203 9204 9205 9206 9207 9208
        /*
          We need to allocate one extra byte for null handling and
          another extra byte to not get warnings from purify in
          Field_string::val_int
        */
	tmp= (char*) sql_alloc(field->pack_length()+2);
9209 9210 9211 9212
	if (!tmp)
	  goto err;
	copy->set(tmp, item->result_field);
	item->result_field->move_field(copy->to_ptr,copy->to_null_ptr,1);
9213
#ifdef HAVE_purify
9214
        copy->to_ptr[copy->from_length]= 0;
9215
#endif
9216
        copy++;
9217
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9218 9219
    }
    else if ((pos->type() == Item::FUNC_ITEM ||
9220 9221
	      pos->type() == Item::SUBSELECT_ITEM ||
	      pos->type() == Item::CACHE_ITEM ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9222 9223 9224 9225 9226 9227 9228 9229 9230 9231 9232
	      pos->type() == Item::COND_ITEM) &&
	     !pos->with_sum_func)
    {						// Save for send fields
      /* TODO:
	 In most cases this result will be sent to the user.
	 This should be changed to use copy_int or copy_real depending
	 on how the value is to be used: In some cases this may be an
	 argument in a group function, like: IF(ISNULL(col),0,COUNT(*))
      */
      if (!(pos=new Item_copy_string(pos)))
	goto err;
9233 9234 9235 9236 9237 9238
      if (i < border)                           // HAVING, ORDER and GROUP BY
      {
        if (extra_funcs.push_back(pos))
          goto err;
      }
      else if (param->copy_funcs.push_back(pos))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9239 9240
	goto err;
    }
9241 9242
    res_all_fields.push_back(pos);
    ref_pointer_array[((i < border)? all_fields.elements-i-1 : i-border)]=
9243
      pos;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9244
  }
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
9245
  param->copy_field_end= copy;
9246 9247 9248

  for (i= 0; i < border; i++)
    itr++;
9249
  itr.sublist(res_selected_fields, elements);
9250 9251 9252 9253 9254 9255
  /*
    Put elements from HAVING, ORDER BY and GROUP BY last to ensure that any
    reference used in these will resolve to a item that is already calculated
  */
  param->copy_funcs.concat(&extra_funcs);

bk@work.mysql.com's avatar
bk@work.mysql.com committed
9256 9257 9258
  DBUG_RETURN(0);

 err:
monty@mysql.com's avatar
monty@mysql.com committed
9259 9260
  if (copy)
    delete [] param->copy_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9261
  param->copy_field=0;
9262
err2:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9263 9264 9265 9266 9267
  DBUG_RETURN(TRUE);
}


/*
9268 9269 9270 9271
  Make a copy of all simple SELECT'ed items

  This is done at the start of a new group so that we can retrieve
  these later when the group changes.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9272 9273 9274 9275 9276 9277
*/

void
copy_fields(TMP_TABLE_PARAM *param)
{
  Copy_field *ptr=param->copy_field;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
9278
  Copy_field *end=param->copy_field_end;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9279

9280
  for (; ptr != end; ptr++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9281 9282
    (*ptr->do_copy)(ptr);

sergefp@mysql.com's avatar
sergefp@mysql.com committed
9283
  List_iterator_fast<Item> it(param->copy_funcs);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9284 9285 9286 9287 9288 9289
  Item_copy_string *item;
  while ((item = (Item_copy_string*) it++))
    item->copy();
}


9290 9291
/*
  Make an array of pointers to sum_functions to speed up sum_func calculation
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9292

9293 9294 9295 9296 9297 9298 9299 9300 9301
  SYNOPSIS
    alloc_func_list()

  RETURN
    0	ok
    1	Error
*/

bool JOIN::alloc_func_list()
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9302
{
9303 9304 9305 9306 9307 9308 9309 9310 9311 9312 9313 9314 9315 9316 9317 9318 9319 9320 9321 9322 9323 9324 9325 9326 9327 9328 9329
  uint func_count, group_parts;
  DBUG_ENTER("alloc_func_list");

  func_count= tmp_table_param.sum_func_count;
  /*
    If we are using rollup, we need a copy of the summary functions for
    each level
  */
  if (rollup.state != ROLLUP::STATE_NONE)
    func_count*= (send_group_parts+1);

  group_parts= send_group_parts;
  /*
    If distinct, reserve memory for possible
    disctinct->group_by optimization
  */
  if (select_distinct)
    group_parts+= fields_list.elements;

  /* This must use calloc() as rollup_make_fields depends on this */
  sum_funcs= (Item_sum**) thd->calloc(sizeof(Item_sum**) * (func_count+1) +
				      sizeof(Item_sum***) * (group_parts+1));
  sum_funcs_end= (Item_sum***) (sum_funcs+func_count+1);
  DBUG_RETURN(sum_funcs == 0);
}


9330 9331 9332 9333 9334 9335 9336 9337 9338 9339 9340 9341 9342 9343 9344 9345 9346
/*
  Initialize 'sum_funcs' array with all Item_sum objects

  SYNOPSIS
    make_sum_func_list()
    field_list		All items
    send_fields		Items in select list
    before_group_by	Set to 1 if this is called before GROUP BY handling

  NOTES
    Calls ::setup() for all item_sum objects in field_list

  RETURN
    0  ok
    1  error
*/

9347
bool JOIN::make_sum_func_list(List<Item> &field_list, List<Item> &send_fields,
9348
			      bool before_group_by)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9349
{
9350
  List_iterator_fast<Item> it(field_list);
9351 9352
  Item_sum **func;
  Item *item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9353 9354
  DBUG_ENTER("make_sum_func_list");

9355 9356
  func= sum_funcs;
  while ((item=it++))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9357
  {
9358
    if (item->type() == Item::SUM_FUNC_ITEM && !item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9359
    {
9360
      *func++= (Item_sum*) item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9361
      /* let COUNT(DISTINCT) create the temporary table */
9362
      if (((Item_sum*) item)->setup(thd))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9363 9364 9365
	DBUG_RETURN(TRUE);
    }
  }
9366 9367 9368
  if (before_group_by && rollup.state == ROLLUP::STATE_INITED)
  {
    rollup.state= ROLLUP::STATE_READY;
9369
    if (rollup_make_fields(field_list, send_fields, &func))
9370 9371 9372 9373 9374 9375 9376
      DBUG_RETURN(TRUE);			// Should never happen
  }
  else if (rollup.state == ROLLUP::STATE_NONE)
  {
    for (uint i=0 ; i <= send_group_parts ;i++)
      sum_funcs_end[i]= func;
  }
9377 9378
  else if (rollup.state == ROLLUP::STATE_READY)
    DBUG_RETURN(FALSE);                         // Don't put end marker
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9379 9380 9381 9382 9383 9384
  *func=0;					// End marker
  DBUG_RETURN(FALSE);
}


/*
9385
  Change all funcs and sum_funcs to fields in tmp table, and create
9386 9387 9388 9389 9390 9391 9392 9393 9394 9395 9396 9397 9398
  new list of all items.

  change_to_use_tmp_fields()
    thd - THD pointer
    ref_pointer_array - array of pointers to top elements of filed list
    res_selected_fields - new list of items of select item list
    res_all_fields - new list of all items
    elements - number of elements in select item list
    all_fields - all fields list

   RETURN
    0 - ok
    !=0 - error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9399 9400 9401
*/

static bool
9402
change_to_use_tmp_fields(THD *thd, Item **ref_pointer_array,
9403 9404 9405
			 List<Item> &res_selected_fields,
			 List<Item> &res_all_fields,
			 uint elements, List<Item> &all_fields)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9406
{
9407
  List_iterator_fast<Item> it(all_fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9408
  Item *item_field,*item;
9409 9410
  res_selected_fields.empty();
  res_all_fields.empty();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9411

9412
  uint i, border= all_fields.elements - elements;
9413
  for (i= 0; (item= it++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9414 9415
  {
    Field *field;
9416
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9417
    if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM)
9418 9419
      item_field= item;
    else
9420
    {
9421
      if (item->type() == Item::FIELD_ITEM)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9422
      {
9423
	item_field= item->get_tmp_table_item(thd);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9424
      }
9425
      else if ((field= item->get_tmp_table_field()))
9426 9427 9428 9429
      {
	if (item->type() == Item::SUM_FUNC_ITEM && field->table->group)
	  item_field= ((Item_sum*) item)->result_item(field);
	else
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
9430
	  item_field= (Item*) new Item_field(field);
9431 9432 9433 9434 9435 9436 9437
	if (!item_field)
	  return TRUE;				// Fatal error
	item_field->name= item->name;		/*lint -e613 */
#ifndef DBUG_OFF
	if (_db_on_ && !item_field->name)
	{
	  char buff[256];
9438
	  String str(buff,sizeof(buff),&my_charset_bin);
9439 9440 9441 9442
	  str.length(0);
	  item->print(&str);
	  item_field->name= sql_strmake(str.ptr(),str.length());
	}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9443
#endif
9444 9445 9446
      }
      else
	item_field= item;
9447 9448 9449
    }
    res_all_fields.push_back(item_field);
    ref_pointer_array[((i < border)? all_fields.elements-i-1 : i-border)]=
9450
      item_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9451
  }
9452

9453
  List_iterator_fast<Item> itr(res_all_fields);
9454 9455
  for (i= 0; i < border; i++)
    itr++;
9456
  itr.sublist(res_selected_fields, elements);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9457 9458 9459 9460 9461
  return FALSE;
}


/*
9462 9463
  Change all sum_func refs to fields to point at fields in tmp table
  Change all funcs to be fields in tmp table
9464 9465 9466 9467 9468 9469 9470 9471 9472 9473

  change_refs_to_tmp_fields()
    thd - THD pointer
    ref_pointer_array - array of pointers to top elements of filed list
    res_selected_fields - new list of items of select item list
    res_all_fields - new list of all items
    elements - number of elements in select item list
    all_fields - all fields list

   RETURN
9474 9475
    0	ok
    1	error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9476 9477 9478
*/

static bool
9479
change_refs_to_tmp_fields(THD *thd, Item **ref_pointer_array,
9480 9481 9482
			  List<Item> &res_selected_fields,
			  List<Item> &res_all_fields, uint elements,
			  List<Item> &all_fields)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9483
{
9484
  List_iterator_fast<Item> it(all_fields);
9485
  Item *item, *new_item;
9486 9487
  res_selected_fields.empty();
  res_all_fields.empty();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9488

9489
  uint i, border= all_fields.elements - elements;
9490
  for (i= 0; (item= it++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9491
  {
9492 9493
    res_all_fields.push_back(new_item= item->get_tmp_table_item(thd));
    ref_pointer_array[((i < border)? all_fields.elements-i-1 : i-border)]=
9494
      new_item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9495
  }
9496

9497
  List_iterator_fast<Item> itr(res_all_fields);
9498 9499
  for (i= 0; i < border; i++)
    itr++;
9500
  itr.sublist(res_selected_fields, elements);
9501

9502
  return thd->is_fatal_error;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9503 9504 9505 9506 9507
}



/******************************************************************************
9508
  Code for calculating functions
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9509 9510 9511 9512 9513 9514 9515 9516 9517 9518 9519 9520 9521 9522 9523 9524 9525 9526 9527
******************************************************************************/

static void
init_tmptable_sum_functions(Item_sum **func_ptr)
{
  Item_sum *func;
  while ((func= *(func_ptr++)))
    func->reset_field();
}


	/* Update record 0 in tmp_table from record 1 */

static void
update_tmptable_sum_func(Item_sum **func_ptr,
			 TABLE *tmp_table __attribute__((unused)))
{
  Item_sum *func;
  while ((func= *(func_ptr++)))
9528
    func->update_field();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9529 9530 9531 9532 9533 9534
}


	/* Copy result of sum functions to record in tmp_table */

static void
9535
copy_sum_funcs(Item_sum **func_ptr, Item_sum **end_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9536
{
9537 9538
  for (; func_ptr != end_ptr ; func_ptr++)
    (void) (*func_ptr)->save_in_result_field(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9539 9540 9541 9542
  return;
}


9543 9544
static bool
init_sum_functions(Item_sum **func_ptr, Item_sum **end_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9545
{
9546 9547 9548 9549 9550 9551 9552 9553 9554 9555 9556 9557
  for (; func_ptr != end_ptr ;func_ptr++)
  {
    if ((*func_ptr)->reset())
      return 1;
  }
  /* If rollup, calculate the upper sum levels */
  for ( ; *func_ptr ; func_ptr++)
  {
    if ((*func_ptr)->add())
      return 1;
  }
  return 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9558 9559 9560 9561 9562 9563 9564 9565 9566 9567 9568 9569 9570 9571 9572 9573
}


static bool
update_sum_func(Item_sum **func_ptr)
{
  Item_sum *func;
  for (; (func= (Item_sum*) *func_ptr) ; func_ptr++)
    if (func->add())
      return 1;
  return 0;
}

	/* Copy result of functions to record in tmp_table */

void
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
9574
copy_funcs(Item **func_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9575
{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
9576
  Item *func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9577
  for (; (func = *func_ptr) ; func_ptr++)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
9578
    func->save_in_result_field(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9579 9580 9581
}


9582
/*
9583 9584
  Create a condition for a const reference and add this to the
  currenct select for the table
9585
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9586 9587 9588 9589 9590 9591 9592 9593 9594 9595 9596 9597 9598 9599 9600

static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
{
  DBUG_ENTER("add_ref_to_table_cond");
  if (!join_tab->ref.key_parts)
    DBUG_RETURN(FALSE);

  Item_cond_and *cond=new Item_cond_and();
  TABLE *table=join_tab->table;
  int error;
  if (!cond)
    DBUG_RETURN(TRUE);

  for (uint i=0 ; i < join_tab->ref.key_parts ; i++)
  {
9601 9602
    Field *field=table->field[table->key_info[join_tab->ref.key].key_part[i].
			      fieldnr-1];
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9603
    Item *value=join_tab->ref.items[i];
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
9604
    cond->add(new Item_func_equal(new Item_field(field), value));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9605
  }
9606
  if (thd->is_fatal_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9607
    DBUG_RETURN(TRUE);
9608

9609 9610
  if (!cond->fixed)
    cond->fix_fields(thd,(TABLE_LIST *) 0, (Item**)&cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
9611 9612 9613 9614 9615 9616 9617 9618 9619 9620 9621
  if (join_tab->select)
  {
    error=(int) cond->add(join_tab->select->cond);
    join_tab->select_cond=join_tab->select->cond=cond;
  }
  else if ((join_tab->select=make_select(join_tab->table, 0, 0, cond,&error)))
    join_tab->select_cond=cond;

  DBUG_RETURN(error ? TRUE : FALSE);
}

9622 9623 9624 9625 9626 9627 9628 9629 9630 9631 9632 9633 9634 9635 9636 9637 9638

/*
  Free joins of subselect of this select.

  free_underlaid_joins()
    thd - THD pointer
    select - pointer to st_select_lex which subselects joins we will free
*/

void free_underlaid_joins(THD *thd, SELECT_LEX *select)
{
  for (SELECT_LEX_UNIT *unit= select->first_inner_unit();
       unit;
       unit= unit->next_unit())
    unit->cleanup();
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
9639
/****************************************************************************
9640 9641 9642
  ROLLUP handling
****************************************************************************/

9643 9644 9645 9646 9647 9648 9649 9650 9651 9652 9653 9654 9655 9656
/*
  Replace occurences of group by fields in an expression by ref items

  SYNOPSIS
    change_group_ref()
    thd                  reference to the context
    expr                 expression to make replacement
    group_list           list of references to group by items
    changed        out:  returns 1 if item contains a replaced field item 
     
  DESCRIPTION
    The function replaces occurrences of group by fields in expr
    by ref objects for these fields unless they are under aggregate
    functions.
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9657 9658
    The function also corrects value of the the maybe_null attribute
    for the items of all subexpressions containing group by fields.
9659 9660 9661 9662 9663 9664 9665 9666 9667 9668

  IMPLEMENTATION
    The function recursively traverses the tree of the expr expression,
    looks for occurrences of the group by fields that are not under
    aggregate functions and replaces them for the corresponding ref items.

  NOTES
    This substitution is needed GROUP BY queries with ROLLUP if
    SELECT list contains expressions over group by attributes.

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9669 9670 9671
  TODO: Some functions are not null-preserving. For those functions
    updating of the maybe_null attribute is an overkill. 

9672 9673 9674 9675 9676 9677 9678 9679 9680
  EXAMPLES
    SELECT a+1 FROM t1 GROUP BY a WITH ROLLUP
    SELECT SUM(a)+a FROM t1 GROUP BY a WITH ROLLUP 
    
  RETURN
    0	if ok
    1   on error
*/

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9681
static bool change_group_ref(THD *thd, Item_func *expr, ORDER *group_list,
9682 9683
                             bool *changed)
{
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9684
  if (expr->arg_count)
9685 9686
  {
    Item **arg,**arg_end;
9687
    bool arg_changed= FALSE;
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9688 9689
    for (arg= expr->arguments(),
         arg_end= expr->arguments()+expr->arg_count;
9690 9691 9692 9693 9694 9695 9696 9697 9698 9699 9700 9701 9702 9703
         arg != arg_end; arg++)
    {
      Item *item= *arg;
      if (item->type() == Item::FIELD_ITEM || item->type() == Item::REF_ITEM)
      {
        ORDER *group_tmp;
        for (group_tmp= group_list; group_tmp; group_tmp= group_tmp->next)
        {
          if (item->eq(*group_tmp->item,0))
          {
            Item *new_item;    
            if(!(new_item= new Item_ref(group_tmp->item, 0, item->name)))
              return 1;                                 // fatal_error is set
            thd->change_item_tree(arg, new_item);
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9704
            arg_changed= TRUE;
9705 9706 9707 9708 9709
          }
        }
      }
      else if (item->type() == Item::FUNC_ITEM)
      {
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9710
        if (change_group_ref(thd, (Item_func *) item, group_list, &arg_changed))
9711 9712
          return 1;
      }
9713 9714 9715 9716 9717
    }
    if (arg_changed)
    {
      expr->maybe_null= 1;
      *changed= TRUE;
9718 9719 9720 9721 9722 9723
    }
  }
  return 0;
}


9724 9725 9726 9727 9728 9729 9730 9731 9732 9733 9734 9735 9736 9737 9738 9739
/* Allocate memory needed for other rollup functions */

bool JOIN::rollup_init()
{
  uint i,j;
  Item **ref_array;

  tmp_table_param.quick_group= 0;	// Can't create groups in tmp table
  rollup.state= ROLLUP::STATE_INITED;

  /*
    Create pointers to the different sum function groups
    These are updated by rollup_make_fields()
  */
  tmp_table_param.group_parts= send_group_parts;

9740 9741 9742 9743 9744
  if (!(rollup.null_items= (Item_null_result**) thd->alloc((sizeof(Item*) +
                                                sizeof(Item**) +
                                                sizeof(List<Item>) +
				                ref_pointer_array_size)
				                * send_group_parts )))
9745
    return 1;
9746 9747
  
  rollup.fields= (List<Item>*) (rollup.null_items + send_group_parts);
9748 9749 9750 9751 9752 9753 9754 9755 9756
  rollup.ref_pointer_arrays= (Item***) (rollup.fields + send_group_parts);
  ref_array= (Item**) (rollup.ref_pointer_arrays+send_group_parts);

  /*
    Prepare space for field list for the different levels
    These will be filled up in rollup_make_fields()
  */
  for (i= 0 ; i < send_group_parts ; i++)
  {
9757
    rollup.null_items[i]= new (thd->mem_root) Item_null_result();
9758 9759
    List<Item> *rollup_fields= &rollup.fields[i];
    rollup_fields->empty();
9760 9761
    rollup.ref_pointer_arrays[i]= ref_array;
    ref_array+= all_fields.elements;
9762 9763 9764
  }
  for (i= 0 ; i < send_group_parts; i++)
  {
9765
    for (j=0 ; j < fields_list.elements ; j++)
9766
      rollup.fields[i].push_back(rollup.null_items[i]);
9767
  }
9768
  List_iterator<Item> it(all_fields);
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9769 9770 9771 9772
  Item *item;
  while ((item= it++))
  {
    ORDER *group_tmp;
9773 9774
    bool found_in_group= 0;

igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9775 9776
    for (group_tmp= group_list; group_tmp; group_tmp= group_tmp->next)
    {
9777
      if (*group_tmp->item == item)
9778
      {
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9779
        item->maybe_null= 1;
9780
        found_in_group= 1;
9781 9782 9783 9784 9785 9786 9787 9788 9789 9790 9791 9792 9793 9794 9795 9796 9797 9798 9799 9800 9801 9802 9803 9804 9805 9806
        if (item->const_item())
        {
          /*
            For ROLLUP queries each constant item referenced in GROUP BY list
            is wrapped up into an Item_func object yielding the same value
            as the constant item. The objects of the wrapper class are never
            considered as constant items and besides they inherit all
            properties of the Item_result_field class.
            This wrapping allows us to ensure writing constant items
            into temporary tables whenever the result of the ROLLUP
            operation has to be written into a temporary table, e.g. when
            ROLLUP is used together with DISTINCT in the SELECT list.
            Usually when creating temporary tables for a intermidiate
            result we do not include fields for constant expressions.
	  */           
          Item* new_item= new Item_func_rollup_const(item);
          if (!new_item)
            return 1;
          new_item->fix_fields(thd,0, (Item **) 0);
          thd->change_item_tree(it.ref(), new_item);
          for (ORDER *tmp= group_tmp; tmp; tmp= tmp->next)
          { 
            if (*tmp->item == item)
              thd->change_item_tree(tmp->item, new_item);
          }
        }
9807
      }
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9808
    }
9809
    if (item->type() == Item::FUNC_ITEM && !found_in_group)
9810
    {
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9811
      bool changed= FALSE;
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9812
      if (change_group_ref(thd, (Item_func *) item, group_list, &changed))
9813 9814 9815 9816 9817 9818 9819 9820 9821
        return 1;
      /*
        We have to prevent creation of a field in a temporary table for
        an expression that contains GROUP BY attributes.
        Marking the expression item as 'with_sum_func' will ensure this.
      */ 
      if (changed)
        item->with_sum_func= 1;
    }
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9822
  }
9823 9824 9825 9826 9827 9828 9829 9830 9831
  return 0;
}
  

/*
  Fill up rollup structures with pointers to fields to use

  SYNOPSIS
    rollup_make_fields()
9832 9833
    fields_arg			List of all fields (hidden and real ones)
    sel_fields			Pointer to selected fields
9834 9835 9836 9837 9838 9839 9840 9841 9842 9843 9844
    func			Store here a pointer to all fields

  IMPLEMENTATION:
    Creates copies of item_sum items for each sum level

  RETURN
    0	if ok
	In this case func is pointing to next not used element.
    1   on error
*/

9845
bool JOIN::rollup_make_fields(List<Item> &fields_arg, List<Item> &sel_fields,
9846 9847
			      Item_sum ***func)
{
9848 9849
  List_iterator_fast<Item> it(fields_arg);
  Item *first_field= sel_fields.head();
9850 9851 9852 9853 9854 9855 9856 9857 9858 9859 9860 9861 9862 9863 9864 9865 9866 9867 9868 9869 9870 9871 9872
  uint level;

  /*
    Create field lists for the different levels

    The idea here is to have a separate field list for each rollup level to
    avoid all runtime checks of which columns should be NULL.

    The list is stored in reverse order to get sum function in such an order
    in func that it makes it easy to reset them with init_sum_functions()

    Assuming:  SELECT a, b, c SUM(b) FROM t1 GROUP BY a,b WITH ROLLUP

    rollup.fields[0] will contain list where a,b,c is NULL
    rollup.fields[1] will contain list where b,c is NULL
    ...
    rollup.ref_pointer_array[#] points to fields for rollup.fields[#]
    ...
    sum_funcs_end[0] points to all sum functions
    sum_funcs_end[1] points to all sum functions, except grand totals
    ...
  */

9873
  for (level=0 ; level < send_group_parts ; level++)
9874 9875 9876 9877 9878 9879 9880 9881 9882 9883
  {
    uint i;
    uint pos= send_group_parts - level -1;
    bool real_fields= 0;
    Item *item;
    List_iterator<Item> new_it(rollup.fields[pos]);
    Item **ref_array_start= rollup.ref_pointer_arrays[pos];
    ORDER *start_group;

    /* Point to first hidden field */
9884
    Item **ref_array= ref_array_start + fields_arg.elements-1;
9885 9886 9887 9888 9889 9890 9891 9892 9893 9894 9895 9896 9897 9898 9899 9900 9901 9902 9903 9904 9905 9906 9907 9908 9909 9910 9911 9912 9913 9914 9915 9916 9917 9918 9919 9920

    /* Remember where the sum functions ends for the previous level */
    sum_funcs_end[pos+1]= *func;

    /* Find the start of the group for this level */
    for (i= 0, start_group= group_list ;
	 i++ < pos ;
	 start_group= start_group->next)
      ;

    it.rewind();
    while ((item= it++))
    {
      if (item == first_field)
      {
	real_fields= 1;				// End of hidden fields
	ref_array= ref_array_start;
      }

      if (item->type() == Item::SUM_FUNC_ITEM && !item->const_item())
      {
	/*
	  This is a top level summary function that must be replaced with
	  a sum function that is reset for this level.

	  NOTE: This code creates an object which is not that nice in a
	  sub select.  Fortunately it's not common to have rollup in
	  sub selects.
	*/
	item= item->copy_or_same(thd);
	((Item_sum*) item)->make_unique();
	if (((Item_sum*) item)->setup(thd))
	  return 1;
	*(*func)= (Item_sum*) item;
	(*func)++;
      }
9921
      else 
9922 9923
      {
	/* Check if this is something that is part of this group by */
9924
	ORDER *group_tmp;
9925
	for (group_tmp= start_group, i= pos ;
9926
             group_tmp ; group_tmp= group_tmp->next, i++)
9927
	{
9928
          if (*group_tmp->item == item)
9929 9930 9931 9932 9933
	  {
	    /*
	      This is an element that is used by the GROUP BY and should be
	      set to NULL in this level
	    */
9934
            Item_null_result *null_item;
9935
	    item->maybe_null= 1;		// Value will be null sometimes
9936 9937
            null_item= rollup.null_items[i];
            null_item->result_field= item->get_tmp_table_field();
9938
            item= null_item;
9939 9940 9941 9942 9943 9944 9945 9946 9947 9948 9949 9950 9951 9952 9953 9954 9955 9956 9957 9958 9959 9960 9961 9962 9963 9964 9965 9966 9967 9968 9969 9970 9971 9972 9973 9974 9975 9976 9977 9978 9979 9980 9981 9982 9983 9984 9985 9986
	    break;
	  }
	}
      }
      *ref_array= item;
      if (real_fields)
      {
	(void) new_it++;			// Point to next item
	new_it.replace(item);			// Replace previous
	ref_array++;
      }
      else
	ref_array--;
    }
  }
  sum_funcs_end[0]= *func;			// Point to last function
  return 0;
}

/*
  Send all rollup levels higher than the current one to the client

  SYNOPSIS:
    rollup_send_data()
    idx			Level we are on:
			0 = Total sum level
			1 = First group changed  (a)
			2 = Second group changed (a,b)

  SAMPLE
    SELECT a, b, c SUM(b) FROM t1 GROUP BY a,b WITH ROLLUP

  RETURN
    0	ok
    1   If send_data_failed()
*/

int JOIN::rollup_send_data(uint idx)
{
  uint i;
  for (i= send_group_parts ; i-- > idx ; )
  {
    /* Get reference pointers to sum functions in place */
    memcpy((char*) ref_pointer_array,
	   (char*) rollup.ref_pointer_arrays[i],
	   ref_pointer_array_size);
    if ((!having || having->val_int()))
    {
igor@rurik.mysql.com's avatar
igor@rurik.mysql.com committed
9987
      if (send_records < unit->select_limit_cnt && do_send_rows &&
9988 9989 9990 9991 9992 9993 9994 9995 9996 9997
	  result->send_data(rollup.fields[i]))
	return 1;
      send_records++;
    }
  }
  /* Restore ref_pointer_array */
  set_items_ref_array(current_ref_pointer_array);
  return 0;
}

9998 9999 10000 10001 10002 10003 10004 10005 10006 10007 10008 10009 10010 10011 10012 10013 10014 10015 10016 10017 10018 10019 10020 10021 10022 10023 10024 10025 10026 10027 10028 10029 10030 10031 10032 10033 10034 10035 10036 10037 10038 10039 10040 10041 10042 10043 10044 10045 10046 10047 10048 10049
/*
  Write all rollup levels higher than the current one to a temp table

  SYNOPSIS:
    rollup_write_data()
    idx                 Level we are on:
                        0 = Total sum level
                        1 = First group changed  (a)
                        2 = Second group changed (a,b)
    table               reference to temp table

  SAMPLE
    SELECT a, b, SUM(c) FROM t1 GROUP BY a,b WITH ROLLUP

  RETURN
    0	ok
    1   if write_data_failed()
*/

int JOIN::rollup_write_data(uint idx, TABLE *table)
{
  uint i;
  for (i= send_group_parts ; i-- > idx ; )
  {
    /* Get reference pointers to sum functions in place */
    memcpy((char*) ref_pointer_array,
	   (char*) rollup.ref_pointer_arrays[i],
	   ref_pointer_array_size);
    if ((!having || having->val_int()))
    {
      int error;
      Item *item;
      List_iterator_fast<Item> it(rollup.fields[i]);
      while ((item= it++))
      {
        if (item->type() == Item::NULL_ITEM && item->is_result_field())
          item->save_in_result_field(1);
      }
      copy_sum_funcs(sum_funcs_end[i+1], sum_funcs_end[i]);
      if ((error= table->file->write_row(table->record[0])))
      {
	if (create_myisam_from_heap(thd, table, &tmp_table_param,
				      error, 0))
	  return 1;		     
      }
    }
  }
  /* Restore ref_pointer_array */
  set_items_ref_array(current_ref_pointer_array);
  return 0;
}

10050 10051 10052 10053 10054 10055 10056 10057 10058 10059 10060 10061 10062 10063 10064 10065 10066 10067 10068 10069
/*
  clear results if there are not rows found for group
  (end_send_group/end_write_group)

  SYNOPSYS
     JOIN::clear()
*/

void JOIN::clear()
{
  clear_tables(this);
  copy_fields(&tmp_table_param);

  if (sum_funcs)
  {
    Item_sum *func, **func_ptr= sum_funcs;
    while ((func= *(func_ptr++)))
      func->clear();
  }
}
10070

bk@work.mysql.com's avatar
bk@work.mysql.com committed
10071
/****************************************************************************
10072 10073
  EXPLAIN handling

10074
  Send a description about what how the select will be done to stdout
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10075 10076
****************************************************************************/

monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
10077
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
10078
			    bool distinct,const char *message)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10079 10080
{
  List<Item> field_list;
10081
  List<Item> item_list;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
10082
  THD *thd=join->thd;
10083
  select_result *result=join->result;
10084
  Item *item_null= new Item_null();
10085
  CHARSET_INFO *cs= system_charset_info;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
10086
  DBUG_ENTER("select_describe");
10087
  DBUG_PRINT("info", ("Select 0x%lx, type %s, message %s",
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10088
		      (ulong)join->select_lex, join->select_lex->type,
10089
		      message ? message : "NULL"));
10090
  /* Don't log this into the slow query log */
10091
  thd->server_status&= ~(SERVER_QUERY_NO_INDEX_USED | SERVER_QUERY_NO_GOOD_INDEX_USED);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10092
  join->unit->offset_limit_cnt= 0;
10093

10094
  if (message)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10095
  {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10096
    item_list.push_back(new Item_int((int32)
10097
				     join->select_lex->select_number));
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10098
    item_list.push_back(new Item_string(join->select_lex->type,
10099
					strlen(join->select_lex->type), cs));
10100
    for (uint i=0 ; i < 7; i++)
10101
      item_list.push_back(item_null);
10102
    item_list.push_back(new Item_string(message,strlen(message),cs));
10103
    if (result->send_data(item_list))
10104
      join->error= 1;
10105
  }
10106 10107 10108
  else if (join->select_lex == join->unit->fake_select_lex)
  {
    /* 
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10109 10110 10111 10112 10113
      here we assume that the query will return at least two rows, so we
      show "filesort" in EXPLAIN. Of course, sometimes we'll be wrong
      and no filesort will be actually done, but executing all selects in
      the UNION to provide precise EXPLAIN information will hardly be
      appreciated :)
10114
    */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10115
    char table_name_buffer[NAME_LEN];
10116 10117
    item_list.empty();
    /* id */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10118
    item_list.push_back(new Item_null);
10119 10120 10121 10122 10123
    /* select_type */
    item_list.push_back(new Item_string(join->select_lex->type,
					strlen(join->select_lex->type),
					cs));
    /* table */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10124 10125 10126 10127 10128 10129 10130 10131 10132 10133 10134 10135 10136 10137 10138 10139 10140 10141 10142 10143 10144 10145 10146
    {
      SELECT_LEX *sl= join->unit->first_select();
      uint len= 6, lastop= 0;
      memcpy(table_name_buffer, "<union", 6);
      for (; sl && len + lastop + 5 < NAME_LEN; sl= sl->next_select())
      {
        len+= lastop;
        lastop= my_snprintf(table_name_buffer + len, NAME_LEN - len,
                            "%u,", sl->select_number);
      }
      if (sl || len + lastop >= NAME_LEN)
      {
        memcpy(table_name_buffer + len, "...>", 5);
        len+= 4;
      }
      else
      {
        len+= lastop;
        table_name_buffer[len - 1]= '>';  // change ',' to '>'
      }
      item_list.push_back(new Item_string(table_name_buffer, len, cs));
    }
    /* type */
10147 10148 10149 10150 10151 10152 10153 10154 10155 10156 10157 10158 10159 10160 10161 10162 10163 10164 10165 10166 10167 10168 10169
    item_list.push_back(new Item_string(join_type_str[JT_ALL],
					  strlen(join_type_str[JT_ALL]),
					  cs));
    /* possible_keys */
    item_list.push_back(item_null);
    /* key*/
    item_list.push_back(item_null);
    /* key_len */
    item_list.push_back(item_null);
    /* ref */
    item_list.push_back(item_null);
    /* rows */
    item_list.push_back(item_null);
    /* extra */
    if (join->unit->global_parameters->order_list.first)
      item_list.push_back(new Item_string("Using filesort",
					  14, cs));
    else
      item_list.push_back(new Item_string("", 0, cs));

    if (result->send_data(item_list))
      join->error= 1;
  }
10170 10171 10172 10173
  else
  {
    table_map used_tables=0;
    for (uint i=0 ; i < join->tables ; i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10174
    {
10175 10176
      JOIN_TAB *tab=join->join_tab+i;
      TABLE *table=tab->table;
10177
      char buff[512],*buff_ptr=buff;
10178
      char buff1[512], buff2[512];
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10179
      char table_name_buffer[NAME_LEN];
10180 10181
      String tmp1(buff1,sizeof(buff1),cs);
      String tmp2(buff2,sizeof(buff2),cs);
10182 10183 10184
      tmp1.length(0);
      tmp2.length(0);

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10185
      item_list.empty();
10186
      /* id */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10187
      item_list.push_back(new Item_uint((uint32)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10188
				       join->select_lex->select_number));
10189
      /* select_type */
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10190 10191
      item_list.push_back(new Item_string(join->select_lex->type,
					  strlen(join->select_lex->type),
10192
					  cs));
10193 10194
      if (tab->type == JT_ALL && tab->select && tab->select->quick)
	tab->type= JT_RANGE;
10195
      /* table */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
10196
      if (table->derived_select_number)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10197
      {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
10198
	/* Derived table name generation */
10199
	int len= my_snprintf(table_name_buffer, sizeof(table_name_buffer)-1,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
10200
			     "<derived%u>",
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10201
			     table->derived_select_number);
10202
	item_list.push_back(new Item_string(table_name_buffer, len, cs));
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10203 10204 10205 10206
      }
      else
	item_list.push_back(new Item_string(table->table_name,
					    strlen(table->table_name),
10207
					    cs));
10208
      /* type */
10209 10210
      item_list.push_back(new Item_string(join_type_str[tab->type],
					  strlen(join_type_str[tab->type]),
10211
					  cs));
10212
      uint j;
10213
      /* possible_keys */
10214
      if (!tab->keys.is_clear_all())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10215
      {
serg@serg.mylan's avatar
serg@serg.mylan committed
10216
        for (j=0 ; j < table->keys ; j++)
10217 10218 10219 10220 10221
        {
          if (tab->keys.is_set(j))
          {
            if (tmp1.length())
              tmp1.append(',');
10222 10223 10224
            tmp1.append(table->key_info[j].name, 
			strlen(table->key_info[j].name),
			system_charset_info);
10225 10226
          }
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10227
      }
10228
      if (tmp1.length())
10229
	item_list.push_back(new Item_string(tmp1.ptr(),tmp1.length(),cs));
10230
      else
10231
	item_list.push_back(item_null);
10232
      /* key key_len ref */
10233
      if (tab->ref.key_parts)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10234
      {
10235 10236
	KEY *key_info=table->key_info+ tab->ref.key;
	item_list.push_back(new Item_string(key_info->name,
10237 10238
					    strlen(key_info->name),
					    system_charset_info));
10239
	item_list.push_back(new Item_int((int32) tab->ref.key_length));
10240 10241
	for (store_key **ref=tab->ref.key_copy ; *ref ; ref++)
	{
10242 10243
	  if (tmp2.length())
	    tmp2.append(',');
10244 10245
	  tmp2.append((*ref)->name(), strlen((*ref)->name()),
		      system_charset_info);
10246
	}
10247
	item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length(),cs));
10248 10249 10250
      }
      else if (tab->type == JT_NEXT)
      {
10251 10252
	KEY *key_info=table->key_info+ tab->index;
	item_list.push_back(new Item_string(key_info->name,
10253
					    strlen(key_info->name),cs));
10254 10255
	item_list.push_back(new Item_int((int32) key_info->key_length));
	item_list.push_back(item_null);
10256 10257 10258
      }
      else if (tab->select && tab->select->quick)
      {
10259 10260
	KEY *key_info=table->key_info+ tab->select->quick->index;
	item_list.push_back(new Item_string(key_info->name,
10261
					    strlen(key_info->name),cs));
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
10262 10263
	item_list.push_back(new Item_int((int32) tab->select->quick->
					 max_used_key_length));
10264
	item_list.push_back(item_null);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10265 10266 10267
      }
      else
      {
10268 10269 10270
	item_list.push_back(item_null);
	item_list.push_back(item_null);
	item_list.push_back(item_null);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10271
      }
10272
      /* rows */
10273 10274 10275
      item_list.push_back(new Item_int((longlong) (ulonglong)
				       join->best_positions[i]. records_read,
				       21));
10276
      /* extra */
10277
      my_bool key_read=table->key_read;
10278 10279
      if ((tab->type == JT_NEXT || tab->type == JT_CONST) &&
          table->used_keys.is_set(tab->index))
10280
	key_read=1;
10281

10282
      if (tab->info)
10283
	item_list.push_back(new Item_string(tab->info,strlen(tab->info),cs));
10284
      else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10285
      {
10286
	if (tab->select)
10287
	{
10288 10289
	  if (tab->use_quick == 2)
	  {
10290
            char buf[MAX_KEY/8+1];
serg@serg.mylan's avatar
serg@serg.mylan committed
10291
	    sprintf(buff_ptr,"; Range checked for each record (index map: 0x%s)",
10292
                tab->keys.print(buf));
10293 10294 10295 10296
	    buff_ptr=strend(buff_ptr);
	  }
	  else
	    buff_ptr=strmov(buff_ptr,"; Using where");
10297
	}
10298 10299 10300 10301 10302 10303 10304 10305 10306 10307 10308 10309 10310 10311
	if (key_read)
	  buff_ptr= strmov(buff_ptr,"; Using index");
	if (table->reginfo.not_exists_optimize)
	  buff_ptr= strmov(buff_ptr,"; Not exists");
	if (need_tmp_table)
	{
	  need_tmp_table=0;
	  buff_ptr= strmov(buff_ptr,"; Using temporary");
	}
	if (need_order)
	{
	  need_order=0;
	  buff_ptr= strmov(buff_ptr,"; Using filesort");
	}
10312
	if (distinct & test_all_bits(used_tables,thd->used_tables))
10313 10314
	  buff_ptr= strmov(buff_ptr,"; Distinct");
	if (buff_ptr == buff)
10315 10316
	  buff_ptr+= 2;				// Skip inital "; "
	item_list.push_back(new Item_string(buff+2,(uint) (buff_ptr - buff)-2,
10317
					    cs));
10318 10319 10320
      }
      // For next iteration
      used_tables|=table->map;
10321
      if (result->send_data(item_list))
10322
	join->error= 1;
10323
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10324
  }
10325 10326 10327 10328 10329 10330 10331
  for (SELECT_LEX_UNIT *unit= join->select_lex->first_inner_unit();
       unit;
       unit= unit->next_unit())
  {
    if (mysql_explain_union(thd, unit, result))
      DBUG_VOID_RETURN;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
10332 10333 10334
  DBUG_VOID_RETURN;
}

10335

10336 10337
int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
{
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10338
  DBUG_ENTER("mysql_explain_union");
10339 10340
  int res= 0;
  SELECT_LEX *first= unit->first_select();
10341

10342 10343 10344 10345
  for (SELECT_LEX *sl= first;
       sl;
       sl= sl->next_select())
  {
10346 10347
    // drop UNCACHEABLE_EXPLAIN, because it is for internal usage only
    uint8 uncacheable= (sl->uncacheable & ~UNCACHEABLE_EXPLAIN);
10348 10349 10350 10351 10352 10353 10354 10355 10356 10357 10358 10359 10360 10361 10362 10363 10364 10365
    sl->type= (((&thd->lex->select_lex)==sl)?
	       ((thd->lex->all_selects_list != sl) ? 
		primary_key_name : "SIMPLE"):
	       ((sl == first)?
		((sl->linkage == DERIVED_TABLE_TYPE) ?
		 "DERIVED":
		 ((uncacheable & UNCACHEABLE_DEPENDENT) ?
		  "DEPENDENT SUBQUERY":
		  (uncacheable?"UNCACHEABLE SUBQUERY":
		   "SUBQUERY"))):
		((uncacheable & UNCACHEABLE_DEPENDENT) ?
		 "DEPENDENT UNION":
		 uncacheable?"UNCACHEABLE UNION":
		 "UNION")));
    sl->options|= SELECT_DESCRIBE;
  }
  if (first->next_select())
  {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10366
    unit->fake_select_lex->select_number= UINT_MAX; // jost for initialization
10367 10368
    unit->fake_select_lex->type= "UNION RESULT";
    unit->fake_select_lex->options|= SELECT_DESCRIBE;
10369 10370
    if (!(res= unit->prepare(thd, result, SELECT_NO_UNLOCK | SELECT_DESCRIBE,
                             "")))
10371 10372 10373 10374 10375 10376 10377 10378 10379 10380 10381 10382 10383 10384 10385 10386 10387 10388
      res= unit->exec();
    res|= unit->cleanup();
  }
  else
  {
    thd->lex->current_select= first;
    res= mysql_select(thd, &first->ref_pointer_array,
			(TABLE_LIST*) first->table_list.first,
			first->with_wild, first->item_list,
			first->where,
			first->order_list.elements +
			first->group_list.elements,
			(ORDER*) first->order_list.first,
			(ORDER*) first->group_list.first,
			first->having,
			(ORDER*) thd->lex->proc_list.first,
			first->options | thd->options | SELECT_DESCRIBE,
			result, unit, first);
10389
  }
10390 10391
  if (res > 0 || thd->net.report_error)
    res= -1; // mysql_explain_select do not report error
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
10392
  DBUG_RETURN(res);
10393 10394
}

10395

10396 10397 10398 10399 10400
void st_select_lex::print(THD *thd, String *str)
{
  if (!thd)
    thd= current_thd;

10401
  str->append("select ", 7);
10402 10403 10404
  
  //options
  if (options & SELECT_STRAIGHT_JOIN)
10405
    str->append("straight_join ", 14);
10406
  if ((thd->lex->lock_option == TL_READ_HIGH_PRIORITY) &&
10407
      (this == &thd->lex->select_lex))
10408
    str->append("high_priority ", 14);
10409
  if (options & SELECT_DISTINCT)
10410
    str->append("distinct ", 9);
10411
  if (options & SELECT_SMALL_RESULT)
10412
    str->append("sql_small_result ", 17);
10413
  if (options & SELECT_BIG_RESULT)
10414
    str->append("sql_big_result ", 15);
10415
  if (options & OPTION_BUFFER_RESULT)
10416
    str->append("sql_buffer_result ", 18);
10417
  if (options & OPTION_FOUND_ROWS)
10418
    str->append("sql_calc_found_rows ", 20);
10419
  if (!thd->lex->safe_to_cache_query)
10420
    str->append("sql_no_cache ", 13);
10421
  if (options & OPTION_TO_QUERY_CACHE)
10422
    str->append("sql_cache ", 10);
10423 10424 10425 10426 10427 10428 10429 10430 10431 10432 10433 10434 10435 10436 10437 10438 10439 10440 10441 10442

  //Item List
  bool first= 1;
  List_iterator_fast<Item> it(item_list);
  Item *item;
  while ((item= it++))
  {
    if (first)
      first= 0;
    else
      str->append(',');
    item->print_item_w_name(str);
  }

  /*
    from clause
    TODO: support USING/FORCE/IGNORE index
  */
  if (table_list.elements)
  {
10443
    str->append(" from ", 6);
10444 10445 10446 10447 10448 10449 10450 10451 10452 10453 10454 10455 10456 10457 10458 10459 10460
    Item *next_on= 0;
    for (TABLE_LIST *table= (TABLE_LIST *) table_list.first;
	 table;
	 table= table->next)
    {
      if (table->derived)
      {
	str->append('(');
	table->derived->print(str);
	str->append(") ");
	str->append(table->alias);
      }
      else
      {
	str->append(table->db);
	str->append('.');
	str->append(table->real_name);
10461
	if (my_strcasecmp(table_alias_charset, table->real_name, table->alias))
10462 10463 10464 10465 10466 10467 10468 10469 10470 10471 10472 10473
	{
	  str->append(' ');
	  str->append(table->alias);
	}
      }

      if (table->on_expr && ((table->outer_join & JOIN_TYPE_LEFT) ||
			     !(table->outer_join & JOIN_TYPE_RIGHT)))
	next_on= table->on_expr;

      if (next_on)
      {
10474
	str->append(" on(", 4);
10475 10476 10477 10478 10479
	next_on->print(str);
	str->append(')');
	next_on= 0;
      }

10480 10481
      TABLE_LIST *next_table;
      if ((next_table= table->next))
10482 10483 10484
      {
	if (table->outer_join & JOIN_TYPE_RIGHT)
	{
10485
	  str->append(" right join ", 12);
10486 10487 10488 10489
	  if (!(table->outer_join & JOIN_TYPE_LEFT) &&
	      table->on_expr)
	    next_on= table->on_expr;	    
	}
10490
	else if (next_table->straight)
10491
	  str->append(" straight_join ", 15);
10492
	else if (next_table->outer_join & JOIN_TYPE_LEFT)
10493
	  str->append(" left join ", 11);
10494
	else
10495
	  str->append(" join ", 6);
10496 10497 10498 10499
      }
    }
  }

10500 10501
  // Where
  Item *cur_where= where;
10502
  if (join)
10503 10504
    cur_where= join->conds;
  if (cur_where)
10505
  {
10506
    str->append(" where ", 7);
10507
    cur_where->print(str);
10508 10509
  }

10510
  // group by & olap
10511 10512
  if (group_list.elements)
  {
10513
    str->append(" group by ", 10);
10514 10515 10516 10517
    print_order(str, (ORDER *) group_list.first);
    switch (olap)
    {
      case CUBE_TYPE:
10518
	str->append(" with cube", 10);
10519 10520
	break;
      case ROLLUP_TYPE:
10521
	str->append(" with rollup", 12);
10522 10523 10524 10525 10526 10527
	break;
      default:
	;  //satisfy compiler
    }
  }

10528 10529
  // having
  Item *cur_having= having;
10530
  if (join)
10531
    cur_having= join->having;
10532

10533
  if (cur_having)
10534
  {
10535
    str->append(" having ", 8);
10536
    cur_having->print(str);
10537 10538 10539 10540
  }

  if (order_list.elements)
  {
10541
    str->append(" order by ", 10);
10542 10543 10544 10545 10546 10547 10548 10549
    print_order(str, (ORDER *) order_list.first);
  }

  // limit
  print_limit(thd, str);

  // PROCEDURE unsupported here
}
10550 10551 10552 10553 10554 10555 10556 10557 10558 10559 10560 10561 10562 10563 10564 10565 10566 10567 10568 10569 10570 10571 10572 10573


/*
  change select_result object of JOIN

  SYNOPSIS
    JOIN::change_result()
    res		new select_result object

  RETURN
    0 - OK
    -1 - error
*/

int JOIN::change_result(select_result *res)
{
  DBUG_ENTER("JOIN::change_result");
  result= res;
  if (!procedure && result->prepare(fields_list, select_lex->master_unit()))
  {
    DBUG_RETURN(-1);
  }
  DBUG_RETURN(0);
}