sql_select.cc 242 KB
Newer Older
1
/* Copyright (C) 2000-2003 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 20 21 22 23 24 25

   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 */

#ifdef __GNUC__
#pragma implementation				// gcc: Class implementation
#endif

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

27
#include "opt_ft.h"
sasha@mysql.sashanet.com's avatar
sasha@mysql.sashanet.com committed
28

bk@work.mysql.com's avatar
bk@work.mysql.com committed
29 30 31 32 33
#include <m_ctype.h>
#include <hash.h>
#include <ft_global.h>

const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
34
			      "MAYBE_REF","ALL","range","index","fulltext",
35
			      "ref_or_null","simple_in","index_in"
36
};
bk@work.mysql.com's avatar
bk@work.mysql.com committed
37

38
static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
39
static bool make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
40
				 DYNAMIC_ARRAY *keyuse);
41 42
static bool update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,
				JOIN_TAB *join_tab,
43 44
                                uint tables, COND *conds,
				table_map table_map, SELECT_LEX *select_lex);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
45 46
static int sort_keyuse(KEYUSE *a,KEYUSE *b);
static void set_position(JOIN *join,uint index,JOIN_TAB *table,KEYUSE *key);
47 48
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
49 50 51 52 53 54
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);
55 56
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
57 58 59 60 61
				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);
62
static void join_free(JOIN *join, bool full);
63
static bool only_eq_ref_tables(JOIN *join, ORDER *order, table_map tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
64 65 66 67
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,
			   bool *simple_order);
68
static int return_zero_rows(JOIN *join, select_result *res,TABLE_LIST *tables,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
69 70
			    List<Item> &fields, bool send_row,
			    uint select_options, const char *info,
71 72
			    Item *having, Procedure *proc,
			    SELECT_LEX_UNIT *unit);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
73 74 75 76 77
static COND *optimize_cond(COND *conds,Item::cond_result *cond_value);
static COND *remove_eq_conds(COND *cond,Item::cond_result *cond_value);
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,
78
				    ulong options);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
79 80 81 82 83 84 85 86 87 88 89 90 91 92
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);
static int flush_cached_records(JOIN *join,JOIN_TAB *join_tab,bool skipp_last);
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);
93
static int join_read_const_table(JOIN_TAB *tab, POSITION *pos);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
94 95 96 97
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);
98
static int join_read_last_key(JOIN_TAB *tab);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
99 100 101 102 103
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);
104 105 106 107 108 109
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
110 111
static int join_ft_read_first(JOIN_TAB *tab);
static int join_ft_read_next(READ_RECORD *info);
112 113
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
114 115 116 117 118
static COND *make_cond_for_table(COND *cond,table_map table,
				 table_map used_table);
static Item* part_of_refkey(TABLE *form,Field *field);
static uint find_shortest_key(TABLE *table, key_map usable_keys);
static bool test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,
119
				    ha_rows select_limit, bool no_changes);
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
120 121
static int create_sort_index(THD *thd, JOIN_TAB *tab,ORDER *order,
			     ha_rows filesort_limit, ha_rows select_limit);
122
static int create_sort_index(THD *thd, JOIN_TAB *tab,ORDER *order,
123
			     ha_rows select_limit);
124 125
static int remove_duplicates(JOIN *join,TABLE *entry,List<Item> &fields,
			     Item *having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
126
static int remove_dup_with_compare(THD *thd, TABLE *entry, Field **field,
127
				   ulong offset,Item *having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
128 129
static int remove_dup_with_hash_index(THD *thd, TABLE *table,
				      uint field_count, Field **first_field,
130
				      ulong key_length,Item *having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
131 132 133 134 135 136 137 138
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);
static void reset_cache(JOIN_CACHE *cache);
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);
139 140 141
static ORDER *create_distinct_group(THD *thd, ORDER *order,
				    List<Item> &fields,
				    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
157 158 159 160
static void init_tmptable_sum_functions(Item_sum **func);
static void update_tmptable_sum_func(Item_sum **func,TABLE *tmp_table);
static void copy_sum_funcs(Item_sum **func_ptr);
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);
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
163
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
164
			    bool distinct, const char *message=NullS);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
165

166

167 168 169 170 171 172 173 174
/*
  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;
175
  fix_tables_pointers(lex->all_selects_list);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
176
  if (select_lex->next_select())
177
    res=mysql_union(thd, lex, result, &lex->unit, 0);
178
  else
179 180 181 182 183 184 185 186 187 188 189
    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,
190
		      result, &(lex->unit), &(lex->select_lex), 0);
191 192
  if (res && result)
    result->abort();
193

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
194 195
  if (res || thd->net.report_error)
  {
196
    send_error(thd, 0, NullS);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
197 198
    res= 1;
  }
199 200 201 202
  delete result;
  return res;
}

203 204 205 206 207 208

void relink_tables(SELECT_LEX *select_lex)
{
  for (TABLE_LIST *cursor= (TABLE_LIST *) select_lex->table_list.first;
       cursor;
       cursor=cursor->next)
209 210
    if (cursor->table_list)
      cursor->table= cursor->table_list->table;
211 212 213
}


bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
214 215 216 217 218 219 220 221
void fix_tables_pointers(SELECT_LEX *select_lex)
{
  if (select_lex->next_select_in_list())
  {
    /* Fix tables 'to-be-unioned-from' list to point at opened tables */
    for (SELECT_LEX *sl= select_lex;
	 sl;
	 sl= sl->next_select_in_list())
222
      relink_tables(sl);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
223 224
  }
}
225

226 227 228 229 230
void fix_tables_pointers(SELECT_LEX_UNIT *unit)
{
  for (SELECT_LEX *sl= unit->first_select(); sl; sl= sl->next_select())
  {
    relink_tables(sl);
231
    for (SELECT_LEX_UNIT *un= sl->first_inner_unit(); un; un= un->next_unit())
232 233 234 235
      fix_tables_pointers(un);
  }
}

236

237
/*
238
  Function to setup clauses without sum functions
239
*/
240 241
inline int setup_without_group(THD *thd, Item **ref_pointer_array,
			       TABLE_LIST *tables,
242 243 244 245 246 247 248 249
			       List<Item> &fields,
			       List<Item> &all_fields,
			       COND **conds,
			       ORDER *order,
			       ORDER *group, bool *hidden_group_fields)
{
  bool save_allow_sum_func= thd->allow_sum_func;
  thd->allow_sum_func= 0;
250 251 252 253 254
  int 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));
255 256 257 258
  thd->allow_sum_func= save_allow_sum_func;
  return res;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
259
/*****************************************************************************
260 261
  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
262 263
*****************************************************************************/

264 265 266 267 268
/*
  Prepare of whole select (including subselect in future).
  return -1 on error
          0 on success
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
269
int
270 271 272 273
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
274
	      Item *having_init,
275
	      ORDER *proc_param_init, SELECT_LEX *select,
276
	      SELECT_LEX_UNIT *unit,
277
	      bool tables_and_fields_initied)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
278
{
279
  DBUG_ENTER("JOIN::prepare");
280

281 282 283 284 285 286
  conds= conds_init;
  order= order_init;
  group_list= group_init;
  having= having_init;
  proc_param= proc_param_init;
  tables_list= tables_init;
287
  select_lex= select;
288
  select_lex->join= this;
289
  union_part= (unit->first_select()->next_select() != 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
290 291 292

  /* Check that all tables, fields, conds and order are ok */

293 294 295 296
  if ((tables_and_fields_initied ? 0 : (setup_tables(tables_list) ||
					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
297
      select_lex->setup_ref_array(thd, og_num) ||
298 299 300 301 302
      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
303 304
    DBUG_RETURN(-1);				/* purecov: inspected */

305
  ref_pointer_array= *rref_pointer_array;
306
  
bk@work.mysql.com's avatar
bk@work.mysql.com committed
307 308 309 310
  if (having)
  {
    thd->where="having clause";
    thd->allow_sum_func=1;
311
    select_lex->having_fix_field= 1;
312 313
    bool having_fix_rc= (having->fix_fields(thd, tables_list, &having) ||
			 having->check_cols(1));
314
    select_lex->having_fix_field= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
315
    if (having_fix_rc || thd->net.report_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
316 317
      DBUG_RETURN(-1);				/* purecov: inspected */
    if (having->with_sum_func)
318
      having->split_sum_func(ref_pointer_array, all_fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
319
  }
320

321 322 323 324
  // Is it subselect
  {
    Item_subselect *subselect;
    if ((subselect= select_lex->master_unit()->item) &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
325
	select_lex->linkage != GLOBAL_OPTIONS_TYPE)
326 327
    {
      Item_subselect::trans_res res;
328
      if ((res= subselect->select_transformer(this)) !=
329 330 331 332 333
	  Item_subselect::OK)
	DBUG_RETURN((res == Item_subselect::ERROR));
    }
  }

334
  if (setup_ftfuncs(select_lex)) /* should be after having->fix_fields */
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
335
    DBUG_RETURN(-1);
336 337
  

bk@work.mysql.com's avatar
bk@work.mysql.com committed
338 339 340 341 342
  /*
    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;
343
  */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
344
  {
345
    if (!group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
346 347
    {
      uint flag=0;
348
      List_iterator_fast<Item> it(fields_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
349 350 351 352 353
      Item *item;
      while ((item= it++))
      {
	if (item->with_sum_func)
	  flag|=1;
monty@donna.mysql.fi's avatar
monty@donna.mysql.fi committed
354
	else if (!(flag & 2) && !item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
355 356 357 358 359 360 361 362 363
	  flag|=2;
      }
      if (flag == 3)
      {
	my_error(ER_MIX_OF_GROUP_FUNC_AND_FIELDS,MYF(0));
	DBUG_RETURN(-1);
      }
    }
    TABLE_LIST *table;
364 365
    for (table=tables_list ; table ; table=table->next)
      tables++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
366
  }
367 368 369 370 371 372 373
  {
    /* Caclulate the number of groups */
    send_group_parts= 0;
    for (ORDER *group= group_list ; group ; group= group->next)
      send_group_parts++;
  }
  
374
  procedure= setup_procedure(thd, proc_param, result, fields_list, &error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
375
  if (error)
376
    goto err;					/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
377 378
  if (procedure)
  {
379 380
    if (setup_new_fields(thd, tables_list, fields_list, all_fields,
			 procedure->param_fields))
381
	goto err;				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
382 383
    if (procedure->group)
    {
384
      if (!test_if_subpart(procedure->group,group_list))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
385 386 387
      {						/* purecov: inspected */
	my_message(0,"Can't handle procedures with differents groups yet",
		   MYF(0));			/* purecov: inspected */
388
	goto err;				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
389 390 391
      }
    }
#ifdef NOT_NEEDED
392
    else if (!group_list && procedure->flags & PROC_GROUP)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
393 394
    {
      my_message(0,"Select must have a group with this procedure",MYF(0));
395
      goto err;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
396 397 398
    }
#endif
    if (order && (procedure->flags & PROC_NO_SORT))
399
    {						/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
400
      my_message(0,"Can't use order with this procedure",MYF(0)); /* purecov: inspected */
401
      goto err;					/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
402 403 404 405
    }
  }

  /* Init join struct */
406
  count_field_types(&tmp_table_param, all_fields, 0);
407
  ref_pointer_array_size= all_fields.elements*sizeof(Item*);
408 409 410
  this->group= group_list != 0;
  row_limit= ((select_distinct || order || group_list) ? HA_POS_ERROR :
	      unit->select_limit_cnt);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
411 412 413 414
  /* select_limit is used to decide if we are likely to scan the whole table */
  select_limit= unit->select_limit_cnt;
  if (having || (select_options & OPTION_FOUND_ROWS))
    select_limit= HA_POS_ERROR;
415
  do_send_rows = (unit->select_limit_cnt) ? 1 : 0;
416
  this->unit= unit;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
417 418

#ifdef RESTRICTED_GROUP
419
  if (sum_func_count && !group_list && (func_count || field_count))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
420
  {
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
421
    my_message(ER_WRONG_SUM_SELECT,ER(ER_WRONG_SUM_SELECT),MYF(0));
422
    goto err;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
423 424
  }
#endif
425
  if (!procedure && result->prepare(fields_list, unit))
426 427 428 429 430 431 432
    goto err;					/* purecov: inspected */

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

433
  DBUG_RETURN(0); // All OK
434 435 436 437 438

err:
  delete procedure;				/* purecov: inspected */
  procedure= 0;
  DBUG_RETURN(-1);				/* purecov: inspected */
439
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
440

441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
/*
  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 &&
457
      ((Item_func *)this->conds)->functype() == Item_func::EQ_FUNC &&
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476
      ((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)
  {
    *where= conds;
    join_tab->info= "Using index; Using where";
    return 1;
  }
  return 0;
}


477 478 479 480 481 482 483 484 485 486 487
/*
  global select optimisation.
  return 0 - success
         1 - go out
        -1 - go out with cleaning
  error code saved in field 'error'
*/
int
JOIN::optimize()
{
  DBUG_ENTER("JOIN::optimize");
488
  // to prevent double initialization on EXPLAIN
489 490 491
  if (optimized)
    DBUG_RETURN(0);
  optimized= 1;
492

493 494 495
  // Ignore errors of execution if option IGNORE present
  if (thd->lex.duplicates == DUP_IGNORE)
    thd->lex.current_select->no_error= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
496 497
#ifdef HAVE_REF_TO_FIELDS			// Not done yet
  /* Add HAVING to WHERE if possible */
498
  if (having && !group_list && !sum_func_count)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
499 500 501
  {
    if (!conds)
    {
502 503
      conds= having;
      having= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
504 505 506
    }
    else if ((conds=new Item_cond_and(conds,having)))
    {
507
      conds->fix_fields(thd, tables_list, &conds);
508
      conds->change_ref_to_fields(thd, tables_list);
509
      conds->top_level_item();
510
      having= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
511 512 513 514
    }
  }
#endif

515
  conds= optimize_cond(conds,&cond_value);
516
  if (thd->net.report_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
517
  {
518
    // quick abort
bk@work.mysql.com's avatar
bk@work.mysql.com committed
519
    delete procedure;
520
    error= thd->is_fatal_error ? -1 : 1; 
521
    DBUG_PRINT("error",("Error from optimize_cond"));
522
    DBUG_RETURN(error);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
523
  }
524

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
525 526
  if (cond_value == Item::COND_FALSE ||
      (!unit->select_limit_cnt && !(select_options & OPTION_FOUND_ROWS)))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
527
  {						/* Impossible cond */
528
    zero_result_cause= "Impossible WHERE";
529
    error= 0;
530
    DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
531 532 533
  }

  /* Optimize count(*), min() and max() */
534
  if (tables_list && tmp_table_param.sum_func_count && ! group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
535 536
  {
    int res;
537
    /*
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
538 539
      opt_sum_query() returns -1 if no rows match to the WHERE conditions,
      or 1 if all items were resolved, or 0, or an error number HA_ERR_...
540
    */
541
    if ((res=opt_sum_query(tables_list, all_fields, conds)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
542
    {
543 544 545 546 547
      if (res > 1)
      {
	delete procedure;
	DBUG_RETURN(-1);
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
548 549
      if (res < 0)
      {
550
	zero_result_cause= "No matching min/max row";
551
	error=0; 
552
	DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
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
bk@work.mysql.com's avatar
bk@work.mysql.com committed
556 557
    }
  }
558
  if (!tables_list)
559 560
  {
    error= 0;
561
    DBUG_RETURN(0);
562
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
563
  error= -1;					// Error is sent to client
564
  sort_by_table= get_sort_by_table(order, group_list, tables_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
565 566

  /* Calculate how to do the join */
567 568
  thd->proc_info= "statistics";
  if (make_join_statistics(this, tables_list, conds, &keyuse) ||
569
      thd->is_fatal_error)
570 571
  {
    DBUG_PRINT("error",("Error: make_join_statistics() failed"));
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
572
    DBUG_RETURN(1);
573
  }
574

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
575 576
  /* Remove distinct if only const tables */
  select_distinct= select_distinct && (const_tables != tables);
577
  thd->proc_info= "preparing";
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
578
  if (result->initialize_tables(this))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
579
  {
580 581
    DBUG_PRINT("error",("Error: initialize_tables() failed"));
    DBUG_RETURN(1);				// error == -1
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
582
  }
583
  if (const_table_map != found_const_table_map &&
584
      !(select_options & SELECT_DESCRIBE))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
585
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
586
    zero_result_cause= "no matching row in const table";
587
    DBUG_PRINT("error",("Error: %s", zero_result_cause));
588
    select_options= 0; //TODO why option in return_zero_rows was droped
589
    error= 0;
590
    DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
591 592
  }
  if (!(thd->options & OPTION_BIG_SELECTS) &&
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
593
      best_read > (double) thd->variables.max_join_size &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
594 595
      !(select_options & SELECT_DESCRIBE))
  {						/* purecov: inspected */
596
    my_message(ER_TOO_BIG_SELECT, ER(ER_TOO_BIG_SELECT), MYF(0));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
597
    error= 1;					/* purecov: inspected */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
598
    DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
599
  }
600
  if (const_tables && !thd->locked_tables &&
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
601
      !(select_options & SELECT_NO_UNLOCK))
602 603
  {
    TABLE **table, **end;
604
    for (table=this->table, end=table + const_tables ;
605 606 607 608 609 610 611 612 613 614 615
	 table != end;
	 table++)
    {
      /* BDB tables require that we call index_end() before doing an unlock */
      if ((*table)->key_read)
      {
	(*table)->key_read=0;
	(*table)->file->extra(HA_EXTRA_NO_KEYREAD);
      }
      (*table)->file->index_end();
    }
616
    mysql_unlock_some_tables(thd, this->table, const_tables);
617
  }
618
  if (!conds && outer_join)
619 620 621 622
  {
    /* Handle the case where we have an OUTER JOIN without a WHERE */
    conds=new Item_int((longlong) 1,1);	// Always true
  }
623 624
  select=make_select(*table, const_table_map,
		     const_table_map, conds, &error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
625
  if (error)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
626 627
  {						/* purecov: inspected */
    error= -1;					/* purecov: inspected */
628
    DBUG_PRINT("error",("Error: make_select() failed"));
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
629
    DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
630
  }
631
  if (make_join_select(this, select, conds))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
632
  {
633 634
    zero_result_cause=
      "Impossible WHERE noticed after reading const tables";
635
    DBUG_RETURN(0);				// error == 0
bk@work.mysql.com's avatar
bk@work.mysql.com committed
636 637 638 639 640
  }

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

  /* Optimize distinct away if possible */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
641 642
  {
    ORDER *org_order= order;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
643
    order=remove_const(this, order,conds,&simple_order);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
644 645 646 647 648 649 650
    /*
      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;
  }
651 652
  order= remove_const(this, order, conds, &simple_order);
  if (group_list || tmp_table_param.sum_func_count)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
653 654 655 656
  {
    if (! hidden_group_fields)
      select_distinct=0;
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
657
  else if (select_distinct && tables - const_tables == 1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
658
  {
659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
    /*
      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
674
    JOIN_TAB *tab= &join_tab[const_tables];
675 676 677
    bool all_order_fields_used;
    if (order)
      skip_sort_order= test_if_skip_sort_order(tab, order, select_limit, 1);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
678 679
    if ((group_list=create_distinct_group(thd, order, fields_list,
				          &all_order_fields_used)))
680 681
    {
      bool skip_group= (skip_sort_order &&
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
682
			test_if_skip_sort_order(tab, group_list, select_limit,
683 684 685 686 687 688 689 690 691
						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)
692 693 694 695 696 697 698
	{
	  if (order && skip_sort_order)
	  {
	    /*
	      Force MySQL to read the table in sorted order to get result in
	      ORDER BY order.
	    */	    
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
699
	    tmp_table_param.quick_group=0;
700
	  }
701
	  order=0;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
702
        }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
703
	group=1;				// For end_write_group
704 705
      }
      else
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
706
	group_list= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
707
    }
708
    else if (thd->is_fatal_error)			// End of memory
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
709
      DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
710
  }
711 712 713
  simple_group= 0;
  if (rollup.state == ROLLUP::STATE_NONE)
    group_list= remove_const(this, group_list, conds, &simple_group);
714
  if (!group_list && group)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
715 716 717 718 719
  {
    order=0;					// The output has only one row
    simple_order=1;
  }

720 721
  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
722 723
  if (procedure && procedure->group)
  {
724 725 726
    group_list= procedure->group= remove_const(this, procedure->group, conds,
					       &simple_group);
    calc_group_buffer(this, group_list);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
727 728
  }

729 730
  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
731 732
    order=0;

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
733
  // Can't use sort on head table if using row cache
734
  if (full_join)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
735
  {
736
    if (group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
737 738 739 740 741
      simple_group=0;
    if (order)
      simple_order=0;
  }

742 743 744 745 746 747 748 749 750
  /*
    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.
  */
751
  need_tmp= (const_tables != tables &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
752
	     ((select_distinct || !simple_order || !simple_group) ||
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
753
	      (group_list && order) ||
754
	      test(select_options & OPTION_BUFFER_RESULT)));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
755

756
  // No cache for MATCH
757
  make_join_readinfo(this,
758
		     (select_options & (SELECT_DESCRIBE |
759
					SELECT_NO_JOIN_CACHE)) |
760
		     (select_lex->ftfunc_list->elements ? 
761
		      SELECT_NO_JOIN_CACHE : 0));
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
762

763 764 765
  /*
    is this simple IN subquery?
  */
766
  if (!group_list && !order &&
767
      unit->item && unit->item->substype() == Item_subselect::IN_SUBS &&
768
      tables == 1 && conds &&
769 770
      !unit->first_select()->next_select())
  {
771
    if (!having)
772
    {
773
      Item *where= 0;
774 775
      if (join_tab[0].type == JT_EQ_REF &&
	  join_tab[0].ref.items[0]->name == in_left_expr_name)
776
      {
777 778 779 780 781 782 783 784 785 786
	if (test_in_subselect(&where))
	{
	  join_tab[0].type= JT_SIMPLE_IN;
	  error= 0;
	  DBUG_RETURN(unit->item->
		      change_engine(new subselect_simplein_engine(thd,
								  join_tab,
								  unit->item,
								  where)));
	}
787
      }
788 789
      else if (join_tab[0].type == JT_REF &&
	       join_tab[0].ref.items[0]->name == in_left_expr_name)
790
      {
791 792 793 794 795 796 797 798 799 800 801
	if (test_in_subselect(&where))
	{
	  join_tab[0].type= JT_INDEX_IN;
	  error= 0;
	  DBUG_RETURN(unit->item->
		      change_engine(new subselect_indexin_engine(thd,
								 join_tab,
								 unit->item,
								 where,
								 0)));
	}
802
      }
803
    } else if (join_tab[0].type == JT_REF_OR_NULL &&
804
	       join_tab[0].ref.items[0]->name == in_left_expr_name &&
805 806 807 808 809 810 811 812 813 814 815 816
	       having->type() == Item::FUNC_ITEM &&
	       ((Item_func *) having)->functype() ==
	       Item_func::ISNOTNULLTEST_FUNC)
    {
      join_tab[0].type= JT_INDEX_IN;
      error= 0;
      DBUG_RETURN(unit->item->
		  change_engine(new subselect_indexin_engine(thd,
							     join_tab,
							     unit->item,
							     conds,
							     1)));
817
    }
818
	       
819
  }
820 821 822 823 824 825 826
  /*
    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
827 828

#ifdef HAVE_INNOBASE_DB
829
  if (need_tmp || select_distinct || group_list || order)
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
830
  {
831
    for (uint i_h = const_tables; i_h < tables; i_h++)
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
832
    {
833
      TABLE* table_h = join_tab[i_h].table;
834
      if (table_h->db_type == DB_TYPE_INNODB)
835
	table_h->file->extra(HA_EXTRA_DONT_USE_CURSOR_TO_UPDATE);
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
836 837 838 839
    }
  }
#endif

840
  DBUG_EXECUTE("info",TEST_join(this););
bk@work.mysql.com's avatar
bk@work.mysql.com committed
841 842 843 844 845
  /*
    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.
846
  */
847 848 849
  if ((order || group_list) && join_tab[const_tables].type != JT_ALL &&
      join_tab[const_tables].type != JT_FT &&
      (order && simple_order || group_list && simple_group))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
850
  {
851
    if (add_ref_to_table_cond(thd,&join_tab[const_tables]))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
852
      DBUG_RETURN(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
853 854 855
  }

  if (!(select_options & SELECT_BIG_RESULT) &&
856
      ((group_list && const_tables != tables &&
857
	(!simple_group ||
858 859 860
	 !test_if_skip_sort_order(&join_tab[const_tables], group_list,
				  unit->select_limit_cnt,
				  0))) ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
861
       select_distinct) &&
862
      tmp_table_param.quick_group && !procedure)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
863 864 865
  {
    need_tmp=1; simple_order=simple_group=0;	// Force tmp table without sort
  }
866 867

  if (select_options & SELECT_DESCRIBE)
868 869
  {
    error= 0;
870
    DBUG_RETURN(0);
871
  }
872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895
  tmp_having= having;
  having= 0;

  /* Perform FULLTEXT search before all regular searches */
  init_ftfuncs(thd, select_lex, test(order));
  /* 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();
    
    tmp_table_param.hidden_field_count= (all_fields.elements -
					 fields_list.elements);
    if (!(exec_tmp_table1 =
	  create_tmp_table(thd, &tmp_table_param, all_fields,
			   ((!simple_group && !procedure &&
			     !(test_flags & TEST_NO_KEY_GROUP)) ?
			    group_list : (ORDER*) 0),
			   group_list ? 0 : select_distinct,
			   group_list && simple_group,
			   select_options,
			   (order == 0 || skip_sort_order) ? select_limit :
896 897
			   HA_POS_ERROR,
			   (char *) "")))
898
      DBUG_RETURN(1);
899 900 901 902 903 904 905 906 907 908 909

    /*
      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.
    */    
910 911 912 913 914 915 916 917 918 919 920
    if (having && 
	(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";
      if (create_sort_index(thd, &join_tab[const_tables], group_list,
			    HA_POS_ERROR, HA_POS_ERROR) ||
921 922
	  alloc_group_fields(this, group_list) ||
	  make_sum_func_list(all_fields, fields_list, 1))
923 924 925 926 927
	DBUG_RETURN(1);
      group_list=0;
    }
    else
    {
928
      if (make_sum_func_list(all_fields, fields_list, 0))
929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
	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";
	if (create_sort_index(thd, &join_tab[const_tables], order,
                              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;
      JOIN_TAB *join_tab= this->join_tab+tables-1;
      do
      {
	if (used_tables & join_tab->table->map)
	  break;
	join_tab->not_used_in_distinct=1;
      } while (join_tab-- != this->join_tab);
      /* Optimize "select distinct b from t1 order by key_part_1 limit #" */
      if (order && skip_sort_order)
      {
 	/* Should always succeed */
	if (test_if_skip_sort_order(&this->join_tab[const_tables],
				    order, unit->select_limit_cnt, 0))
	  order=0;
      }
    }
    
    if (select_lex != &thd->lex.select_lex &&
	select_lex->linkage != DERIVED_TABLE_TYPE)
    {
      if (!(tmp_join= (JOIN*)thd->alloc(sizeof(JOIN))))
	DBUG_RETURN(-1);
972
      error= 0;				// Ensure that tmp_join.error= 0
973 974 975 976
      restore_tmp();
    }
  }

977
  error= 0;
978 979 980 981
  DBUG_RETURN(0);
}

/*
982
  Restore values in temporary join
983 984
*/

985
void JOIN::restore_tmp()
986
{
987
  memcpy(tmp_join, this, (size_t) sizeof(JOIN));
988 989
}

990

991 992 993 994
int
JOIN::reinit()
{
  DBUG_ENTER("JOIN::reinit");
995
  /* TODO move to unit reinit */
996 997 998 999 1000 1001
  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
1002
  
1003 1004
  if (setup_tables(tables_list))
    DBUG_RETURN(1);
1005
  
1006
  /* Reset of sum functions */
1007 1008 1009 1010 1011 1012 1013
  first_record= 0;
  if (sum_funcs)
  {
    Item_sum *func, **func_ptr= sum_funcs;
    while ((func= *(func_ptr++)))
      func->null_value= 1;
  }
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1014

1015 1016 1017 1018 1019
  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);
1020
    filesort_free_buffers(exec_tmp_table1);
1021 1022 1023 1024 1025 1026
  }
  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);
1027
    filesort_free_buffers(exec_tmp_table2);
1028 1029
  }
  if (items0)
1030
    set_items_ref_array(items0);
1031 1032 1033 1034

  if (tmp_join)
    restore_tmp();

1035 1036 1037
  DBUG_RETURN(0);
}

1038
/*
1039
  Exec select
1040 1041 1042 1043 1044 1045
*/
void
JOIN::exec()
{
  int      tmp_error;
  DBUG_ENTER("JOIN::exec");
1046
  
1047
  error= 0;
1048 1049 1050 1051 1052 1053
  if (procedure)
  {
    if (procedure->change_columns(fields_list) ||
	result->prepare(fields_list, unit))
      DBUG_VOID_RETURN;
  }
1054

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1055
  if (!tables_list)
1056 1057
  {                                           // Only test of functions
    if (select_options & SELECT_DESCRIBE)
1058 1059
      select_describe(this, false, false, false,
		      (zero_result_cause?zero_result_cause:"No tables used"));
1060 1061 1062 1063 1064
    else
    {
      result->send_fields(fields_list,1);
      if (!having || having->val_int())
      {
1065 1066 1067
	if (do_send_rows && (procedure ? (procedure->send_row(fields_list) ||
                                          procedure->end_of_records())
                                       : result->send_data(fields_list)))
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1068
	  error= 1;
1069
	else
1070
	{
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1071
	  error= (int) result->send_eof();
1072 1073
	  send_records=1;
	}
1074 1075
      }
      else
1076
	error=(int) result->send_eof();
1077 1078 1079 1080 1081 1082
    }
    DBUG_VOID_RETURN;
  }

  if (zero_result_cause)
  {
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1083 1084 1085 1086 1087
    (void) return_zero_rows(this, result, tables_list, fields_list,
			    tmp_table_param.sum_func_count != 0 &&
			    !group_list,
			    select_options,
			    zero_result_cause,
1088
			    having, procedure,
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
1089
			    unit);
1090 1091 1092
    DBUG_VOID_RETURN;
  }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1093 1094 1095
  if (select_options & SELECT_DESCRIBE)
  {
    if (!order && !no_order)
1096
      order=group_list;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1097
    if (order &&
1098
	(const_tables == tables ||
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1099
 	 ((simple_order || skip_sort_order) &&
1100
	  test_if_skip_sort_order(&join_tab[const_tables], order,
1101
				  select_limit, 0))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1102
      order=0;
1103
    having= tmp_having;
1104
    select_describe(this, need_tmp,
1105
		    order != 0 && !skip_sort_order,
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
1106
		    select_distinct);
1107
    DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1108 1109
  }

1110 1111 1112 1113
  JOIN *curr_join= this;
  List<Item> *curr_all_fields= &all_fields;
  List<Item> *curr_fields_list= &fields_list;
  TABLE *curr_tmp_table= 0;
1114

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1115 1116 1117
  /* Create a tmp table if distinct or if the sort is too complicated */
  if (need_tmp)
  {
1118 1119 1120
    if (tmp_join)
      curr_join= tmp_join;
    curr_tmp_table= exec_tmp_table1;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
1121 1122

    /* Copy data to the temporary table */
1123
    thd->proc_info= "Copying to tmp table";
1124 1125
    
    if ((tmp_error= do_select(curr_join, (List<Item> *) 0, curr_tmp_table, 0)))
1126
    {
1127 1128
      error= tmp_error;
      DBUG_VOID_RETURN;
1129
    }
1130 1131 1132 1133 1134
    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
1135
    /* Change sum_fields reference to calculated fields in tmp_table */
1136 1137
    curr_join->all_fields= *curr_all_fields;
    if (!items1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1138
    {
1139 1140 1141
      items1= items0 + all_fields.elements;
      if (sort_and_group || curr_tmp_table->group)
      {
1142
	if (change_to_use_tmp_fields(thd, items1,
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
				     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;
1160
    set_items_ref_array(items1);
1161 1162 1163 1164 1165 1166 1167 1168
    
    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
1169 1170 1171
    }
    else
    {
1172 1173 1174
      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
1175
    }
1176 1177
    
    // procedure can't be used inside subselect => we do nothing special for it
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1178 1179
    if (procedure)
      procedure->update_refs();
1180 1181
    
    if (curr_tmp_table->group)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1182
    {						// Already grouped
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1183
      if (!curr_join->order && !curr_join->no_order && !skip_sort_order)
1184 1185
	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
1186
    }
1187
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1188
    /*
1189 1190 1191 1192 1193
      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
1194 1195
    */

1196 1197 1198 1199 1200
    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
1201 1202
    {					/* Must copy to another table */
      DBUG_PRINT("info",("Creating group table"));
1203
      
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1204
      /* Free first data from old join */
1205 1206
      join_free(curr_join, 0);
      if (make_simple_join(curr_join, curr_tmp_table))
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1207
	DBUG_VOID_RETURN;
1208
      calc_group_buffer(curr_join, group_list);
1209 1210
      count_field_types(&curr_join->tmp_table_param,
			curr_join->tmp_all_fields1,
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
			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,
1230 1231
						HA_POS_ERROR,
						(char *) "")))
1232 1233 1234
	  DBUG_VOID_RETURN;
	curr_join->exec_tmp_table2= exec_tmp_table2;
      }
1235
      if (curr_join->group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1236
      {
1237 1238 1239
	thd->proc_info= "Creating sort index";
	if (create_sort_index(thd, curr_join->join_tab, curr_join->group_list,
			      HA_POS_ERROR, HA_POS_ERROR) ||
1240
	    make_group_fields(this, curr_join))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1241
	{
1242
	  DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1243
	}
1244
	curr_join->group_list= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1245
      }
1246
      
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1247
      thd->proc_info="Copying to group table";
1248
      tmp_error= -1;
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
      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;
	}
      }
1263 1264
      if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
					1) ||
1265 1266
	  (tmp_error= do_select(curr_join, (List<Item> *) 0, curr_tmp_table,
				0)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1267
      {
1268
	error= tmp_error;
1269
	DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1270
      }
1271 1272 1273 1274 1275 1276 1277 1278
      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;
1279
	if (change_to_use_tmp_fields(thd, items2,
1280 1281 1282 1283 1284 1285 1286 1287
				     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;
1288
      set_items_ref_array(items2);
1289 1290 1291 1292 1293 1294 1295 1296
      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 */
    
    join_free(curr_join, 0);			/* Free quick selects */
1297
    if (select_distinct && ! group_list)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1298 1299
    {
      thd->proc_info="Removing duplicates";
1300 1301 1302 1303
      if (curr_join->tmp_having)
	curr_join->tmp_having->update_used_tables();
      if (remove_duplicates(curr_join, curr_tmp_table,
			    curr_join->fields_list, curr_join->tmp_having))
1304
	DBUG_VOID_RETURN;
1305 1306
      curr_join->tmp_having=0;
      curr_join->select_distinct=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1307
    }
1308 1309
    curr_tmp_table->reginfo.lock_type= TL_UNLOCK;
    if (make_simple_join(curr_join, curr_tmp_table))
1310
      DBUG_VOID_RETURN;
1311 1312 1313
    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
1314 1315
  }
  if (procedure)
1316 1317 1318
    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
1319 1320
      (procedure && (procedure->flags & PROC_GROUP)))
  {
1321 1322 1323 1324
    if (make_group_fields(this, curr_join))
    {
      DBUG_VOID_RETURN;
    }
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348
    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;
1349
    set_items_ref_array(items3);
1350

1351 1352
    if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
				      1) || thd->is_fatal_error)
1353
      DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1354
  }
1355
  if (curr_join->group_list || curr_join->order)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1356 1357 1358 1359
  {
    DBUG_PRINT("info",("Sorting for send_fields"));
    thd->proc_info="Sorting result";
    /* If we have already done the group, add HAVING to sorted table */
1360 1361
    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
1362
    {
1363 1364
      // Some tables may have been const
      curr_join->tmp_having->update_used_tables();
1365
      JOIN_TAB *table= &curr_join->join_tab[curr_join->const_tables];
1366
      table_map used_tables= curr_join->const_table_map | table->table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1367

1368 1369
      Item* sort_table_cond= make_cond_for_table(curr_join->tmp_having,
						 used_tables,
1370
						 used_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1371 1372 1373
      if (sort_table_cond)
      {
	if (!table->select)
1374
	  if (!(table->select= new SQL_SELECT))
1375
	    DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1376
	if (!table->select->cond)
1377
	  table->select->cond= sort_table_cond;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1378
	else					// This should never happen
1379 1380
	  if (!(table->select->cond= new Item_cond_and(table->select->cond,
						       sort_table_cond)))
1381
	    DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1382
	table->select_cond=table->select->cond;
1383
	table->select_cond->top_level_item();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1384 1385
	DBUG_EXECUTE("where",print_where(table->select->cond,
					 "select and having"););
1386 1387 1388
	curr_join->tmp_having= make_cond_for_table(curr_join->tmp_having,
						   ~ (table_map) 0,
						   ~used_tables);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1389 1390 1391
	DBUG_EXECUTE("where",print_where(conds,"having after sort"););
      }
    }
1392
    {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1393
      if (group)
1394
	curr_join->select_limit= HA_POS_ERROR;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1395
      else
1396
      {
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1397 1398 1399 1400
	/*
	  We can abort sorting after thd->select_limit rows if we there is no
	  WHERE clause for any tables after the sorted one.
	*/
1401
	JOIN_TAB *table= &curr_join->join_tab[curr_join->const_tables+1];
1402
	JOIN_TAB *end_table= &curr_join->join_tab[tables];
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1403
	for (; table < end_table ; table++)
1404
	{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1405 1406 1407 1408 1409 1410 1411
	  /*
	    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.
	  */
	  if (table->select_cond || (table->keyuse && !table->on_expr))
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1412 1413
	  {
	    /* We have to sort all rows */
1414
	    curr_join->select_limit= HA_POS_ERROR;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
1415 1416
	    break;
	  }
1417 1418
	}
      }
1419 1420 1421 1422 1423
      if (create_sort_index(thd, &curr_join->join_tab[curr_join->const_tables],
			    curr_join->group_list ? 
			    curr_join->group_list : curr_join->order,
			    curr_join->select_limit, unit->select_limit_cnt))
	DBUG_VOID_RETURN;
1424
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1425
  }
1426
  curr_join->having= curr_join->tmp_having;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1427
  thd->proc_info="Sending data";
1428
  error= thd->net.report_error ||
1429
    do_select(curr_join, curr_fields_list, NULL, procedure);
1430 1431
  DBUG_VOID_RETURN;
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1432

1433

1434 1435 1436 1437 1438
/*
  Clean up join. Return error that hold JOIN.
*/

int
1439
JOIN::cleanup()
1440
{
1441
  DBUG_ENTER("JOIN::cleanup");
1442 1443 1444
  select_lex->join= 0;

  if (tmp_join)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1445 1446 1447 1448 1449 1450
  {
    if (join_tab != tmp_join->join_tab)
    {
      JOIN_TAB *tab, *end;
      for (tab= join_tab, end= tab+tables ; tab != end ; tab++)
      {
1451 1452 1453 1454
	delete tab->select;
	delete tab->quick;
	tab->select=0;
	tab->quick=0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1455
	x_free(tab->cache.buff);
1456
	tab->cache.buff= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1457 1458 1459
      }
    }
    tmp_join->tmp_join= 0;
1460
    DBUG_RETURN(tmp_join->cleanup());
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1461
  }
1462

1463
  lock=0;                                     // It's faster to unlock later
1464
  join_free(this, 1);
1465 1466 1467 1468
   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
1469 1470 1471
  delete select;
  delete_dynamic(&keyuse);
  delete procedure;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
1472 1473 1474
  for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit();
       unit != 0;
       unit= unit->next_unit())
1475
  {
1476
    error|= unit->cleanup();
1477 1478
  }
  DBUG_RETURN(error);
1479 1480
}

1481

1482
int
1483 1484 1485 1486 1487
mysql_select(THD *thd, Item ***rref_pointer_array,
	     TABLE_LIST *tables, uint wild_num, List<Item> &fields, 
	     COND *conds, uint og_num,  ORDER *order, ORDER *group,
	     Item *having, ORDER *proc_param, ulong select_options,
	     select_result *result, SELECT_LEX_UNIT *unit,
1488
	     SELECT_LEX *select_lex,  bool tables_and_fields_initied)
1489
{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1490 1491
  int err;
  bool free_join= 1;
1492 1493
  DBUG_ENTER("mysql_select");

1494
  JOIN *join;
1495
  if (select_lex->join != 0)
1496
  {
1497
    join= select_lex->join;
1498
    if (select_lex->linkage != GLOBAL_OPTIONS_TYPE)
1499
    {
1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514
      //here is EXPLAIN of subselect or derived table
      join->result= result;
      if (!join->procedure && result->prepare(join->fields_list, unit))
      {
	DBUG_RETURN(-1);
      }
    }
    else
    {
      if (join->prepare(rref_pointer_array, tables, wild_num,
			conds, og_num, order, group, having, proc_param,
			select_lex, unit, tables_and_fields_initied))
      {
	DBUG_RETURN(-1);
      }
1515 1516 1517
    }
    join->select_options= select_options;
    free_join= 0;
1518
  }
1519 1520 1521 1522 1523
  else
  {
    join= new JOIN(thd, fields, select_options, result);
    thd->proc_info="init";
    thd->used_tables=0;                         // Updated by setup_fields
1524 1525
    if (join->prepare(rref_pointer_array, tables, wild_num,
		      conds, og_num, order, group, having, proc_param,
1526
		      select_lex, unit, tables_and_fields_initied))
1527 1528 1529 1530 1531
    {
      DBUG_RETURN(-1);
    }
  }

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1532
  if ((err= join->optimize()))
1533
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1534 1535 1536 1537 1538
    if (err == -1)
      DBUG_RETURN(join->error);
    DBUG_ASSERT(err == 1);
    goto err;					// 1
  }
1539

1540
  if (thd->net.report_error)
1541 1542 1543 1544 1545
    goto err;

  join->exec();

err:
1546 1547
  if (free_join)
  {
1548 1549 1550 1551 1552 1553
    JOIN *curr_join= (join->need_tmp&&join->tmp_join?
		      (join->tmp_join->error=join->error,join->tmp_join):
		      join);
    
    thd->limit_found_rows= curr_join->send_records;
    thd->examined_row_count= curr_join->examined_rows;
1554
    thd->proc_info="end";
1555
    err= join->cleanup();
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1556 1557
    if (thd->net.report_error)
      err= -1;
1558
    delete join;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1559
    DBUG_RETURN(err);
1560
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
1561
  DBUG_RETURN(join->error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1562 1563 1564
}

/*****************************************************************************
1565 1566
  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
1567 1568 1569
*****************************************************************************/

static ha_rows get_quick_record_count(SQL_SELECT *select,TABLE *table,
1570
				      key_map keys,ha_rows limit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1571 1572 1573 1574 1575 1576 1577
{
  int error;
  DBUG_ENTER("get_quick_record_count");
  if (select)
  {
    select->head=table;
    table->reginfo.impossible_range=0;
1578
    if ((error=select->test_quick_select(keys,(table_map) 0,limit))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591
	== 1)
      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 */
}


1592 1593 1594 1595 1596 1597 1598
/*
  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
1599

bk@work.mysql.com's avatar
bk@work.mysql.com committed
1600 1601
static bool
make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
1602
		     DYNAMIC_ARRAY *keyuse_array)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1603 1604
{
  int error;
1605 1606 1607
  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
1608 1609 1610 1611 1612 1613 1614 1615
  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;
1616 1617
  stat=(JOIN_TAB*) join->thd->calloc(sizeof(JOIN_TAB)*table_count);
  stat_ref=(JOIN_TAB**) join->thd->alloc(sizeof(JOIN_TAB*)*MAX_TABLES);
1618
  table_vector=(TABLE**) join->thd->alloc(sizeof(TABLE*)*(table_count*2));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1619 1620 1621 1622 1623 1624
  if (!stat || !stat_ref || !table_vector)
    DBUG_RETURN(1);				// Eom /* purecov: inspected */

  join->best_ref=stat_vector;

  stat_end=stat+table_count;
1625
  found_const_table_map= all_table_map=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638
  const_count=0;

  for (s=stat,i=0 ; tables ; s++,tables=tables->next,i++)
  {
    TABLE *table;
    stat_vector[i]=s;
    table_vector[i]=s->table=table=tables->table;
    table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);// record count
    table->quick_keys=0;
    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;
1639
    s->join=join;
1640
    s->info=0;					// For describe
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1641 1642
    if ((s->on_expr=tables->on_expr))
    {
1643
      /* Left join */
1644 1645
      if (!table->file->records)
      {						// Empty table
1646
	s->key_dependent=s->dependent=0;	// Ignore LEFT JOIN depend.
1647 1648 1649
	set_position(join,const_count++,s,(KEYUSE*) 0);
	continue;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1650 1651
      s->key_dependent=s->dependent=
	s->on_expr->used_tables() & ~(table->map);
1652 1653 1654 1655
      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
1656 1657 1658 1659 1660 1661 1662 1663
      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;
1664
    if ((table->system || table->file->records <= 1) && ! s->dependent &&
1665
	!(table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
1666
        !table->fulltext_searched)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1667 1668 1669 1670 1671
    {
      set_position(join,const_count++,s,(KEYUSE*) 0);
    }
  }
  stat_vector[i]=0;
1672
  join->outer_join=outer_join;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1673 1674

  /*
1675 1676 1677 1678
    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
1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
  */
  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)
1711 1712
    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
1713 1714
      DBUG_RETURN(1);

1715
  /* Read tables with 0 or 1 rows (system tables) */
1716
  join->const_table_map= 0;
1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734

  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
1735
  /* loop until no more const tables are found */
1736
  int ref_changed;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1737 1738
  do
  {
1739
    ref_changed = 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1740
    found_ref=0;
1741 1742 1743 1744 1745 1746 1747

    /*
      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
1748
    {
1749
      TABLE *table=s->table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1750 1751
      if (s->dependent)				// If dependent on some table
      {
1752
	// All dep. must be constants
1753
	if (s->dependent & ~(found_const_table_map))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1754
	  continue;
1755
	if (table->file->records <= 1L &&
1756
	    !(table->file->table_flags() & HA_NOT_EXACT_COUNT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1757
	{					// system table
1758
	  int tmp= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1759
	  s->type=JT_SYSTEM;
1760
	  join->const_table_map|=table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1761
	  set_position(join,const_count++,s,(KEYUSE*) 0);
1762
	  if ((tmp= join_read_const_table(s,join->positions+const_count-1)))
1763 1764 1765 1766 1767 1768
	  {
	    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
1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
	  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;
	  s->keys|= (key_map) 1 << key;		// QQ: remove this ?

1782 1783
	  refs=const_ref=0;
	  eq_part=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1784 1785
	  do
	  {
1786
	    if (keyuse->val->type() != Item::NULL_ITEM && !keyuse->optimize)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1787
	    {
1788
	      if (!((~found_const_table_map) & keyuse->used_tables))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1789 1790 1791
		const_ref|= (key_map) 1 << keyuse->keypart;
	      else
		refs|=keyuse->used_tables;
1792
	      eq_part|= (key_map) 1 << keyuse->keypart;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1793 1794 1795 1796 1797
	    }
	    keyuse++;
	  } while (keyuse->table == table && keyuse->key == key);

	  if (eq_part == PREV_BITS(uint,table->key_info[key].key_parts) &&
1798 1799
	      (table->key_info[key].flags & HA_NOSAME) &&
              !table->fulltext_searched)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1800 1801 1802
	  {
	    if (const_ref == eq_part)
	    {					// Found everything for ref.
1803 1804
	      int tmp;
	      ref_changed = 1;
1805
	      s->type= JT_CONST;
1806
	      join->const_table_map|=table->map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1807
	      set_position(join,const_count++,s,start_keyuse);
1808
	      if (create_ref_for_key(join, s, start_keyuse,
1809
				     found_const_table_map))
1810 1811 1812 1813 1814 1815 1816 1817 1818
		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
1819 1820 1821 1822 1823 1824 1825 1826
	      break;
	    }
	    else
	      found_ref|= refs;		// Table is const if all refs are const
	  }
	}
      }
    }
1827
  } while (join->const_table_map & found_ref && ref_changed);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840

  /* 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;
1841
    s->read_time=(ha_rows) s->table->file->scan_time();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1842

1843 1844
    /*
      Set a max range of how many seeks we can expect when using keys
1845 1846
      This is can't be to high as otherwise we are likely to use
      table scan.
1847
    */
1848 1849
    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
1850 1851 1852 1853 1854 1855
    if (s->worst_seeks < 2.0)			// Fix for small tables
      s->worst_seeks=2.0;

    if (s->const_keys)
    {
      ha_rows records;
1856 1857 1858 1859 1860 1861 1862
      SQL_SELECT *select;
      select= make_select(s->table, found_const_table_map,
			  found_const_table_map,
			  s->on_expr ? s->on_expr : conds,
			  &error);
      records= get_quick_record_count(select,s->table, s->const_keys,
				      join->row_limit);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1863 1864 1865
      s->quick=select->quick;
      s->needed_reg=select->needed_reg;
      select->quick=0;
1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
      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
1886 1887
      if (records != HA_POS_ERROR)
      {
1888
	s->found_records=records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1889 1890
	s->read_time= (ha_rows) (s->quick ? s->quick->read_time : 0.0);
      }
1891
      delete select;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1892 1893 1894 1895 1896 1897 1898 1899
    }
  }

  /* 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;
1900
  join->found_const_table_map=found_const_table_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1901 1902

  if (join->const_tables != join->tables)
1903 1904
  {
    optimize_keyuse(join, keyuse_array);
1905
    find_best_combination(join,all_table_map & ~join->const_table_map);
1906
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1907 1908 1909 1910 1911 1912
  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
1913
  DBUG_RETURN(join->thd->killed || get_best_combination(join));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1914 1915 1916 1917
}


/*****************************************************************************
1918 1919 1920 1921 1922
  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
1923 1924 1925 1926 1927
*****************************************************************************/

typedef struct key_field_t {		// Used when finding key fields
  Field		*field;
  Item		*val;			// May be empty if diff constant
1928 1929
  uint		level;
  uint		optimize;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1930 1931 1932
  bool		eq_func;
} KEY_FIELD;

1933 1934 1935 1936 1937 1938 1939 1940
/* 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
1941

1942 1943 1944 1945 1946 1947
  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 
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1948 1949 1950 1951 1952 1953 1954 1955

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
1956
    return start;				// No new fields, skip all
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968

  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())
	{
1969 1970 1971 1972
	  /*
	    If the value matches, we can use the key reference.
	    If not, we keep it until we have examined all new values
	  */
1973
	  if (old->val->eq(new_fields->val, old->field->binary()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1974
	  {
1975 1976 1977 1978 1979
	    old->level= and_level;
	    old->optimize= ((old->optimize & new_fields->optimize &
			     KEY_OPTIMIZE_EXISTS) |
			    ((old->optimize | new_fields->optimize) &
			     KEY_OPTIMIZE_REF_OR_NULL));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1980 1981
	  }
	}
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993
	else if (old->eq_func && new_fields->eq_func &&
		 old->val->eq(new_fields->val, old->field->binary()))
		 
	{
	  old->level= and_level;
	  old->optimize= ((old->optimize & new_fields->optimize &
			   KEY_OPTIMIZE_EXISTS) |
			  ((old->optimize | new_fields->optimize) &
			   KEY_OPTIMIZE_REF_OR_NULL));
	}
	else if (old->eq_func && new_fields->eq_func &&
		 (old->val->is_null() || new_fields->val->is_null()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
1994
	{
1995 1996 1997 1998 1999 2000
	  /* field = expression OR field IS NULL */
	  old->level= and_level;
	  old->optimize= KEY_OPTIMIZE_REF_OR_NULL;
	  /* Remember the NOT NULL value */
	  if (old->val->is_null())
	    old->val= new_fields->val;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2001
	}
2002
	else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2003
	{
2004 2005 2006 2007 2008
	  /*
	    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
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
	  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 ;)
  {
2020
    if (old->level != and_level)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032
    {						// Not used in all levels
      if (old == --first_free)
	break;
      *old= *first_free;			// Remove old value
      continue;
    }
    old++;
  }
  return first_free;
}


2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053
/*
  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
				Is NULL for BETWEEN and IN    
    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
2054 2055 2056 2057 2058
static void
add_key_field(KEY_FIELD **key_fields,uint and_level,
	      Field *field,bool eq_func,Item *value,
	      table_map usable_tables)
{
2059
  uint exists_optimize= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2060 2061 2062 2063 2064
  if (!(field->flags & PART_KEY_FLAG))
  {
    // Don't remove column IS NULL on a LEFT JOIN table
    if (!eq_func || !value || value->type() != Item::NULL_ITEM ||
	!field->table->maybe_null || field->null_ptr)
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2065
      return;					// Not a key. Skip it
2066
    exists_optimize= KEY_OPTIMIZE_EXISTS;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2067 2068 2069 2070
  }
  else
  {
    table_map used_tables=0;
2071 2072
    if (value && ((used_tables=value->used_tables()) &
		  (field->table->map | RAND_TABLE_BIT)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2073 2074 2075 2076 2077 2078
      return;
    if (!(usable_tables & field->table->map))
    {
      if (!eq_func || !value || value->type() != Item::NULL_ITEM ||
	  !field->table->maybe_null || field->null_ptr)
	return;					// Can't use left join optimize
2079
      exists_optimize= KEY_OPTIMIZE_EXISTS;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2080 2081 2082 2083
    }
    else
    {
      JOIN_TAB *stat=field->table->reginfo.join_tab;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2084 2085 2086
      key_map possible_keys= (field->key_start &
			      field->table->keys_in_use_for_query);
      stat[0].keys|= possible_keys;		// Add possible keys
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2087 2088 2089

      if (!value)
      {						// Probably BETWEEN or IN
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2090
	stat[0].const_keys |= possible_keys;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2091 2092 2093
	return;					// Can't be used as eq key
      }

2094 2095 2096 2097 2098 2099 2100 2101
      /*
	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
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2102 2103 2104
      */
      stat[0].key_dependent|=used_tables;
      if (value->const_item())
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
2105
	stat[0].const_keys |= possible_keys;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2106

2107 2108 2109 2110
      /*
	We can't always use indexes when comparing a string index to a
	number. cmp_type() is checked to allow compare of dates to numbers
      */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2111 2112 2113 2114 2115 2116 2117 2118
      if (!eq_func ||
	  field->result_type() == STRING_RESULT &&
	  value->result_type() != STRING_RESULT &&
	  field->cmp_type() != value->result_type())
	return;
    }
  }
  /* Store possible eq field */
2119 2120 2121 2122 2123
  (*key_fields)->field=		field;
  (*key_fields)->eq_func=	eq_func;
  (*key_fields)->val=		value;
  (*key_fields)->level=		and_level;
  (*key_fields)->optimize=	exists_optimize;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
  (*key_fields)++;
}


static void
add_key_fields(JOIN_TAB *stat,KEY_FIELD **key_fields,uint *and_level,
	       COND *cond, table_map usable_tables)
{
  if (cond->type() == Item_func::COND_ITEM)
  {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
2134
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2135 2136 2137 2138 2139 2140 2141 2142
    KEY_FIELD *org_key_fields= *key_fields;

    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
      Item *item;
      while ((item=li++))
	add_key_fields(stat,key_fields,and_level,item,usable_tables);
      for (; org_key_fields != *key_fields ; org_key_fields++)
2143
	org_key_fields->level= *and_level;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
    }
    else
    {
      (*and_level)++;
      add_key_fields(stat,key_fields,and_level,li++,usable_tables);
      Item *item;
      while ((item=li++))
      {
	KEY_FIELD *start_key_fields= *key_fields;
	(*and_level)++;
	add_key_fields(stat,key_fields,and_level,item,usable_tables);
	*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:
2170
    if (cond_func->key_item()->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2171
	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2172
      add_key_field(key_fields,*and_level,
2173 2174
		    ((Item_field*) (cond_func->key_item()->real_item()))
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2175 2176 2177 2178 2179 2180 2181
		    0,(Item*) 0,usable_tables);
    break;
  case Item_func::OPTIMIZE_OP:
  {
    bool equal_func=(cond_func->functype() == Item_func::EQ_FUNC ||
		     cond_func->functype() == Item_func::EQUAL_FUNC);

2182
    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2183
	!(cond_func->arguments()[0]->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2184 2185
    {
      add_key_field(key_fields,*and_level,
2186 2187
		    ((Item_field*) (cond_func->arguments()[0])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2188 2189 2190
		    equal_func,
		    (cond_func->arguments()[1]),usable_tables);
    }
2191
    if (cond_func->arguments()[1]->real_item()->type() == Item::FIELD_ITEM &&
2192
	cond_func->functype() != Item_func::LIKE_FUNC &&
2193
	!(cond_func->arguments()[1]->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2194 2195
    {
      add_key_field(key_fields,*and_level,
2196 2197
		    ((Item_field*) (cond_func->arguments()[1])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2198 2199 2200 2201 2202 2203 2204
		    equal_func,
		    (cond_func->arguments()[0]),usable_tables);
    }
    break;
  }
  case Item_func::OPTIMIZE_NULL:
    /* column_name IS [NOT] NULL */
2205
    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
2206
	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2207 2208
    {
      add_key_field(key_fields,*and_level,
2209 2210
		    ((Item_field*) (cond_func->arguments()[0])->real_item())
		    ->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2211 2212 2213 2214 2215 2216 2217 2218 2219
		    cond_func->functype() == Item_func::ISNULL_FUNC,
		    new Item_null, usable_tables);
    }
    break;
  }
  return;
}

/*
2220 2221
  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
2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239
*/

static uint
max_part_bit(key_map bits)
{
  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;

2240
  if (key_field->eq_func && !(key_field->optimize & KEY_OPTIMIZE_EXISTS))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257
  {
    for (uint key=0 ; key < form->keys ; key++)
    {
      if (!(form->keys_in_use_for_query & (((key_map) 1) << key)))
	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;
2258
	  keyuse.keypart_map= (key_part_map) 1 << part;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2259
	  keyuse.used_tables=key_field->val->used_tables();
2260
	  keyuse.optimize= key_field->optimize & KEY_OPTIMIZE_REF_OR_NULL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271
	  VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
	}
      }
    }
  }
  /* Mark that we can optimize LEFT JOIN */
  if (key_field->val->type() == Item::NULL_ITEM &&
      !key_field->field->real_maybe_null())
    key_field->field->table->reginfo.not_exists_optimize=1;
}

monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2272 2273 2274

#define FT_KEYPART   (MAX_REF_PARTS+10)

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2275 2276 2277 2278
static void
add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
            JOIN_TAB *stat,COND *cond,table_map usable_tables)
{
2279
  Item_func_match *cond_func=NULL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2280

2281 2282 2283
  if (!cond)
    return;

2284 2285
  if (cond->type() == Item::FUNC_ITEM)
  {
2286 2287 2288
    Item_func *func=(Item_func *)cond;
    Item_func::Functype functype=  func->functype();
    if (functype == Item_func::FT_FUNC)
2289
      cond_func=(Item_func_match *)cond;
2290 2291 2292 2293
    else if (func->arg_count == 2)
    {
      Item_func *arg0=(Item_func *)(func->arguments()[0]),
                *arg1=(Item_func *)(func->arguments()[1]);
2294 2295 2296 2297 2298
      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)
2299
        cond_func=(Item_func_match *) arg0;
2300 2301 2302
      else if (arg0->const_item() &&
               ((functype == Item_func::LE_FUNC && arg0->val()> 0) ||
                (functype == Item_func::LT_FUNC && arg0->val()>=0)) &&
2303
                arg1->type() == Item::FUNC_ITEM          &&
2304
                arg1->functype() == Item_func::FT_FUNC)
2305 2306
        cond_func=(Item_func_match *) arg1;
    }
2307 2308 2309
  }
  else if (cond->type() == Item::COND_ITEM)
  {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
2310
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
2311 2312 2313 2314 2315

    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
      Item *item;
      while ((item=li++))
2316
        add_ft_keys(keyuse_array,stat,item,usable_tables);
2317 2318 2319
    }
  }

2320 2321
  if (!cond_func || cond_func->key == NO_SUCH_KEY ||
      !(usable_tables & cond_func->table->map))
2322
    return;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2323 2324 2325

  KEYUSE keyuse;
  keyuse.table= cond_func->table;
2326
  keyuse.val =  cond_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2327
  keyuse.key =  cond_func->key;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2328
  keyuse.keypart= FT_KEYPART;
2329
  keyuse.used_tables=cond_func->key_item()->used_tables();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2330 2331 2332
  VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
}

2333

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2334 2335 2336
static int
sort_keyuse(KEYUSE *a,KEYUSE *b)
{
2337
  int res;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2338 2339 2340 2341 2342 2343
  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);
2344
  // Place const values before other ones
2345 2346
  if ((res= test((a->used_tables & ~OUTER_REF_TABLE_BIT)) -
       test((b->used_tables & ~OUTER_REF_TABLE_BIT))))
2347 2348 2349 2350
    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
2351 2352 2353 2354
}


/*
2355 2356 2357
  Update keyuse array with all possible keys we can use to fetch rows
  join_tab is a array in tablenr_order
  stat is a reference array in 'prefered' order.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2358 2359 2360
*/

static bool
2361
update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
2362 2363
		    uint tables, COND *cond, table_map normal_tables,
		    SELECT_LEX *select_lex)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2364 2365
{
  uint	and_level,i,found_eq_constant;
2366
  KEY_FIELD *key_fields,*end;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2367

2368
  if (!(key_fields=(KEY_FIELD*)
monty@mashka.mysql.fi's avatar
merge  
monty@mashka.mysql.fi committed
2369 2370
	thd->alloc(sizeof(key_fields[0])*
		   (thd->lex.current_select->cond_count+1)*2)))
2371 2372 2373 2374 2375
    return TRUE; /* purecov: inspected */
  and_level=0; end=key_fields;
  if (cond)
    add_key_fields(join_tab,&end,&and_level,cond,normal_tables);
  for (i=0 ; i < tables ; i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2376
  {
2377
    if (join_tab[i].on_expr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2378
    {
2379 2380
      add_key_fields(join_tab,&end,&and_level,join_tab[i].on_expr,
		     join_tab[i].table->map);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2381 2382
    }
  }
2383 2384 2385 2386 2387
  if (my_init_dynamic_array(keyuse,sizeof(KEYUSE),20,64))
    return TRUE;
  /* fill keyuse with found key parts */
  for (KEY_FIELD *field=key_fields ; field != end ; field++)
    add_key_part(keyuse,field);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2388

2389
  if (select_lex->ftfunc_list->elements)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2390 2391 2392 2393 2394
  {
    add_ft_keys(keyuse,join_tab,cond,normal_tables);
  }

  /*
2395
    Special treatment for ft-keys.
2396 2397 2398
    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
2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415
  */
  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)
2416
	use->table->const_key_parts[use->key]|= use->keypart_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2417 2418
      if (use->keypart != FT_KEYPART)
      {
2419 2420 2421 2422 2423 2424 2425 2426
	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
2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444
      }

      *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;
      use->table->reginfo.join_tab->checked_keys|= (key_map) 1 << use->key;
      save_pos++;
    }
    i=(uint) (save_pos-(KEYUSE*) keyuse->buffer);
    VOID(set_dynamic(keyuse,(gptr) &end,i));
    keyuse->elements=i;
  }
  return FALSE;
}

2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476
/*
  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.
    */
    keyuse->ref_table_rows= ~(table_map) 0;	// If no ref
    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);
      }
    }
2477 2478 2479 2480 2481 2482
    /*
      Outer reference (external field) is constant for single executing
      of subquery
    */
    if (keyuse->used_tables == OUTER_REF_TABLE_BIT)
      keyuse->ref_table_rows= 1;
2483 2484 2485
  }
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2486 2487

/*****************************************************************************
2488 2489
  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
2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503
*****************************************************************************/

/* 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];
2504
  for (;next != table ; pos++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527
  {
    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)
{
2528
  ha_rows rec;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2529
  double tmp;
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2530
  THD *thd= join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561

  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 &&
	join->sort_by_table != join->positions[join->const_tables].table->table)
      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;
2562
      uint best_max_key_part=0;
2563
      my_bool found_constrain= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2564 2565 2566 2567 2568 2569

      if (s->keyuse)
      {						/* Use key if possible */
	TABLE *table=s->table;
	KEYUSE *keyuse,*start_key=0;
	double best_records=DBL_MAX;
2570
	uint max_key_part=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2571 2572

	/* Test how we can use keys */
2573
	rec= s->records/MATCHING_ROWS_IN_OTHER_TABLE;  // Assumed records/key
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2574 2575 2576 2577 2578 2579 2580
	for (keyuse=s->keyuse ; keyuse->table == table ;)
	{
	  key_map found_part=0;
	  table_map found_ref=0;
	  uint key=keyuse->key;
	  KEY *keyinfo=table->key_info+key;
          bool ft_key=(keyuse->keypart == FT_KEYPART);
2581
	  uint found_ref_or_null= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2582

2583
	  /* Calculate how many key segments of the current key we can use */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2584 2585 2586 2587
	  start_key=keyuse;
	  do
	  {
            uint keypart=keyuse->keypart;
2588
	    uint found_part_ref_or_null= KEY_OPTIMIZE_REF_OR_NULL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2589 2590
	    do
	    {
2591 2592 2593 2594 2595 2596 2597 2598
	      if (!(rest_tables & keyuse->used_tables) &&
		  !(found_ref_or_null & keyuse->optimize))
	      {
		found_part|=keyuse->keypart_map;
		found_ref|= keyuse->used_tables;
		if (rec > keyuse->ref_table_rows)
		  rec= keyuse->ref_table_rows;
		found_part_ref_or_null&= keyuse->optimize;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2599 2600
              }
	      keyuse++;
2601
	      found_ref_or_null|= found_part_ref_or_null;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2602 2603 2604 2605 2606
	    } while (keyuse->table == table && keyuse->key == key &&
		     keyuse->keypart == keypart);
	  } while (keyuse->table == table && keyuse->key == key);

	  /*
2607
	    Assume that that each key matches a proportional part of table.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2608 2609 2610
	  */
          if (!found_part && !ft_key)
	    continue;				// Nothing usable found
2611 2612
	  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
2613 2614

          /*
2615
	    ft-keys require special treatment
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2616 2617 2618 2619
          */
          if (ft_key)
          {
            /*
2620 2621
	      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
2622 2623 2624 2625 2626 2627
            */
            tmp=prev_record_reads(join,found_ref);
            records=1.0;
          }
          else
          {
2628
	  found_constrain= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2629
	  /*
2630
	    Check if we found full key
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2631
	  */
2632 2633
	  if (found_part == PREV_BITS(uint,keyinfo->key_parts) &&
	      !found_ref_or_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2634
	  {				/* use eq key */
2635
	    max_key_part= (uint) ~0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2636 2637 2638 2639 2640 2641 2642
	    if ((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY)) == HA_NOSAME)
	    {
	      tmp=prev_record_reads(join,found_ref);
	      records=1.0;
	    }
	    else
	    {
2643 2644
	      if (!found_ref)
	      {					// We found a const key
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2645 2646 2647
		if (table->quick_keys & ((key_map) 1 << key))
		  records= (double) table->quick_rows[key];
		else
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
2648 2649 2650 2651
		{
		  /* quick_range couldn't use key! */
		  records= (double) s->records/rec;
		}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665
	      }
	      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
		}
	      }
2666 2667 2668
	      /* Limit the number of matched rows */
	      tmp= records;
	      set_if_smaller(tmp, (double) thd->variables.max_seeks_for_key);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2669 2670 2671 2672
	      if (table->used_keys & ((key_map) 1 << key))
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
2673
		  (keyinfo->key_length+table->file->ref_length)+1;
2674
		tmp=record_count*(tmp+keys_per_block-1)/keys_per_block;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2675 2676
	      }
	      else
2677
		tmp=record_count*min(tmp,s->worst_seeks);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2678 2679 2680 2681 2682
	    }
	  }
	  else
	  {
	    /*
2683 2684 2685
	      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
2686
	    */
2687
	    if ((found_part & 1) &&
2688 2689
		(!(table->file->index_flags(key) & HA_ONLY_WHOLE_INDEX) ||
		 found_part == PREV_BITS(uint,keyinfo->key_parts)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2690
	    {
2691
	      max_key_part=max_part_bit(found_part);
2692 2693 2694 2695
	      /*
		Check if quick_range could determinate how many rows we
		will match
	      */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706
	      if (table->quick_keys & ((key_map) 1 << key) &&
		  table->quick_key_parts[key] <= max_key_part)
		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
		{
		  /*
2707
		    Assume that the first key part matches 1% of the file
2708
		    and that the hole key matches 10 (duplicates) or 1
2709 2710 2711 2712 2713
		    (unique) records.
		    Assume also that more key matches proportionally more
		    records
		    This gives the formula:
		    records= (x * (b-a) + a*c-b)/(c-1)
2714

2715 2716 2717 2718
		    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
2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
		  */
		  double rec_per_key;
		  if (!(rec_per_key=(double)
			keyinfo->rec_per_key[keyinfo->key_parts-1]))
		    rec_per_key=(double) s->records/rec+1;

		  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;
		}
2739 2740 2741 2742 2743 2744
		if (found_ref_or_null)
		{
		  /* 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
2745
	      }
2746 2747
	      /* Limit the number of matched rows */
	      set_if_smaller(tmp, (double) thd->variables.max_seeks_for_key);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2748 2749 2750 2751
	      if (table->used_keys & ((key_map) 1 << key))
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
2752
		  (keyinfo->key_length+table->file->ref_length)+1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2753 2754 2755 2756 2757 2758 2759 2760
		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
	  }
2761
          } /* not ft_key */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2762 2763 2764 2765 2766 2767
	  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;
2768
	    best_max_key_part=max_key_part;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2769 2770 2771 2772
	  }
	}
	records=best_records;
      }
2773 2774 2775 2776

      /*
	Don't test table scan if it can't be better.
	Prefer key lookup if we would use the same key for scanning.
2777 2778 2779 2780 2781

	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.
2782 2783 2784
      */
      if ((records >= s->found_records || best > s->read_time) &&
	  !(s->quick && best_key && s->quick->index == best_key->key &&
2785
	    best_max_key_part >= s->table->quick_key_parts[best_key->key]) &&
2786
	  !((s->table->file->table_flags() & HA_TABLE_SCAN_ON_INDEX) &&
2787 2788
	    s->table->used_keys && best_key) &&
	  !(s->table->force_index && best_key))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2789
      {						// Check full join
2790
	ha_rows rnd_records= s->found_records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2791 2792
	if (s->on_expr)
	{
2793
	  tmp=rows2double(rnd_records);		// Can't use read cache
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2794 2795 2796 2797
	}
	else
	{
	  tmp=(double) s->read_time;
2798
	  /* Calculate time to read previous rows through cache */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2799
	  tmp*=(1.0+floor((double) cache_record_length(join,idx)*
2800 2801
			  record_count /
			  (double) thd->variables.join_buff_size));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2802
	}
2803 2804 2805 2806 2807 2808 2809 2810 2811 2812

	/*
	  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_constrain)
	  rnd_records-= rnd_records/4;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2813
	if (best == DBL_MAX ||
2814
	    (tmp  + record_count/(double) TIME_FOR_COMPARE*rnd_records <
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2815 2816
	     best + record_count/(double) TIME_FOR_COMPARE*records))
	{
2817 2818 2819 2820
	  /*
	    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
2821
	  best=tmp;
2822
	  records= rows2double(rnd_records);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2823 2824 2825
	  best_key=0;
	}
      }
2826
      join->positions[idx].records_read= records;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2827 2828 2829
      join->positions[idx].key=best_key;
      join->positions[idx].table= s;
      if (!best_key && idx == join->const_tables &&
2830
	  s->table == join->sort_by_table &&
2831
	  join->unit->select_limit_cnt >= records)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853
	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;
	}
	swap(JOIN_TAB*,join->best_ref[idx],*pos);
	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
2854 2855
        if (thd->killed)
          return;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2856 2857 2858 2859 2860 2861 2862 2863 2864 2865
	swap(JOIN_TAB*,join->best_ref[idx],*pos);
      }
      if (join->select_options & SELECT_STRAIGHT_JOIN)
	break;				// Don't test all combinations
    }
  }
}


/*
2866
  Find how much space the prevous read not const tables takes in cache
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2867 2868
*/

2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903
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
2904 2905 2906
static uint
cache_record_length(JOIN *join,uint idx)
{
2907
  uint length=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2908
  JOIN_TAB **pos,**end;
2909
  THD *thd=join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2910 2911 2912 2913 2914 2915

  for (pos=join->best_ref+join->const_tables,end=join->best_ref+idx ;
       pos != end ;
       pos++)
  {
    JOIN_TAB *join_tab= *pos;
2916 2917
    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
2918 2919 2920 2921 2922 2923 2924 2925 2926 2927
    length+=join_tab->used_fieldlength;
  }
  return length;
}


static double
prev_record_reads(JOIN *join,table_map found_ref)
{
  double found=1.0;
2928
  found_ref&= ~OUTER_REF_TABLE_BIT;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941
  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;
}


/*****************************************************************************
2942
  Set up join struct according to best position.
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2943 2944 2945 2946 2947
*****************************************************************************/

static bool
get_best_combination(JOIN *join)
{
2948
  uint i,tablenr;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2949 2950 2951 2952
  table_map used_tables;
  JOIN_TAB *join_tab,*j;
  KEYUSE *keyuse;
  uint table_count;
2953
  THD *thd=join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2954 2955 2956

  table_count=join->tables;
  if (!(join->join_tab=join_tab=
2957
	(JOIN_TAB*) thd->alloc(sizeof(JOIN_TAB)*table_count)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2958 2959 2960 2961
    return TRUE;

  join->full_join=0;

2962
  used_tables= OUTER_REF_TABLE_BIT;		// Outer row is already read
bk@work.mysql.com's avatar
bk@work.mysql.com committed
2963 2964 2965 2966 2967 2968 2969 2970 2971
  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
2972 2973 2974 2975 2976
    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
2977 2978 2979 2980 2981 2982 2983 2984 2985

    if (j->type == JT_SYSTEM)
      continue;
    if (!j->keys || !(keyuse= join->best_positions[tablenr].key))
    {
      j->type=JT_ALL;
      if (tablenr != join->const_tables)
	join->full_join=1;
    }
2986 2987 2988
    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
2989

2990 2991 2992 2993 2994
  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;
}
2995

bk@work.mysql.com's avatar
bk@work.mysql.com committed
2996

2997 2998 2999 3000 3001 3002 3003 3004 3005
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;
3006

3007
  /*  Use best key from find_best */
3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022
  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;
3023 3024 3025 3026 3027 3028
    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
    */
3029 3030
    do
    {
3031
      if (!(~used_tables & keyuse->used_tables))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3032
      {
3033 3034
	if (keyparts == keyuse->keypart &&
	    !(found_part_ref_or_null & keyuse->optimize))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3035
	{
3036
	  keyparts++;
3037 3038
	  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
3039 3040
	}
      }
3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060
      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;
  keyuse=org_keyuse;

3061 3062
  store_key **ref_key= j->ref.key_copy;
  byte *key_buff=j->ref.key_buff, *null_ref_key= 0;
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084
  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
      if (!keyuse->used_tables &&
	  !(join->select_options & SELECT_DESCRIBE))
      {					// Compare against constant
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
3085 3086 3087 3088
	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);
3089
	if (thd->is_fatal_error)
3090
	  return TRUE;
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
3091
	tmp.copy();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3092 3093
      }
      else
3094 3095 3096 3097
	*ref_key++= get_store_key(thd,
				  keyuse,join->const_table_map,
				  &keyinfo->key_part[i],
				  (char*) key_buff,maybe_null);
3098 3099 3100
      /* Remmeber if we are going to use REF_OR_NULL */
      if (keyuse->optimize & KEY_OPTIMIZE_REF_OR_NULL)
	null_ref_key= key_buff;
3101
      key_buff+=keyinfo->key_part[i].store_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3102
    }
3103 3104
  } /* not ftkey */
  *ref_key=0;				// end_marker
3105 3106 3107 3108
  if (j->type == JT_FT)
    return 0;
  if (j->type == JT_CONST)
    j->table->const_table= 1;
3109
  else if (((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY))
3110 3111 3112 3113 3114 3115 3116
	    != HA_NOSAME) || keyparts != keyinfo->key_parts ||
	   null_ref_key)
  {
    /* Must read with repeat */
    j->type= null_ref_key ? JT_REF_OR_NULL : JT_REF;
    j->null_ref_key= null_ref_key;
  }
3117
  else if (ref_key == j->ref.key_copy)
3118
  {
3119 3120 3121 3122 3123 3124 3125 3126
    /*
      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
3127
  }
3128 3129
  else
    j->type=JT_EQ_REF;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3130 3131 3132 3133
  return 0;
}


3134

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3135
static store_key *
3136 3137
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
3138 3139 3140
{
  if (!((~used_tables) & keyuse->used_tables))		// if const item
  {
3141 3142
    return new store_key_const_item(thd,
				    key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3143 3144 3145 3146 3147 3148
				    key_buff + maybe_null,
				    maybe_null ? key_buff : 0,
				    key_part->length,
				    keyuse->val);
  }
  else if (keyuse->val->type() == Item::FIELD_ITEM)
3149 3150
    return new store_key_field(thd,
			       key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3151 3152 3153 3154 3155
			       key_buff + maybe_null,
			       maybe_null ? key_buff : 0,
			       key_part->length,
			       ((Item_field*) keyuse->val)->field,
			       keyuse->val->full_name());
3156 3157
  return new store_key_item(thd,
			    key_part->field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3158 3159 3160 3161 3162 3163 3164
			    key_buff + maybe_null,
			    maybe_null ? key_buff : 0,
			    key_part->length,
			    keyuse->val);
}

/*
3165 3166
  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
3167 3168 3169 3170 3171
*/

bool
store_val_in_field(Field *field,Item *item)
{
3172
  bool error;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3173
  THD *thd=current_thd;
3174
  ha_rows cuted_fields=thd->cuted_fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3175
  thd->count_cuted_fields=1;
3176
  error= item->save_in_field(field, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3177
  thd->count_cuted_fields=0;
3178
  return error || cuted_fields != thd->cuted_fields;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3179 3180 3181 3182 3183 3184 3185 3186 3187
}


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

3188 3189
  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
3190 3191 3192 3193 3194 3195
    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
3196 3197 3198
  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
3199
  join->first_record=join->sort_and_group=0;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
3200
  join->send_records=(ha_rows) 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3201
  join->group=0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3202
  join->row_limit=join->unit->select_limit_cnt;
3203
  join->do_send_rows = (join->row_limit) ? 1 : 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214

  join_tab->cache.buff=0;			/* No cacheing */
  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 */
  join_tab->keys= (uint) ~0;			/* test everything in quick */
  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
3215 3216
  join_tab->not_used_in_distinct=0;
  join_tab->read_first_record= join_init_read_record;
3217
  join_tab->join=join;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
3218
  bzero((char*) &join_tab->read_record,sizeof(join_tab->read_record));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238
  tmp_table->status=0;
  tmp_table->null_row=0;
  return FALSE;
}


static bool
make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
{
  DBUG_ENTER("make_join_select");
  if (select)
  {
    table_map used_tables;
    if (join->tables > 1)
      cond->update_used_tables();		// Tablenr may have changed
    {						// 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())
3239 3240
      {
	DBUG_PRINT("info",("Found impossible WHERE condition"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3241
	DBUG_RETURN(1);				// Impossible const condition
3242
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3243
    }
3244 3245
    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
3246 3247 3248 3249
    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
3250 3251 3252 3253
      /*
	Following force including random expression in last table condition.
	It solve problem with select like SELECT * FROM t1 WHERE rand() > 0.5
      */
3254
      if (i == join->tables-1)
3255
	current_map|= OUTER_REF_TABLE_BIT | RAND_TABLE_BIT;
3256
      bool use_quick_range=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3257
      used_tables|=current_map;
3258 3259

      if (tab->type == JT_REF && tab->quick &&
3260
	  (uint) tab->ref.key == tab->quick->index &&
3261 3262 3263 3264 3265 3266 3267
	  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;
	tab->ref.key_parts=0;		// Don't use ref key.
3268
	join->best_positions[i].records_read= rows2double(tab->quick->records);
3269 3270
      }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3271
      COND *tmp=make_cond_for_table(cond,used_tables,current_map);
3272 3273 3274 3275 3276 3277 3278 3279
      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
3280 3281 3282 3283
      if (tmp)
      {
	DBUG_EXECUTE("where",print_where(tmp,tab->table->table_name););
	SQL_SELECT *sel=tab->select=(SQL_SELECT*)
3284
	  join->thd->memdup((gptr) select, sizeof(SQL_SELECT));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3285 3286 3287 3288 3289 3290
	if (!sel)
	  DBUG_RETURN(1);			// End of memory
	tab->select_cond=sel->cond=tmp;
	sel->head=tab->table;
	if (tab->quick)
	{
3291 3292
	  /* Use quick key read if it's a constant and it's not used
	     with key reading */
3293 3294
	  if (tab->needed_reg == 0 && tab->type != JT_EQ_REF
	      && tab->type != JT_FT && (tab->type != JT_REF ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312
	       (uint) tab->ref.key == tab->quick->index))
	  {
	    sel->quick=tab->quick;		// Use value from get_quick_...
	    sel->quick_keys=0;
	    sel->needed_reg=0;
	  }
	  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)
	{
	  if (tab->const_keys && tab->table->reginfo.impossible_range)
	    DBUG_RETURN(1);
	}
3313
	else if (tab->type == JT_ALL && ! use_quick_range)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3314 3315 3316 3317 3318 3319
	{
	  if (tab->const_keys &&
	      tab->table->reginfo.impossible_range)
	    DBUG_RETURN(1);				// Impossible range
	  /*
	    We plan to scan all rows.
3320 3321 3322
	    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
3323 3324 3325
	  */

	  if ((tab->keys & ~ tab->const_keys && i > 0) ||
3326
	      (tab->const_keys && i == join->const_tables &&
3327 3328
	       join->unit->select_limit_cnt < 
	       join->best_positions[i].records_read &&
3329
	       !(join->select_options & OPTION_FOUND_ROWS)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3330 3331 3332
	  {
	    if (sel->test_quick_select(tab->keys,
				       used_tables & ~ current_map,
3333 3334 3335
				       (join->select_options &
					OPTION_FOUND_ROWS ?
					HA_POS_ERROR :
3336
					join->unit->select_limit_cnt)) < 0)
3337
	      DBUG_RETURN(1);				// Impossible range
3338 3339 3340
	    /* 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
3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354
	  }
	  else
	  {
	    sel->needed_reg=tab->needed_reg;
	    sel->quick_keys=0;
	  }
	  if ((sel->quick_keys | sel->needed_reg) & ~tab->checked_keys)
	  {
	    tab->keys=sel->quick_keys | sel->needed_reg;
	    tab->use_quick= (sel->needed_reg &&
			     (!select->quick_keys ||
			      (select->quick &&
			       (select->quick->records >= 100L)))) ?
	      2 : 1;
hf@deer.(none)'s avatar
hf@deer.(none) committed
3355
	    sel->read_tables= used_tables & ~current_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3356 3357 3358 3359 3360 3361 3362 3363 3364
	  }
	  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"););
3365 3366
	      tab->cache.select=(SQL_SELECT*)
		join->thd->memdup((gptr) sel, sizeof(SQL_SELECT));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379
	      tab->cache.select->cond=tmp;
	      tab->cache.select->read_tables=join->const_table_map;
	    }
	  }
	}
      }
    }
  }
  DBUG_RETURN(0);
}


static void
3380
make_join_readinfo(JOIN *join, uint options)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3381 3382
{
  uint i;
3383
  SELECT_LEX *select_lex = &(join->thd->lex.select_lex);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405
  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 */
    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;
      break;
    case JT_EQ_REF:
      table->status=STATUS_NO_RECORD;
3406 3407 3408 3409 3410
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3411 3412 3413 3414 3415
      delete tab->quick;
      tab->quick=0;
      table->file->index_init(tab->ref.key);
      tab->read_first_record= join_read_key;
      tab->read_record.read_record= join_no_more_records;
3416 3417
      if (table->used_keys & ((key_map) 1 << tab->ref.key) &&
	  !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3418 3419 3420 3421 3422
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
      break;
3423
    case JT_REF_OR_NULL:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3424 3425
    case JT_REF:
      table->status=STATUS_NO_RECORD;
3426 3427 3428 3429 3430
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3431 3432 3433
      delete tab->quick;
      tab->quick=0;
      table->file->index_init(tab->ref.key);
3434 3435
      if (table->used_keys & ((key_map) 1 << tab->ref.key) &&
	  !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3436 3437 3438 3439
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
3440 3441 3442 3443 3444 3445 3446 3447 3448 3449
      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
3450 3451 3452 3453 3454 3455 3456 3457 3458
      break;
    case JT_FT:
      table->status=STATUS_NO_RECORD;
      table->file->index_init(tab->ref.key);
      tab->read_first_record= join_ft_read_first;
      tab->read_record.read_record= join_ft_read_next;
      break;
    case JT_ALL:
      /*
3459
	If previous table use cache
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3460 3461
      */
      table->status=STATUS_NO_RECORD;
3462
      if (i != join->const_tables && !(options & SELECT_NO_JOIN_CACHE) &&
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473
	  tab->use_quick != 2 && !tab->on_expr)
      {
	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)
3474
      {
3475
	select_lex->options|=QUERY_NO_GOOD_INDEX_USED;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3476
	tab->read_first_record= join_init_quick_read_record;
3477 3478
	statistic_increment(select_range_check_count, &LOCK_status);
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3479 3480 3481
      else
      {
	tab->read_first_record= join_init_read_record;
3482 3483 3484 3485 3486 3487 3488 3489
	if (i == join->const_tables)
	{
	  if (tab->select && tab->select->quick)
	  {
	    statistic_increment(select_range_count, &LOCK_status);
	  }
	  else
	  {
3490
	    select_lex->options|=QUERY_NO_INDEX_USED;
3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501
	    statistic_increment(select_scan_count, &LOCK_status);
	  }
	}
	else
	{
	  if (tab->select && tab->select->quick)
	  {
	    statistic_increment(select_full_range_join_count, &LOCK_status);
	  }
	  else
	  {
3502
	    select_lex->options|=QUERY_NO_INDEX_USED;
3503 3504 3505
	    statistic_increment(select_full_join_count, &LOCK_status);
	  }
	}
3506
	if (!table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3507
	{
3508 3509 3510 3511 3512 3513 3514 3515 3516 3517
	  if (tab->select && tab->select->quick &&
	      table->used_keys & ((key_map) 1 << tab->select->quick->index))
	  {
	    table->key_read=1;
	    table->file->extra(HA_EXTRA_KEYREAD);
	  }
	  else if (table->used_keys && ! (tab->select && tab->select->quick))
	  {					// Only read index tree
	    tab->index=find_shortest_key(table, table->used_keys);
	    tab->table->file->index_init(tab->index);
3518
	    tab->read_first_record= join_read_first;
3519 3520
	    tab->type=JT_NEXT;		// Read with index_first / index_next
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536
	}
      }
      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;
}


3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558
/*
  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++)
  {
3559
    if (tab->type == JT_ALL && (!tab->select || !tab->select->quick))
3560 3561 3562 3563 3564 3565 3566 3567 3568
    {
      my_error(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE,MYF(0));
      return(1);
    }
  }
  return(0);
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
3569
static void
3570
join_free(JOIN *join, bool full)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3571 3572
{
  JOIN_TAB *tab,*end;
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
3573
  DBUG_ENTER("join_free");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3574 3575 3576

  if (join->table)
  {
3577 3578 3579 3580 3581
    /*
      Only a sorted table may be cached.  This sorted table is always the
      first non const table in join->table
    */
    if (join->tables > join->const_tables) // Test for not-const tables
3582
    {
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3583
      free_io_cache(join->table[join->const_tables]);
3584 3585
      filesort_free_buffers(join->table[join->const_tables]);
    }
3586
    if (join->select_lex->dependent && !full)
3587
    {
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601
      for (tab=join->join_tab,end=tab+join->tables ; tab != end ; tab++)
      {
	if (tab->table)
	{
	  if (tab->table->key_read)
	  {
	    tab->table->key_read= 0;
	    tab->table->file->extra(HA_EXTRA_NO_KEYREAD);
	  }
	  /* Don't free index if we are using read_record */
	  if (!tab->read_record.table)
	    tab->table->file->index_end();
	}
      }
3602
    }
3603
    else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3604
    {
3605
      for (tab=join->join_tab,end=tab+join->tables ; tab != end ; tab++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3606
      {
3607 3608 3609 3610
	delete tab->select;
	delete tab->quick;
	tab->select=0;
	tab->quick=0;
3611
	x_free(tab->cache.buff);
3612
	tab->cache.buff= 0;
3613
	if (tab->table)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3614
	{
3615 3616 3617 3618 3619 3620 3621 3622
	  if (tab->table->key_read)
	  {
	    tab->table->key_read= 0;
	    tab->table->file->extra(HA_EXTRA_NO_KEYREAD);
	  }
	  /* Don't free index if we are using read_record */
	  if (!tab->read_record.table)
	    tab->table->file->index_end();
3623 3624 3625 3626 3627
	  /*
	    We need to reset this for next select
	    (Tested in part_of_refkey)
	  */
	  tab->table->reginfo.join_tab= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3628
	}
3629
	end_read_record(&tab->read_record);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3630
      }
3631
      join->table= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3632 3633
    }
  }
3634 3635 3636 3637
  /*
    We are not using tables anymore
    Unlock all tables. We may be in an INSERT .... SELECT statement.
  */
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
3638 3639
  if (join->lock && join->thd->lock &&
      !(join->select_options & SELECT_NO_UNLOCK))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3640 3641 3642 3643
  {
    mysql_unlock_read_tables(join->thd, join->lock);// Don't free join->lock
    join->lock=0;
  }
3644 3645 3646 3647 3648 3649
  if (full)
  {
    join->group_fields.delete_elements();
    join->tmp_table_param.copy_funcs.delete_elements();
    join->tmp_table_param.cleanup();
  }
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
3650
  DBUG_VOID_RETURN;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3651 3652 3653 3654
}


/*****************************************************************************
3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667
  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
3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691
*****************************************************************************/

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 */
  if (tab->type != JT_EQ_REF)
    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)
      {
3692
	if ((*ref_item)->eq(order->item[0],0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3693 3694 3695 3696 3697
	  break;
      }
      if (order)
      {
	found++;
monty@bitch.mysql.fi's avatar
monty@bitch.mysql.fi committed
3698
	DBUG_ASSERT(!(order->used & map));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3699 3700 3701 3702 3703 3704 3705 3706
	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 */
3707
  for (; found && start_order ; start_order=start_order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724
  {
    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)
3725
    return 0;			// skip this optimize /* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740
  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;

3741
  for (; join_tab != end ; join_tab++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3742 3743 3744 3745 3746 3747 3748
  {
    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();
3749
    ref->depend_map=depend_map & ~OUTER_REF_TABLE_BIT;
3750
    depend_map&= ~OUTER_REF_TABLE_BIT;
3751
    for (JOIN_TAB **tab=join->map2table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3752
	 depend_map ;
3753
	 tab++,depend_map>>=1 )
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3754 3755
    {
      if (depend_map & 1)
3756
	ref->depend_map|=(*tab)->ref.depend_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3757 3758 3759 3760 3761 3762 3763 3764 3765
    }
  }
}


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

static void update_depend_map(JOIN *join, ORDER *order)
{
3766
  for (; order ; order=order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3767 3768 3769 3770
  {
    table_map depend_map;
    order->item[0]->update_used_tables();
    order->depend_map=depend_map=order->item[0]->used_tables();
3771 3772
    // 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
3773
    {
3774
      for (JOIN_TAB **tab=join->map2table;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3775
	   depend_map ;
3776
	   tab++, depend_map>>=1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3777 3778
      {
	if (depend_map & 1)
3779
	  order->depend_map|=(*tab)->ref.depend_map;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3780 3781 3782 3783 3784 3785 3786
      }
    }
  }
}


/*
3787 3788
  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
3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814
*/

static ORDER *
remove_const(JOIN *join,ORDER *first_order, COND *cond, bool *simple_order)
{
  if (join->tables == join->const_tables)
    return 0;					// No need to sort
  DBUG_ENTER("remove_const");
  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;
  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))
    {
      DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
3815
      continue;					// skip const item
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3816 3817 3818
    }
    else
    {
3819
      if (order_tables & (RAND_TABLE_BIT | OUTER_REF_TABLE_BIT))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849
	*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)))
	{
	  if (only_eq_ref_tables(join,first_order,ref))
	  {
	    DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
	    continue;
	  }
	  *simple_order=0;			// Must do a temp table to sort
	}
      }
    }
    *prev_ptr= order;				// use this entry
    prev_ptr= &order->next;
  }
  *prev_ptr=0;
  if (!first_order)				// Nothing to sort/group
    *simple_order=1;
  DBUG_PRINT("exit",("simple_order: %d",(int) *simple_order));
  DBUG_RETURN(first_order);
}

3850

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3851
static int
3852 3853
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
3854 3855
		 const char *info, Item *having, Procedure *procedure,
		 SELECT_LEX_UNIT *unit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3856 3857 3858 3859
{
  DBUG_ENTER("return_zero_rows");

  if (select_options & SELECT_DESCRIBE)
3860
  {	
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3861
    select_describe(join, false, false, false, info);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3862 3863
    DBUG_RETURN(0);
  }
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
3864

bk@work.mysql.com's avatar
bk@work.mysql.com committed
3865 3866
  if (procedure)
  {
3867
    if (result->prepare(fields, unit))		// This hasn't been done yet
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3868 3869 3870 3871 3872 3873
      DBUG_RETURN(-1);
  }
  if (send_row)
  {
    for (TABLE_LIST *table=tables; table ; table=table->next)
      mark_as_null_row(table->table);		// All fields are NULL
3874
    if (having && having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3875 3876
      send_row=0;
  }
3877
  if (!(result->send_fields(fields,1)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3878 3879
  {
    if (send_row)
3880 3881 3882 3883 3884
    {
      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
3885
      result->send_data(fields);
3886
    }
3887
    if (tables)				// Not from do_select()
3888 3889 3890 3891 3892
    {
      /* Close open cursors */
      for (TABLE_LIST *table=tables; table ; table=table->next)
	table->table->file->index_end();
    }
3893
    result->send_eof();				// Should be safe
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905
  }
  DBUG_RETURN(0);
}


static void clear_tables(JOIN *join)
{
  for (uint i=0 ; i < join->tables ; i++)
    mark_as_null_row(join->table[i]);		// All fields are NULL
}

/*****************************************************************************
3906 3907 3908 3909 3910 3911
  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
3912 3913 3914 3915
*****************************************************************************/

class COND_CMP :public ilink {
public:
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
3916
  static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932
  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

/*
3933 3934
  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
3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959
*/

static void
change_cond_ref_to_const(I_List<COND_CMP> *save_list,Item *and_father,
			 Item *cond, Item *field, Item *value)
{
  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++))
      change_cond_ref_to_const(save_list,and_level ? cond : item, item,
			       field, value);
    return;
  }
  if (cond->eq_cmp_result() == Item::COND_OK)
    return;					// Not a boolean function

  Item_bool_func2 *func=  (Item_bool_func2*) cond;
  Item *left_item=  func->arguments()[0];
  Item *right_item= func->arguments()[1];
  Item_func::Functype functype=  func->functype();

3960
  if (right_item->eq(field,0) && left_item != value)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974
  {
    Item *tmp=value->new_item();
    if (tmp)
    {
      func->arguments()[1] = tmp;
      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);
      }
3975
      func->set_cmp_func();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3976 3977
    }
  }
3978
  else if (left_item->eq(field,0) && right_item != value)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994
  {
    Item *tmp=value->new_item();
    if (tmp)
    {
      func->arguments()[0] = value = tmp;
      func->update_used_tables();
      if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
	  && and_father != cond && !right_item->const_item())
      {
	func->arguments()[0] = func->arguments()[1]; // For easy check
	func->arguments()[1] = value;
	cond->marker=1;
	COND_CMP *tmp2;
	if ((tmp2=new COND_CMP(and_father,func)))
	  save_list->push_back(tmp2);
      }
3995
      func->set_cmp_func();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008
    }
  }
}


static void
propagate_cond_constants(I_List<COND_CMP> *save_list,COND *and_level,
			 COND *cond)
{
  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
4009
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036
    Item *item;
    I_List<COND_CMP> save;
    while ((item=li++))
    {
      propagate_cond_constants(&save,and_level ? cond : item, item);
    }
    if (and_level)
    {						// Handle other found items
      I_List_iterator<COND_CMP> cond_itr(save);
      COND_CMP *cond_cmp;
      while ((cond_cmp=cond_itr++))
	if (!cond_cmp->cmp_func->arguments()[0]->const_item())
	  change_cond_ref_to_const(&save,cond_cmp->and_level,
				   cond_cmp->and_level,
				   cond_cmp->cmp_func->arguments()[0],
				   cond_cmp->cmp_func->arguments()[1]);
    }
  }
  else if (and_level != cond && !cond->marker)		// In a AND group
  {
    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;
      bool left_const= func->arguments()[0]->const_item();
      bool right_const=func->arguments()[1]->const_item();
4037 4038 4039
      if (!(left_const && right_const) &&
	  (func->arguments()[0]->result_type() ==
	   (func->arguments()[1]->result_type())))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076
      {
	if (right_const)
	{
	  func->arguments()[1]=resolve_const_item(func->arguments()[1],
						  func->arguments()[0]);
	  func->update_used_tables();
	  change_cond_ref_to_const(save_list,and_level,and_level,
				   func->arguments()[0],
				   func->arguments()[1]);
	}
	else if (left_const)
	{
	  func->arguments()[0]=resolve_const_item(func->arguments()[0],
						  func->arguments()[1]);
	  func->update_used_tables();
	  change_cond_ref_to_const(save_list,and_level,and_level,
				   func->arguments()[1],
				   func->arguments()[0]);
	}
      }
    }
  }
}


static COND *
optimize_cond(COND *conds,Item::cond_result *cond_value)
{
  if (!conds)
  {
    *cond_value= Item::COND_TRUE;
    return conds;
  }
  /* change field = field to field = const for each found field = const */
  DBUG_EXECUTE("where",print_where(conds,"original"););
  propagate_cond_constants((I_List<COND_CMP> *) 0,conds,conds);
  /*
4077 4078
    Remove all instances of item == item
    Remove all and-levels where CONST item != CONST item
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4079 4080 4081 4082 4083 4084 4085 4086 4087
  */
  DBUG_EXECUTE("where",print_where(conds,"after const change"););
  conds=remove_eq_conds(conds,cond_value) ;
  DBUG_EXECUTE("info",print_where(conds,"after remove"););
  return conds;
}


/*
4088 4089 4090 4091 4092
  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
4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103
*/

static COND *
remove_eq_conds(COND *cond,Item::cond_result *cond_value)
{
  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;
4104
    bool should_fix_fields=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123

    *cond_value=Item::COND_UNDEF;
    Item *item;
    while ((item=li++))
    {
      Item *new_item=remove_eq_conds(item,&tmp_cond_value);
      if (!new_item)
      {
#ifdef DELETE_ITEMS
	delete item;				// This may be shared
#endif
	li.remove();
      }
      else if (item != new_item)
      {
#ifdef DELETE_ITEMS
	delete item;				// This may be shared
#endif
	VOID(li.replace(new_item));
4124
	should_fix_fields=1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150
      }
      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 */
      }
    }
4151
    if (should_fix_fields)
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
4152
      cond->fix_fields(current_thd,0, &cond);
4153

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167
    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)
  {
    /*
4168 4169 4170 4171 4172 4173 4174
      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
4175 4176 4177 4178
    */

    Item_func_isnull *func=(Item_func_isnull*) cond;
    Item **args= func->arguments();
4179
    THD *thd=current_thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4180 4181 4182 4183
    if (args[0]->type() == Item::FIELD_ITEM)
    {
      Field *field=((Item_field*) args[0])->field;
      if (field->flags & AUTO_INCREMENT_FLAG && !field->table->maybe_null &&
4184 4185
	  (thd->options & OPTION_AUTO_IS_NULL) &&
	  thd->insert_id())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4186
      {
4187
#ifndef EMBEDDED_LIBRARY
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
4188
	query_cache_abort(&thd->net);
4189
#endif
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4190 4191 4192
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],
					new Item_int("last_insert_id()",
4193
						     thd->insert_id(),
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4194 4195 4196
						     21))))
	{
	  cond=new_cond;
4197
	  cond->fix_fields(thd, 0, &cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4198
	}
4199
	thd->insert_id(0);		// Clear for next request
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4200 4201 4202 4203
      }
      /* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
      else if (((field->type() == FIELD_TYPE_DATE) ||
		(field->type() == FIELD_TYPE_DATETIME)) &&
4204 4205
		(field->flags & NOT_NULL_FLAG) &&
	       !field->table->maybe_null)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4206 4207 4208 4209 4210
      {
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
	{
	  cond=new_cond;
4211
	  cond->fix_fields(thd, 0, &cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224
	}
      }
    }
  }
  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];
4225
    if (left_item->eq(right_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4226 4227 4228 4229 4230 4231 4232
    {
      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;
4233
  return cond;					// Point at next and level
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4234 4235 4236
}

/*
4237
  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
4238 4239 4240 4241 4242 4243 4244 4245 4246
*/

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
4247
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269
    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];
4270
    if (left_item->eq(comp_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4271 4272 4273 4274
    {
      if (right_item->const_item())
      {
	if (*const_item)
4275
	  return right_item->eq(*const_item, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4276 4277 4278 4279
	*const_item=right_item;
	return 1;
      }
    }
4280
    else if (right_item->eq(comp_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4281 4282 4283 4284
    {
      if (left_item->const_item())
      {
	if (*const_item)
4285
	  return left_item->eq(*const_item, 1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4286 4287 4288 4289 4290 4291 4292 4293 4294 4295
	*const_item=left_item;
	return 1;
      }
    }
  }
  return 0;
}


/****************************************************************************
4296
  Create internal temporary table
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4297 4298
****************************************************************************/

4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323
/*
  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
    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
		       
  RETURN
    0			on error
    new_created field
*/

4324
Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4325
			Item ***copy_func, Field **from_field,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336
			bool group, bool modify_item)
{
  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
4337
				0, item->name,table,&my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4338 4339 4340
      else
	return new Field_double(item_sum->max_length,maybe_null,
				item->name, table, item_sum->decimals);
4341 4342
    case Item_sum::VARIANCE_FUNC:			/* Place for sum & count */
    case Item_sum::STD_FUNC:	
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4343 4344
      if (group)
	return	new Field_string(sizeof(double)*2+sizeof(longlong),
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
4345
				 0, item->name,table,&my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4346 4347
      else
	return new Field_double(item_sum->max_length, maybe_null,
4348
				item->name,table,item_sum->decimals);				
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4349 4350 4351 4352 4353 4354 4355 4356 4357
    case Item_sum::UNIQUE_USERS_FUNC:
      return new Field_long(9,maybe_null,item->name,table,1);
    default:
      switch (item_sum->result_type()) {
      case REAL_RESULT:
	return new Field_double(item_sum->max_length,maybe_null,
				item->name,table,item_sum->decimals);
      case INT_RESULT:
	return new Field_longlong(item_sum->max_length,maybe_null,
4358
				  item->name,table,item->unsigned_flag);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4359 4360 4361
      case STRING_RESULT:
	if (item_sum->max_length > 255)
	  return  new Field_blob(item_sum->max_length,maybe_null,
4362
				 item->name,table,item->collation.collation);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4363
	return	new Field_string(item_sum->max_length,maybe_null,
4364
				 item->name,table,item->collation.collation);
4365
      case ROW_RESULT:
4366
      default:
4367 4368 4369
	// This case should never be choosen
	DBUG_ASSERT(0);
	return 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4370 4371
      }
    }
4372
    thd->fatal_error();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4373 4374 4375 4376 4377 4378 4379
    return 0;					// Error
  }
  case Item::FIELD_ITEM:
  {
    Field *org_field=((Item_field*) item)->field,*new_field;

    *from_field=org_field;
4380 4381
    // The following should always be true
    if ((new_field= org_field->new_field(&thd->mem_root,table)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395
    {
      if (modify_item)
	((Item_field*) item)->result_field= new_field;
      else
	new_field->field_name=item->name;
      if (org_field->maybe_null())
	new_field->flags&= ~NOT_NULL_FLAG;	// Because of outer join
    }
    return new_field;
  }
  case Item::FUNC_ITEM:
  case Item::COND_ITEM:
  case Item::FIELD_AVG_ITEM:
  case Item::FIELD_STD_ITEM:
4396
  case Item::SUBSELECT_ITEM:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4397
    /* The following can only happen with 'CREATE TABLE ... SELECT' */
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4398
  case Item::PROC_ITEM:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4399 4400 4401 4402
  case Item::INT_ITEM:
  case Item::REAL_ITEM:
  case Item::STRING_ITEM:
  case Item::REF_ITEM:
4403
  case Item::NULL_ITEM:
4404
  case Item::VARBIN_ITEM:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416
  {
    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,
				 item->name,table,item->decimals);
      break;
    case INT_RESULT:
      new_field=new Field_longlong(item->max_length,maybe_null,
4417
				   item->name,table, item->unsigned_flag);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4418 4419 4420 4421
      break;
    case STRING_RESULT:
      if (item->max_length > 255)
	new_field=  new Field_blob(item->max_length,maybe_null,
4422
				   item->name,table,item->collation.collation);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4423 4424
      else
	new_field= new Field_string(item->max_length,maybe_null,
4425
				    item->name,table,item->collation.collation);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4426
      break;
4427
    case ROW_RESULT: 
4428
    default: 
4429 4430
      // This case should never be choosen
      DBUG_ASSERT(0);
4431
      new_field= 0; // to satisfy compiler (uninitialized variable)
4432
      break;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4433
    }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4434 4435
    if (copy_func && item->is_result_field())
      *((*copy_func)++) = item;			// Save for copy_funcs
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4436
    if (modify_item)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4437
      item->set_result_field(new_field);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4438 4439 4440 4441 4442 4443 4444 4445
    return new_field;
  }
  default:					// Dosen't have to be stored
    return 0;
  }
}


4446 4447 4448 4449 4450 4451 4452
/*
  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
4453 4454 4455
TABLE *
create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
		 ORDER *group, bool distinct, bool save_sum_fields,
4456 4457
		 ulong select_options, ha_rows rows_limit,
		 char *table_alias)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4458 4459 4460
{
  TABLE *table;
  uint	i,field_count,reclength,null_count,null_pack_length,
4461
        hidden_null_count, hidden_null_pack_length, hidden_field_count,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4462 4463
	blob_count,group_null_items;
  bool	using_unique_constraint=0;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4464
  bool  not_all_columns= !(select_options & TMP_TABLE_ALL_COLUMNS);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4465 4466 4467
  char	*tmpname,path[FN_REFLEN];
  byte	*pos,*group_buff;
  uchar *null_flags;
4468
  Field **reg_field, **from_field, **blob_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4469 4470 4471
  Copy_field *copy=0;
  KEY *keyinfo;
  KEY_PART_INFO *key_part_info;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4472
  Item **copy_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4473
  MI_COLUMNDEF *recinfo;
4474
  uint temp_pool_slot=MY_BIT_NONE;
4475

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4476
  DBUG_ENTER("create_tmp_table");
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4477
  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
4478
		      (int) distinct, (int) save_sum_fields,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4479
		      (ulong) rows_limit,test(group)));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4480

4481
  statistic_increment(created_tmp_tables, &LOCK_status);
4482

4483
  if (use_temp_pool)
4484
    temp_pool_slot = bitmap_set_next(&temp_pool);
4485 4486

  if (temp_pool_slot != MY_BIT_NONE) // we got a slot
4487
    sprintf(path, "%s%s_%lx_%i", mysql_tmpdir, tmp_file_prefix,
4488 4489
	    current_pid, temp_pool_slot);
  else // if we run out of slots or we are not using tempool
4490 4491 4492
    sprintf(path,"%s%s%lx_%lx_%x",mysql_tmpdir,tmp_file_prefix,current_pid,
            thd->thread_id, thd->tmp_table++);

bk@work.mysql.com's avatar
bk@work.mysql.com committed
4493 4494 4495 4496 4497
  if (group)
  {
    if (!param->quick_group)
      group=0;					// Can't use group key
    else for (ORDER *tmp=group ; tmp ; tmp=tmp->next)
4498
    {
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4499
      (*tmp->item)->marker=4;			// Store null in key
4500 4501 4502
      if ((*tmp->item)->max_length >= MAX_CHAR_WIDTH)
	using_unique_constraint=1;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4503 4504
    if (param->group_length >= MAX_BLOB_WIDTH)
      using_unique_constraint=1;
4505 4506
    if (group)
      distinct=0;				// Can't use distinct
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4507 4508 4509
  }

  field_count=param->field_count+param->func_count+param->sum_func_count;
4510
  hidden_field_count=param->hidden_field_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4511 4512
  if (!my_multi_malloc(MYF(MY_WME),
		       &table,sizeof(*table),
4513 4514 4515
		       &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
4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526
		       &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))
  {
4527
    bitmap_clear_bit(&temp_pool, temp_pool_slot);
4528
    DBUG_RETURN(NULL);				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4529 4530 4531
  }
  if (!(param->copy_field=copy=new Copy_field[field_count]))
  {
4532
    bitmap_clear_bit(&temp_pool, temp_pool_slot);
4533 4534
    my_free((gptr) table,MYF(0));		/* purecov: inspected */
    DBUG_RETURN(NULL);				/* purecov: inspected */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4535
  }
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4536
  param->items_to_copy= copy_func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4537 4538 4539 4540 4541 4542 4543
  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;
4544
  table->blob_field= (Field_blob**) blob_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4545
  table->real_name=table->path=tmpname;
4546
  table->table_name= table_alias;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4547 4548 4549 4550
  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;
4551
  table->tmp_table= TMP_TABLE;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4552
  table->db_low_byte_first=1;			// True for HEAP and MyISAM
4553
  table->temp_pool_slot = temp_pool_slot;
4554
  table->copy_blobs= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4555

4556
  /* Calculate which type of fields we will store in the temporary table */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4557

4558 4559
  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
4560

monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4561
  List_iterator_fast<Item> li(fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4562 4563
  Item *item;
  Field **tmp_from_field=from_field;
4564
  while ((item=li++))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4565 4566
  {
    Item::Type type=item->type();
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4567
    if (not_all_columns)
4568
    {
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4569 4570 4571 4572 4573 4574 4575 4576 4577 4578
      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;
      }
4579
      if (item->const_item() && (int) hidden_field_count <= 0)
4580
        continue; // We don't have to store this
4581
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4582 4583 4584 4585 4586 4587 4588 4589 4590
    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++)
      {
	Item *arg= ((Item_sum*) item)->args[i];
	if (!arg->const_item())
	{
	  Field *new_field=
4591 4592
	    create_tmp_field(thd, table,arg,arg->type(),&copy_func,
			     tmp_from_field, group != 0,not_all_columns);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4593 4594 4595 4596 4597 4598 4599 4600
	  if (!new_field)
	    goto err;					// Should be OOM
	  tmp_from_field++;
	  *(reg_field++)= new_field;
	  reclength+=new_field->pack_length();
	  if (!(new_field->flags & NOT_NULL_FLAG))
	    null_count++;
	  if (new_field->flags & BLOB_FLAG)
4601 4602
	  {
	    *blob_field++= new_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4603
	    blob_count++;
4604
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4605 4606 4607 4608 4609 4610
	  ((Item_sum*) item)->args[i]= new Item_field(new_field);
	}
      }
    }
    else
    {
4611 4612 4613 4614 4615 4616 4617 4618 4619 4620
      /*
	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.
      */
4621
      Field *new_field=create_tmp_field(thd, table, item,type, &copy_func,
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4622
					tmp_from_field, group != 0,
4623
					not_all_columns || group !=0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4624 4625
      if (!new_field)
      {
4626
	if (thd->is_fatal_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4627 4628 4629 4630 4631 4632 4633 4634 4635 4636
	  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)
4637 4638
      {
	*blob_field++= new_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4639
	blob_count++;
4640
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4641 4642 4643 4644 4645 4646 4647
      if (item->marker == 4 && item->maybe_null)
      {
	group_null_items++;
	new_field->flags|= GROUP_FLAG;
      }
      *(reg_field++) =new_field;
    }
4648 4649
    if (!--hidden_field_count)
      hidden_null_count=null_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4650
  }
4651
  DBUG_ASSERT(field_count >= (uint) (reg_field - table->field));
monty@donna.mysql.com's avatar
monty@donna.mysql.com committed
4652
  field_count= (uint) (reg_field - table->field);
4653
  *blob_field= 0;				// End marker
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4654 4655

  /* If result table is small; use a heap */
4656
  if (blob_count || using_unique_constraint ||
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675
      (select_options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
      OPTION_BIG_TABLES)
  {
    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)
4676 4677
  {
    /* We need to ensure that first byte is not 0 for the delete link */
4678
    if (param->hidden_field_count)
4679 4680 4681 4682 4683 4684 4685
      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
4686 4687 4688 4689 4690 4691 4692 4693
  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;
4694
    if (!(table->record[0]= (byte *) my_malloc(alloc_length*3, MYF(MY_WME))))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4695
      goto err;
4696
    table->record[1]= table->record[0]+alloc_length;
4697
    table->default_values= table->record[1]+alloc_length;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712
  }
  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
  }
  null_count= (blob_count == 0) ? 1 : 0;
4713
  hidden_field_count=param->hidden_field_count;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4714 4715 4716 4717 4718 4719 4720 4721 4722 4723
  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)
      {
4724 4725 4726 4727
	/*
	  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
4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761
	*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
4762
      recinfo->type=FIELD_SKIP_ENDSPACE;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4763 4764
    else
      recinfo->type=FIELD_NORMAL;
4765 4766
    if (!--hidden_field_count)
      null_count=(null_count+7) & ~7;		// move to next byte
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4767 4768
  }

monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
4769
  param->copy_field_end=copy;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4770
  param->recinfo=recinfo;
4771
  store_record(table,default_values);			// Make empty default record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4772

4773
  if (thd->variables.tmp_table_size == ~(ulong) 0)		// No limit
4774 4775 4776
    table->max_rows= ~(ha_rows) 0;
  else
    table->max_rows=(((table->db_type == DB_TYPE_HEAP) ?
4777 4778 4779
		      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
4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795
  set_if_bigger(table->max_rows,1);		// For dummy start options
  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;
4796
    keyinfo->algorithm= HA_KEY_ALG_UNDEF;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4797 4798 4799 4800
    for (; group ; group=group->next,key_part_info++)
    {
      Field *field=(*group->item)->tmp_table_field();
      bool maybe_null=(*group->item)->maybe_null;
4801
      key_part_info->null_bit=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812
      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)
      {
	group->buff=(char*) group_buff;
4813
	if (!(group->field=field->new_field(&thd->mem_root,table)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4814 4815 4816 4817
	  goto err; /* purecov: inspected */
	if (maybe_null)
	{
	  /*
4818 4819 4820 4821
	    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
4822
	  */
4823 4824 4825 4826 4827
	  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]);
	  group->field->move_field((char*) ++group->buff);
4828
	  group_buff++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4829 4830 4831 4832 4833 4834 4835 4836 4837
	}
	else
	  group->field->move_field((char*) group_buff);
	group_buff+= key_part_info->length;
      }
      keyinfo->key_length+=  key_part_info->length;
    }
  }

4838
  if (distinct)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4839
  {
4840 4841 4842 4843 4844 4845
    /*
      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.
    */
4846 4847
    DBUG_PRINT("info",("hidden_field_count: %d", param->hidden_field_count));

4848
    null_pack_length-=hidden_null_pack_length;
4849
    keyinfo->key_parts= ((field_count-param->hidden_field_count)+
4850
			 test(null_pack_length));
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
4851 4852
    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
4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864
    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;
4865
    keyinfo->flags=HA_NOSAME | HA_NULL_ARE_EQUAL;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4866 4867
    keyinfo->key_length=(uint16) reclength;
    keyinfo->name=(char*) "tmp";
4868
    keyinfo->algorithm= HA_KEY_ALG_UNDEF;
4869
    if (null_pack_length)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4870
    {
4871
      key_part_info->null_bit=0;
4872 4873
      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
4874 4875 4876 4877 4878
      key_part_info->field=new Field_string((char*) table->record[0],
					    (uint32) key_part_info->length,
					    (uchar*) 0,
					    (uint) 0,
					    Field::NONE,
4879
					    NullS, table, &my_charset_bin);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4880 4881 4882 4883
      key_part_info->key_type=FIELDFLAG_BINARY;
      key_part_info->type=    HA_KEYTYPE_BINARY;
      key_part_info++;
    }
4884
    /* Create a distinct key over the columns we are going to return */
4885 4886
    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
4887 4888
	 i++, reg_field++, key_part_info++)
    {
4889
      key_part_info->null_bit=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4890 4891 4892 4893 4894 4895 4896 4897 4898 4899
      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;
    }
  }
4900
  if (thd->is_fatal_error)				// If end of memory
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4901 4902 4903 4904 4905 4906 4907
    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;
  }
4908 4909
  /* Set table_name for easier debugging */
  table->table_name= base_name(tmpname);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4910 4911 4912 4913
  if (!open_tmp_table(table))
    DBUG_RETURN(table);

 err:
4914 4915 4916 4917 4918
  /*
    Hack to ensure that free_blobs() doesn't fail if blob_field is not yet
    complete
  */
  *table->blob_field= 0;
4919
  free_tmp_table(thd,table);                    /* purecov: inspected */
4920
  bitmap_clear_bit(&temp_pool, temp_pool_slot);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939
  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,
4940
				    ulong options)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4941 4942 4943 4944 4945 4946 4947 4948 4949 4950
{
  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;
4951
    HA_KEYSEG *seg= (HA_KEYSEG*) sql_calloc(sizeof(*seg) *
bk@work.mysql.com's avatar
bk@work.mysql.com committed
4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986
					    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;
4987
      seg->flag=     0;
4988
      seg->language= field->charset()->number;
4989 4990
      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
4991 4992 4993 4994 4995 4996 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010
      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;
      }
5011
      if (!(field->flags & NOT_NULL_FLAG))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5012 5013 5014
      {
	seg->null_bit= field->null_bit;
	seg->null_pos= (uint) (field->null_ptr - (uchar*) table->record[0]);
5015 5016 5017 5018 5019 5020 5021
	/*
	  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
5022 5023 5024 5025 5026
      }
    }
  }
  MI_CREATE_INFO create_info;
  bzero((char*) &create_info,sizeof(create_info));
5027

5028 5029
  if ((options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
      OPTION_BIG_TABLES)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042
    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;
  }
5043
  statistic_increment(created_tmp_disk_tables, &LOCK_status);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059
  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";
5060
  free_blobs(entry);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5061 5062 5063 5064 5065 5066 5067 5068 5069
  if (entry->db_stat && entry->file)
  {
    (void) entry->file->close();
    delete entry->file;
  }
  if (!(test_flags & TEST_KEEP_TMP_TABLES) || entry->db_type == DB_TYPE_HEAP)
    (void) ha_delete_table(entry->db_type,entry->real_name);
  /* free blobs */
  for (Field **ptr=entry->field ; *ptr ; ptr++)
5070
    (*ptr)->free();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5071 5072
  my_free((gptr) entry->record[0],MYF(0));
  free_io_cache(entry);
5073

5074
  bitmap_clear_bit(&temp_pool, entry->temp_pool_slot);
5075

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5076 5077 5078 5079 5080 5081 5082 5083 5084 5085
  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
5086 5087
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
5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107
{
  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,
5108
			      thd->lex.select_lex.options | thd->options))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5109 5110 5111 5112 5113
    goto err2;
  if (open_tmp_table(&new_table))
    goto err1;
  table->file->index_end();
  table->file->rnd_init();
5114 5115
  if (table->no_rows)
  {
5116 5117
    new_table.file->extra(HA_EXTRA_NO_ROWS);
    new_table.no_rows=1;
5118 5119
  }

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141
  /* 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 */
  (void) table->file->rnd_end();
  (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);
5142 5143
  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
5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159
  DBUG_RETURN(0);

 err:
  DBUG_PRINT("error",("Got error: %d",write_err));
  table->file->print_error(error,MYF(0));	// Give table is full error
  (void) table->file->rnd_end();
  (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);
}


5160 5161 5162 5163 5164 5165
/****************************************************************************
  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
5166 5167 5168 5169

static int
do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
{
5170
  int error= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5171 5172 5173 5174 5175 5176
  JOIN_TAB *join_tab;
  int (*end_select)(JOIN *, struct st_join_table *,bool);
  DBUG_ENTER("do_select");

  join->procedure=procedure;
  /*
5177
    Tell the client how many fields there are in a row
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5178 5179 5180 5181 5182 5183 5184 5185
  */
  if (!table)
    join->result->send_fields(*fields,1);
  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
5186
  join->tmp_table= table;			/* Save for easy recursion */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5187 5188 5189 5190 5191 5192 5193 5194 5195
  join->fields= fields;

  /* Set up select_end */
  if (table)
  {
    if (table->group && join->tmp_table_param.sum_func_count)
    {
      if (table->keys)
      {
5196
	DBUG_PRINT("info",("Using end_update"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5197 5198 5199 5200
	end_select=end_update;
	table->file->index_init(0);
      }
      else
5201 5202
      {
	DBUG_PRINT("info",("Using end_unique_update"));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5203
	end_select=end_unique_update;
5204
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230
    }
    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;
  }
  join->join_tab[join->tables-1].next_select=end_select;

  join_tab=join->join_tab+join->const_tables;
  join->send_records=0;
  if (join->tables == join->const_tables)
  {
5231 5232 5233
    if (!join->select_lex->dependent ||
	((!join->conds || join->conds->val_int()) &&
	 (!join->having || join->having->val_int())))
5234
    {
5235 5236
      if (!(error=(*end_select)(join,join_tab,0)) || error == -3)
	error=(*end_select)(join,join_tab,1);
5237
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5238 5239 5240
  }
  else
  {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5241
    error= sub_select(join,join_tab,0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5242
    if (error >= 0)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5243
      error= sub_select(join,join_tab,1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5244
    if (error == -3)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5245
      error= 0;					/* select_limit used */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5246
  }
5247

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5248
  if (error >= 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5249
  {
5250 5251
    error=0;
    if (!table)					// If sending data to client
5252
    {
5253
      /*
5254 5255
	The following will unlock all cursors if the command wasn't an
	update command
5256
      */
5257
      join_free(join, 0);				// Unlock all cursors
5258
      if (join->result->send_eof())
5259
	error= 1;				// Don't send error
5260
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5261 5262 5263 5264
    DBUG_PRINT("info",("%ld records output",join->send_records));
  }
  if (table)
  {
5265
    int tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5266 5267
    if ((tmp=table->file->extra(HA_EXTRA_NO_CACHE)))
    {
5268 5269
      DBUG_PRINT("error",("extra(HA_EXTRA_NO_CACHE) failed"));
      my_errno= tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5270 5271
      error= -1;
    }
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
5272
    if ((tmp=table->file->index_end()))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5273
    {
5274 5275
      DBUG_PRINT("error",("index_end() failed"));
      my_errno= tmp;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5276 5277
      error= -1;
    }
5278
    if (error == -1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5279 5280
      table->file->print_error(my_errno,MYF(0));
  }
5281 5282 5283 5284 5285 5286
#ifndef DBUG_OFF
  if (error)
  {
    DBUG_PRINT("error",("Error: do_select() failed"));
  }
#endif
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5287
  DBUG_RETURN(error || join->thd->net.report_error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301
}


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);
  }
5302 5303 5304 5305 5306
  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
5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333
  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;

  if (!(error=(*join_tab->read_first_record)(join_tab)))
  {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
5334 5335 5336
    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
5337 5338
    READ_RECORD *info= &join_tab->read_record;

5339
    join->thd->row_count= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5340 5341 5342 5343 5344 5345 5346
    do
    {
      if (join->thd->killed)			// Aborted by user
      {
	my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
	return -2;				/* purecov: inspected */
      }
5347
      join->examined_rows++;
5348
      join->thd->row_count++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5349 5350 5351 5352 5353 5354 5355
      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())
	{
5356
	  if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5357
	    return error;
5358 5359 5360 5361 5362
	  /*
	    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
5363 5364
	  if (not_used_in_distinct && found_records != join->found_records)
	    return 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5365
	}
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
5366 5367
	else
	  info->file->unlock_row();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5368 5369 5370
      }
    } while (!(error=info->read_record(info)));
  }
5371
  if (error > 0)				// Fatal error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5372 5373 5374 5375
    return -1;

  if (!found && on_expr)
  {						// OUTER JOIN
5376
    restore_record(join_tab->table,default_values);		// Make empty record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5377 5378 5379
    mark_as_null_row(join_tab->table);		// For group by without error
    if (!select_cond || select_cond->val_int())
    {
5380
      if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456
	return error;				/* purecov: inspected */
    }
  }
  return 0;
}


static int
flush_cached_records(JOIN *join,JOIN_TAB *join_tab,bool skipp_last)
{
  int error;
  READ_RECORD *info;

  if (!join_tab->cache.records)
    return 0;				/* Nothing to do */
  if (skipp_last)
    (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)))
  {
    reset_cache(&join_tab->cache);
    join_tab->cache.records=0; join_tab->cache.ptr_record= (uint) ~0;
    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 ||
		   !join_tab->cache.select->skipp_record()))
    {
      uint i;
      reset_cache(&join_tab->cache);
      for (i=(join_tab->cache.records- (skipp_last ? 1 : 0)) ; i-- > 0 ;)
      {
	read_cached_record(join_tab);
	if (!select || !select->skipp_record())
	  if ((error=(join_tab->next_select)(join,join_tab+1,0)) < 0)
	    return error; /* purecov: inspected */
      }
    }
  } while (!(error=info->read_record(info)));

  if (skipp_last)
    read_cached_record(join_tab);		// Restore current record
  reset_cache(&join_tab->cache);
  join_tab->cache.records=0; join_tab->cache.ptr_record= (uint) ~0;
  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;
}


/*****************************************************************************
5457 5458
  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
5459
*****************************************************************************/
5460 5461 5462

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

5463
int report_error(TABLE *table, int error)
5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481
{
  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;
}


5482
int safe_index_read(JOIN_TAB *tab)
5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493
{
  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
5494
static int
5495
join_read_const_table(JOIN_TAB *tab, POSITION *pos)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5496 5497
{
  int error;
5498 5499 5500 5501 5502 5503 5504
  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
5505
  {
5506 5507 5508 5509 5510 5511 5512
    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
5513
    }
5514 5515 5516 5517
  }
  else
  {
    if ((error=join_read_const(tab)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5518
    {
5519 5520 5521 5522 5523
      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
5524 5525
    }
  }
5526 5527 5528 5529 5530 5531 5532
  if (tab->on_expr && !table->null_row)
  {
    if ((table->null_row= test(tab->on_expr->val_int() == 0)))
      empty_record(table);
    }
  if (!table->null_row)
    table->maybe_null=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543
  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
  {
5544 5545
    if ((error=table->file->read_first_row(table->record[0],
					   table->primary_key)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5546 5547
    {
      if (error != HA_ERR_END_OF_FILE)
5548
	return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5549 5550 5551 5552
      table->null_row=1;			// This is ok.
      empty_record(table);			// Make empty record
      return -1;
    }
5553
    store_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5554 5555
  }
  else if (!table->status)			// Only happens with left join
5556
    restore_record(table,record[1]);			// restore old record
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581
  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
  {
    if (cp_buffer_from_ref(&tab->ref))
      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)
    {
      table->null_row=1;
      empty_record(table);
      if (error != HA_ERR_KEY_NOT_FOUND)
5582
	return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5583 5584
      return -1;
    }
5585
    store_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5586
  }
5587 5588 5589
  else if (!(table->status & ~STATUS_NULL_ROW))	// Only happens with left join
  {
    table->status=0;
5590
    restore_record(table,record[1]);			// restore old record
5591
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603
  table->null_row=0;
  return table->status ? -1 : 0;
}


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

  if (cmp_buffer_with_ref(tab) ||
5604
      (table->status & (STATUS_GARBAGE | STATUS_NO_PARENT | STATUS_NULL_ROW)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5605 5606 5607 5608 5609 5610 5611 5612 5613 5614
  {
    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)
5615
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5616
  }
5617
  table->null_row=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634
  return table->status ? -1 : 0;
}


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

  if (cp_buffer_from_ref(&tab->ref))
    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)
5635
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5636 5637 5638 5639 5640
    return -1; /* purecov: inspected */
  }
  return 0;
}

5641

5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659
/*
  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;

  if (cp_buffer_from_ref(&tab->ref))
    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)
5660
      return report_error(table, error);
5661 5662 5663 5664 5665
    return -1; /* purecov: inspected */
  }
  return 0;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5666 5667 5668 5669 5670 5671 5672 5673 5674 5675

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


static int
5676
join_read_next_same(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5677 5678 5679 5680 5681 5682 5683 5684 5685 5686
{
  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)
5687
      return report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5688 5689 5690 5691 5692 5693
    table->status= STATUS_GARBAGE;
    return -1;
  }
  return 0;
}

5694

5695 5696 5697 5698 5699 5700 5701 5702
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])))
5703 5704 5705
    return report_error(table, error);
  if (key_cmp(table, tab->ref.key_buff, tab->ref.key,
	      tab->ref.key_length))
5706 5707
  {
    table->status=STATUS_NOT_FOUND;
5708
    error= -1;
5709 5710 5711 5712
  }
  return error;
}

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736

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;
  return tab->select->test_quick_select(tab->keys,(table_map) 0,HA_POS_ERROR);
}


static int
join_init_read_record(JOIN_TAB *tab)
{
  if (tab->select && tab->select->quick)
    tab->select->quick->reset();
5737 5738
  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
5739 5740 5741
  return (*tab->read_record.read_record)(&tab->read_record);
}

5742

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5743
static int
5744
join_read_first(JOIN_TAB *tab)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5745 5746 5747
{
  int error;
  TABLE *table=tab->table;
5748 5749
  if (!table->key_read && (table->used_keys & ((key_map) 1 << tab->index)) &&
      !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5750 5751 5752 5753 5754
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
5755
  tab->read_record.read_record=join_read_next;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5756 5757 5758 5759
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
5760
  if ((error=tab->table->file->index_first(tab->table->record[0])))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5761 5762
  {
    if (error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE)
5763
      report_error(table, error);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5764 5765 5766 5767 5768
    return -1;
  }
  return 0;
}

5769

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5770
static int
5771
join_read_next(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5772
{
5773 5774 5775
  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
5776 5777 5778
  return 0;
}

5779

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5780
static int
5781
join_read_last(JOIN_TAB *tab)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5782 5783 5784
{
  TABLE *table=tab->table;
  int error;
5785 5786
  if (!table->key_read && (table->used_keys & ((key_map) 1 << tab->index)) &&
      !table->no_keyread)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5787 5788 5789 5790 5791
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
5792
  tab->read_record.read_record=join_read_prev;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5793 5794 5795 5796
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
5797 5798
  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
5799 5800 5801
  return 0;
}

5802

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5803
static int
5804
join_read_prev(READ_RECORD *info)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5805
{
5806 5807 5808
  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
5809 5810 5811
  return 0;
}

5812

bk@work.mysql.com's avatar
bk@work.mysql.com committed
5813 5814 5815 5816 5817 5818
static int
join_ft_read_first(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
5819
#if NOT_USED_YET
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5820
  if (cp_buffer_from_ref(&tab->ref))       // as ft-key doesn't use store_key's
5821
    return -1;                             // see also FT_SELECT::init()
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5822
#endif
5823
  table->file->ft_init();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5824

5825 5826
  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
5827 5828 5829 5830 5831 5832
  return 0;
}

static int
join_ft_read_next(READ_RECORD *info)
{
5833 5834 5835
  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
5836 5837 5838 5839
  return 0;
}


5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875
/*
  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 */
  *tab->null_ref_key=0;
  if ((res= join_read_always_key(tab)) >= 0)
    return res;

  /* Then read key with null value */
  *tab->null_ref_key= 1;
  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 */
  if (*tab->null_ref_key)
    return -1;					// All keys read
  *tab->null_ref_key= 1;			// Read null key
  return safe_index_read(tab);
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
5876
/*****************************************************************************
5877 5878 5879
  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
5880 5881
*****************************************************************************/

5882
/* ARGSUSED */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5883 5884 5885 5886 5887 5888 5889 5890
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;
5891
    if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5892
      DBUG_RETURN(0);				// Didn't match having
5893
    error=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5894 5895
    if (join->procedure)
      error=join->procedure->send_row(*join->fields);
5896
    else if (join->do_send_rows)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5897 5898 5899
      error=join->result->send_data(*join->fields);
    if (error)
      DBUG_RETURN(-1); /* purecov: inspected */
5900
    if (++join->send_records >= join->unit->select_limit_cnt &&
5901
	join->do_send_rows)
5902 5903 5904
    {
      if (join->select_options & OPTION_FOUND_ROWS)
      {
5905
	JOIN_TAB *jt=join->join_tab;
5906
	if ((join->tables == 1) && !join->tmp_table && !join->sort_and_group
5907
	    && !join->send_group_parts && !join->having && !jt->select_cond &&
5908
	    !(jt->select && jt->select->quick) &&
5909
	    !(jt->table->file->table_flags() & HA_NOT_EXACT_COUNT))
5910
	{
5911
	  /* Join over all rows in table;  Return number of found rows */
5912 5913
	  TABLE *table=jt->table;

5914
	  join->select_options ^= OPTION_FOUND_ROWS;
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
5915 5916
	  if (table->sort.record_pointers ||
	      (table->sort.io_cache && my_b_inited(table->sort.io_cache)))
5917 5918
	  {
	    /* Using filesort */
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
5919
	    join->send_records= table->sort.found_records;
5920 5921 5922 5923 5924 5925
	  }
	  else
	  {
	    table->file->info(HA_STATUS_VARIABLE);
	    join->send_records = table->file->records;
	  }
5926 5927 5928
	}
	else 
	{
5929
	  join->do_send_rows= 0;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
5930 5931
	  if (join->unit->fake_select_lex)
	    join->unit->fake_select_lex->select_limit= HA_POS_ERROR;
5932 5933
	  DBUG_RETURN(0);
	}
5934
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5935
      DBUG_RETURN(-3);				// Abort nicely
5936
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5937 5938 5939 5940 5941 5942 5943 5944 5945 5946 5947 5948 5949 5950 5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961 5962 5963
  }
  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)
  {
    if (join->first_record || (end_of_records && !join->group))
    {
      if (join->procedure)
	join->procedure->end_group();
      if (idx < (int) join->send_group_parts)
      {
5964
	int error=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5965 5966
	if (join->procedure)
	{
5967
	  if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5968
	    error= -1;				// Didn't satisfy having
5969 5970 5971 5972 5973 5974
 	  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
5975 5976 5977 5978 5979 5980
	  if (end_of_records && join->procedure->end_of_records())
	    error= 1;				// Fatal error
	}
	else
	{
	  if (!join->first_record)
5981 5982
	  {
	    /* No matching rows for group function */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5983
	    clear_tables(join);
5984 5985
	    copy_fields(&join->tmp_table_param);
	  }
5986
	  if (join->having && join->having->val_int() == 0)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
5987
	    error= -1;				// Didn't satisfy having
5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998
	  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
5999 6000 6001
	}
	if (error > 0)
	  DBUG_RETURN(-1);			/* purecov: inspected */
6002 6003
	if (end_of_records)
	  DBUG_RETURN(0);
6004
	if (join->send_records >= join->unit->select_limit_cnt &&
6005 6006 6007 6008 6009
	    join->do_send_rows)
	{
	  if (!(join->select_options & OPTION_FOUND_ROWS))
	    DBUG_RETURN(-3);				// Abort nicely
	  join->do_send_rows=0;
6010
	  join->unit->select_limit_cnt = HA_POS_ERROR;
6011
        }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022 6023
      }
    }
    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);
6024 6025
      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
6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045 6046 6047 6048 6049 6050 6051 6052 6053 6054 6055
      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
6056
    copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6057

6058
#ifdef TO_BE_DELETED
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6059 6060 6061 6062 6063 6064 6065 6066 6067 6068
    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)
	{
	  Field *field=item->tmp_table_field();
6069
	  field->ptr[-1]= (byte) (field->is_null() ? 1 : 0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6070 6071 6072
	}
      }
    }
6073
#endif
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6074 6075
    if (!join->having || join->having->val_int())
    {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6076
      join->found_records++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6077 6078
      if ((error=table->file->write_row(table->record[0])))
      {
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6079 6080 6081
	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
6082 6083
	if (create_myisam_from_heap(join->thd, table, &join->tmp_table_param,
				    error,1))
6084
	  DBUG_RETURN(-1);			// Not a table_is_full error
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6085
	table->uniques=0;			// To ensure rows are the same
6086
      }
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6087
      if (++join->send_records >= join->tmp_table_param.end_write_records &&
6088 6089 6090 6091 6092
	  join->do_send_rows)
      {
	if (!(join->select_options & OPTION_FOUND_ROWS))
	  DBUG_RETURN(-3);
	join->do_send_rows=0;
6093
	join->unit->select_limit_cnt = HA_POS_ERROR;
6094
	DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6095 6096 6097
      }
    }
  }
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
6098
end:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6099 6100 6101 6102 6103 6104 6105 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116 6117 6118 6119 6120 6121
  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
6122
  join->found_records++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6123 6124 6125 6126 6127 6128
  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
6129 6130 6131
#ifdef EMBEDDED_LIBRARY
    join->thd->net.last_errno= 0;
#endif
6132
    /* Store in the used key if the field was 0 */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6133
    if (item->maybe_null)
6134
      group->buff[-1]=item->null_value ? 1 : 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6135 6136 6137 6138 6139 6140
  }
  // table->file->index_init(0);
  if (!table->file->index_read(table->record[1],
			       join->tmp_table_param.group_buff,0,
			       HA_READ_KEY_EXACT))
  {						/* Update old record */
6141
    restore_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6142 6143 6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159
    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
6160
  copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6161 6162
  if ((error=table->file->write_row(table->record[0])))
  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
6163 6164
    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
6165 6166 6167 6168 6169 6170 6171 6172 6173 6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 6191 6192 6193
      DBUG_RETURN(-1);				// Not a table_is_full error
    /* Change method to update rows */
    table->file->index_init(0);
    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
6194
  copy_funcs(join->tmp_table_param.items_to_copy);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 6205 6206 6207 6208 6209

  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 */
    }
6210
    restore_record(table,record[1]);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247
    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();
      if (idx < (int) join->send_group_parts)
      {
	if (!join->first_record)
6248 6249
	{
	  /* No matching rows for group function */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6250
	  clear_tables(join);
6251 6252
	  copy_fields(&join->tmp_table_param);
	}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6253 6254 6255 6256 6257
	copy_sum_funcs(join->sum_funcs);
	if (!join->having || join->having->val_int())
	{
	  if ((error=table->file->write_row(table->record[0])))
	  {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
6258
	    if (create_myisam_from_heap(join->thd, table,
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
6259
					&join->tmp_table_param,
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6260
					error, 0))
6261
	      DBUG_RETURN(-1);			// Not a table_is_full error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6262 6263 6264 6265 6266 6267 6268 6269 6270 6271
	  }
	  else
	    join->send_records++;
	}
	if (end_of_records)
	  DBUG_RETURN(0);
      }
    }
    else
    {
6272 6273
      if (end_of_records)
	DBUG_RETURN(0);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6274 6275 6276 6277 6278 6279
      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
6280
      copy_funcs(join->tmp_table_param.items_to_copy);
6281 6282
      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
6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293 6294 6295 6296
      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);
}


/*****************************************************************************
6297 6298 6299 6300 6301
  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
6302 6303 6304 6305 6306 6307 6308
*****************************************************************************/

/* 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;
6309 6310
  // 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
6311 6312
  {
    Item *ref_item=part_of_refkey(field->table,field);
6313
    if (ref_item && ref_item->eq(right_item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6314 6315
    {
      if (right_item->type() == Item::FIELD_ITEM)
6316 6317
	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
6318
      {
6319 6320 6321 6322
	/*
	  We can remove binary fields and numerical fields except float,
	  as float comparison isn't 100 % secure
	*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343
	if (field->binary() &&
	    (field->type() != FIELD_TYPE_FLOAT || field->decimals() == 0))
	{
	  return !store_val_in_field(field,right_item);
	}
      }
    }
  }
  return 0;					// keep test
}


static COND *
make_cond_for_table(COND *cond,table_map tables,table_map used_table)
{
  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)
    {
6344
      /* Create new top level AND item */
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6345 6346 6347 6348 6349 6350 6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381
      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:
	new_cond->used_tables_cache=((Item_cond*) cond)->used_tables_cache &
	  tables;
	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);
      }
      new_cond->used_tables_cache=((Item_cond_or*) cond)->used_tables_cache;
6382
      new_cond->top_level_item();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6383 6384 6385 6386 6387
      return new_cond;
    }
  }

  /*
6388 6389 6390
    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
6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404 6405 6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420 6421
  */

  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)
{
6422 6423 6424
  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
6425 6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440
  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) &&
	  !(key_part->key_part_flag & HA_PART_KEY))
	return table->reginfo.join_tab->ref.items[part];
  }
  return (Item*) 0;
}


/*****************************************************************************
6441 6442 6443 6444 6445
  Test if one can use the key to resolve ORDER BY
  Returns: 1 if key is ok.
	   0 if key can't be used
	  -1 if reverse key can be used
          used_key_parts is set to key parts used if length != 0
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6446 6447
*****************************************************************************/

6448 6449
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
6450 6451 6452 6453 6454 6455 6456 6457 6458 6459 6460 6461 6462 6463 6464 6465 6466 6467 6468 6469 6470 6471 6472 6473 6474 6475 6476 6477 6478 6479 6480
{
  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;

  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()
    */
    while (const_key_parts & 1)
    {
      key_part++; const_key_parts>>=1;
    }
    if (key_part == key_part_end || key_part->field != field)
      return 0;

    /* set flag to 1 if we can use read-next on key, else to -1 */
    flag=(order->asc == !(key_part->key_part_flag & HA_REVERSE_SORT))
      ? 1 : -1;
    if (reverse && flag != reverse)
      return 0;
    reverse=flag;				// Remember if reverse
    key_part++;
  }
6481
  *used_key_parts= (uint) (key_part - table->key_info[idx].key_part);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6482 6483 6484 6485 6486 6487 6488 6489 6490 6491 6492 6493 6494 6495 6496 6497 6498 6499 6500 6501 6502
  return reverse;
}

static uint find_shortest_key(TABLE *table, key_map usable_keys)
{
  uint min_length= (uint) ~0;
  uint best= MAX_KEY;
  for (uint nr=0; usable_keys ; usable_keys>>=1, nr++)
  {
    if (usable_keys & 1)
    {
      if (table->key_info[nr].key_length < min_length)
      {
	min_length=table->key_info[nr].key_length;
	best=nr;
      }
    }
  }
  return best;
}

6503 6504 6505 6506 6507 6508 6509 6510 6511 6512 6513 6514 6515 6516 6517 6518 6519 6520 6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532 6533 6534 6535 6536 6537 6538 6539 6540
/*
  SYNOPSIS
    is_subkey()
    key_part		- first key parts
    ref_key_part	- second key parts
    ref_key_part_end	- last+1 part of the second key
  DESCRIPTION
    Test if a second key is the subkey of the first one.
  NOTE
    Second key MUST be shorter than the first one.
  RETURN
    1	- is the subkey
    0	- otherwise
*/

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;
}

/*
  SYNOPSIS
    test_if_subkey()
    ref		- number of key, used for WHERE clause
    usable_keys - keys for testing
  DESCRIPTION
    Test if we can use one of the 'usable_keys' instead of 'ref' key.
  RETURN
    MAX_KEY			- if we can't use other key
    the number of found key	- otherwise
*/

static uint
6541 6542
test_if_subkey(ORDER *order, TABLE *table, uint ref, uint ref_key_parts,
	       key_map usable_keys)
6543 6544 6545 6546 6547 6548 6549 6550 6551 6552 6553 6554 6555 6556 6557 6558 6559 6560 6561 6562 6563 6564 6565
{
  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;
  
  for (nr= 0; usable_keys; usable_keys>>= 1, nr++)
  {
    if ((usable_keys & 1) &&
	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
6566

6567 6568 6569 6570 6571 6572 6573 6574 6575 6576
/*
  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
6577 6578

static bool
6579 6580
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
6581 6582
{
  int ref_key;
6583
  uint ref_key_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6584 6585 6586 6587
  TABLE *table=tab->table;
  SQL_SELECT *select=tab->select;
  key_map usable_keys;
  DBUG_ENTER("test_if_skip_sort_order");
6588
  LINT_INIT(ref_key_parts);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6589 6590 6591 6592 6593 6594 6595 6596 6597 6598

  /* Check which keys can be used to resolve ORDER BY */
  usable_keys= ~(key_map) 0;
  for (ORDER *tmp_order=order; tmp_order ; tmp_order=tmp_order->next)
  {
    if ((*tmp_order->item)->type() != Item::FIELD_ITEM)
    {
      usable_keys=0;
      break;
    }
6599
    usable_keys&=((Item_field*) (*tmp_order->item))->field->part_of_sortkey;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6600 6601 6602
  }

  ref_key= -1;
6603 6604
  /* Test if constant range in WHERE */
  if (tab->ref.key >= 0)
6605 6606 6607
  {
    ref_key=	   tab->ref.key;
    ref_key_parts= tab->ref.key_parts;
6608 6609
    if (tab->type == JT_REF_OR_NULL)
      DBUG_RETURN(0);
6610
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6611
  else if (select && select->quick)		// Range found by opt_range
6612 6613 6614 6615
  {
    ref_key=	   select->quick->index;
    ref_key_parts= select->quick->used_key_parts;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6616 6617 6618

  if (ref_key >= 0)
  {
6619 6620 6621
    /*
      We come here when there is a REF key.
    */
6622
    int order_direction;
6623
    uint used_key_parts;
6624 6625 6626 6627 6628
    if (!(usable_keys & ((key_map) 1 << ref_key)))
    {
      /*
	We come here when ref_key is not among usable_keys
      */
6629 6630 6631 6632 6633 6634 6635 6636 6637
      uint new_ref_key;
      /*
	If using index only read, only consider other possible index only
	keys
      */
      if (table->used_keys & (((key_map) 1 << ref_key)))
	usable_keys|= table->used_keys;
      if ((new_ref_key= test_if_subkey(order, table, ref_key, ref_key_parts,
				       usable_keys)) < MAX_KEY)
6638
      {
6639
	/* Found key that can be used to retrieve data in sorted order */
6640 6641
	if (tab->ref.key >= 0)
	{
6642 6643
	  tab->ref.key= new_ref_key;
	  table->file->index_init(new_ref_key);
6644 6645 6646
	}
	else
	{
6647
	  select->quick->index= new_ref_key;
6648 6649
	  select->quick->init();
	}
6650
	ref_key= new_ref_key;
6651 6652
      }  
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6653 6654
    /* Check if we get the rows in requested sorted order by using the key */
    if ((usable_keys & ((key_map) 1 << ref_key)) &&
6655 6656
	(order_direction = test_if_order_by_key(order,table,ref_key,
						&used_key_parts)))
6657
    {
6658
      if (order_direction == -1)		// If ORDER BY ... DESC
6659
      {
6660 6661
	if (select && select->quick)
	{
6662 6663 6664 6665 6666
	  /*
	    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())
6667
	  {
6668 6669
            if (table->file->index_flags(ref_key) & HA_NOT_READ_PREFIX_LAST)
              DBUG_RETURN(0);			// Use filesort
6670 6671 6672 6673 6674 6675 6676 6677 6678
	    // 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;
6679 6680 6681 6682 6683 6684 6685
	  }
	  DBUG_RETURN(1);
	}
	if (tab->ref.key_parts < used_key_parts)
	{
	  /*
	    SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
6686 6687 6688

	    Use a traversal function that starts by reading the last row
	    with key part (A) and then traverse the index backwards.
6689
	  */
6690
	  if (table->file->index_flags(ref_key) & HA_NOT_READ_PREFIX_LAST)
6691
	    DBUG_RETURN(0);			// Use filesort
6692 6693 6694
	  tab->read_first_record=       join_read_last_key;
	  tab->read_record.read_record= join_read_prev_same;
	  /* fall through */
6695
	}
6696
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6697
      DBUG_RETURN(1);			/* No need to sort */
6698
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6699 6700 6701 6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712
  }
  else
  {
    /* check if we can use a key to resolve the group */
    /* Tables using JT_NEXT are handled here */
    uint nr;
    key_map keys=usable_keys;

    /*
      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)
6713
      keys&= (table->used_keys | table->file->keys_to_use_for_scanning());
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6714 6715 6716

    for (nr=0; keys ; keys>>=1, nr++)
    {
6717
      uint not_used;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6718 6719 6720
      if (keys & 1)
      {
	int flag;
6721
	if ((flag=test_if_order_by_key(order, table, nr, &not_used)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6722
	{
6723 6724 6725
	  if (!no_changes)
	  {
	    tab->index=nr;
6726 6727
	    tab->read_first_record=  (flag > 0 ? join_read_first:
				      join_read_last);
6728 6729
	    table->file->index_init(nr);
	    tab->type=JT_NEXT;	// Read with index_first(), index_next()
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6730 6731 6732 6733 6734
	    if (table->used_keys & ((key_map) 1 << nr))
	    {
	      table->key_read=1;
	      table->file->extra(HA_EXTRA_KEYREAD);
	    }
6735
	  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6736 6737 6738 6739 6740 6741 6742 6743
	  DBUG_RETURN(1);
	}
      }
    }
  }
  DBUG_RETURN(0);				// Can't use index.
}

6744

monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
6745
/*
6746
  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
6747 6748 6749 6750 6751 6752 6753 6754 6755 6756 6757 6758 6759 6760 6761 6762 6763 6764 6765 6766 6767 6768 6769 6770

  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
		        Used to decide if we should use index or not     


  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
*/
6771

bk@work.mysql.com's avatar
bk@work.mysql.com committed
6772
static int
monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6773 6774
create_sort_index(THD *thd, JOIN_TAB *tab, ORDER *order,
		  ha_rows filesort_limit, ha_rows select_limit)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6775 6776 6777
{
  SORT_FIELD *sortorder;
  uint length;
6778
  ha_rows examined_rows;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6779 6780 6781 6782
  TABLE *table=tab->table;
  SQL_SELECT *select=tab->select;
  DBUG_ENTER("create_sort_index");

6783
  if (test_if_skip_sort_order(tab,order,select_limit,0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6784 6785 6786 6787
    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
6788 6789
  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
6790 6791 6792 6793 6794 6795 6796 6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809 6810
  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.
6811 6812
	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
6813
      */
6814
      if (!(select->quick=get_ft_or_quick_select_for_ref(table, tab)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6815 6816 6817
	goto err;
    }
  }
6818 6819
  if (table->tmp_table)
    table->file->info(HA_STATUS_VARIABLE);	// Get record count
igor@hundin.mysql.fi's avatar
igor@hundin.mysql.fi committed
6820 6821 6822
  table->sort.found_records=filesort(thd, table,sortorder, length,
                                     select, filesort_limit, &examined_rows);
  tab->records=table->sort.found_records;		// For SQL_CALC_ROWS
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6823 6824 6825 6826 6827
  delete select;				// filesort did select
  tab->select=0;
  tab->select_cond=0;
  tab->type=JT_ALL;				// Read with normal read_record
  tab->read_first_record= join_init_read_record;
6828
  tab->join->examined_rows+=examined_rows;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6829 6830 6831 6832 6833
  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
6834
  DBUG_RETURN(table->sort.found_records == HA_POS_ERROR);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6835 6836 6837 6838
err:
  DBUG_RETURN(-1);
}

6839
/*
6840
  Add the HAVING criteria to table->select
6841 6842
*/

monty@hundin.mysql.fi's avatar
monty@hundin.mysql.fi committed
6843
#ifdef NOT_YET
6844 6845 6846 6847 6848 6849
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
6850
  DBUG_EXECUTE("where",print_where(*having,"having"););
6851 6852 6853 6854 6855 6856 6857 6858 6859 6860 6861 6862 6863
  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
      if (!(table->select->cond=new Item_cond_and(table->select->cond,
						  sort_table_cond)))
	return 1;
    table->select_cond=table->select->cond;
6864
    table->select_cond->top_level_item();
6865 6866 6867 6868 6869 6870 6871
    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
6872
#endif
6873 6874


bk@work.mysql.com's avatar
bk@work.mysql.com committed
6875
/*****************************************************************************
6876 6877 6878 6879 6880
  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
6881 6882 6883 6884 6885 6886 6887 6888 6889 6890 6891 6892 6893 6894 6895 6896 6897 6898 6899 6900 6901 6902 6903 6904 6905 6906 6907 6908 6909 6910 6911 6912 6913 6914
*****************************************************************************/

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
6915
remove_duplicates(JOIN *join, TABLE *entry,List<Item> &fields, Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6916 6917 6918 6919
{
  int error;
  ulong reclength,offset;
  uint field_count;
6920
  THD *thd= join->thd;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6921 6922 6923 6924 6925 6926 6927 6928 6929
  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++))
6930 6931
  {
    if (item->tmp_table_field() && ! item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6932
      field_count++;
6933
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6934 6935 6936

  if (!field_count)
  {						// only const items
6937
    join->unit->select_limit_cnt= 1;		// Only send first row
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6938 6939 6940 6941 6942 6943 6944 6945 6946 6947 6948
    DBUG_RETURN(0);
  }
  Field **first_field=entry->field+entry->fields - field_count;
  offset=entry->field[entry->fields - field_count]->offset();
  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 &&
       ((ALIGN_SIZE(reclength) +sizeof(HASH_LINK)) * entry->file->records <
6949
	thd->variables.sortbuff_size)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6950 6951
    error=remove_dup_with_hash_index(join->thd, entry,
				     field_count, first_field,
6952
				     reclength, having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6953
  else
6954 6955
    error=remove_dup_with_compare(join->thd, entry, first_field, offset,
				  having);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6956 6957 6958 6959 6960 6961 6962

  free_blobs(first_field);
  DBUG_RETURN(error);
}


static int remove_dup_with_compare(THD *thd, TABLE *table, Field **first_field,
6963
				   ulong offset, Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6964 6965 6966
{
  handler *file=table->file;
  char *org_record,*new_record;
monty@donna.mysql.fi's avatar
monty@donna.mysql.fi committed
6967
  byte *record;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6968 6969 6970 6971
  int error;
  ulong reclength=table->reclength-offset;
  DBUG_ENTER("remove_dup_with_compare");

6972
  org_record=(char*) (record=table->record[0])+offset;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6973 6974 6975
  new_record=(char*) table->record[1]+offset;

  file->rnd_init();
6976
  error=file->rnd_next(record);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
6977 6978 6979 6980 6981 6982 6983 6984 6985 6986 6987 6988 6989 6990 6991 6992
  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;
    }
6993 6994 6995 6996
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
6997
      error=file->rnd_next(record);
6998 6999
      continue;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7000 7001
    if (copy_blobs(first_field))
    {
serg@serg.mysql.com's avatar
serg@serg.mysql.com committed
7002
      my_error(ER_OUTOFMEMORY,MYF(0));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7003 7004 7005 7006 7007 7008 7009 7010 7011
      error=0;
      goto err;
    }
    memcpy(new_record,org_record,reclength);

    /* Read through rest of file and mark duplicated rows deleted */
    bool found=0;
    for (;;)
    {
7012
      if ((error=file->rnd_next(record)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7013 7014 7015 7016 7017 7018 7019 7020 7021
      {
	if (error == HA_ERR_RECORD_DELETED)
	  continue;
	if (error == HA_ERR_END_OF_FILE)
	  break;
	goto err;
      }
      if (compare_record(table, first_field) == 0)
      {
7022
	if ((error=file->delete_row(record)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7023 7024 7025 7026 7027
	  goto err;
      }
      else if (!found)
      {
	found=1;
7028
	file->position(record);	// Remember position
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7029 7030 7031 7032 7033
      }
    }
    if (!found)
      break;					// End of file
    /* Restart search on next row */
7034
    error=file->restart_rnd_next(record,file->ref);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7035 7036 7037 7038 7039 7040 7041 7042 7043 7044 7045 7046 7047 7048 7049 7050 7051 7052 7053 7054
  }

  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,
7055 7056
				      ulong key_length,
				      Item *having)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7057 7058 7059 7060 7061 7062 7063 7064 7065 7066 7067 7068 7069 7070 7071 7072 7073
{
  byte *key_buffer, *key_pos, *record=table->record[0];
  int error;
  handler *file=table->file;
  ulong extra_length=ALIGN_SIZE(key_length)-key_length;
  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);
7074

bar@bar.mysql.r18.ru's avatar
bar@bar.mysql.r18.ru committed
7075
  if (hash_init(&hash, &my_charset_bin, (uint) file->records, 0, 
7076
		key_length,(hash_get_key) 0, 0, 0))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7077 7078 7079 7080 7081 7082 7083 7084 7085 7086 7087 7088 7089 7090 7091 7092 7093 7094 7095 7096 7097 7098 7099 7100 7101 7102 7103 7104
  {
    my_free((char*) key_buffer,MYF(0));
    DBUG_RETURN(1);
  }
  {
    Field **ptr;
    for (ptr= first_field, field_length=field_lengths ; *ptr ; ptr++)
      (*field_length++)= (*ptr)->pack_length();
  }

  file->rnd_init();
  key_pos=key_buffer;
  for (;;)
  {
    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;
    }
7105 7106 7107 7108 7109
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
      continue;
7110
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7111 7112 7113 7114 7115 7116 7117 7118 7119 7120 7121 7122 7123 7124 7125

    /* copy fields to key buffer */
    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 */
    if (hash_search(&hash,key_pos-key_length,key_length))
    {
      /* Duplicated found ; Remove the row */
      if ((error=file->delete_row(record)))
	goto err;
    }
7126 7127
    else
      (void) hash_insert(&hash, key_pos-key_length);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7128 7129 7130 7131 7132 7133 7134 7135 7136 7137 7138 7139 7140 7141 7142 7143 7144 7145 7146
    key_pos+=extra_length;
  }
  my_free((char*) key_buffer,MYF(0));
  hash_free(&hash);
  file->extra(HA_EXTRA_NO_CACHE);
  (void) file->rnd_end();
  DBUG_RETURN(0);

err:
  my_free((char*) key_buffer,MYF(0));
  hash_free(&hash);
  file->extra(HA_EXTRA_NO_CACHE);
  (void) file->rnd_end();
  if (error)
    file->print_error(error,MYF(0));
  DBUG_RETURN(1);
}


7147
SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7148 7149 7150 7151 7152 7153 7154 7155 7156 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
{
  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())
      pos->field= ((Item_sum*) order->item[0])->tmp_table_field();
    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);
}


/*****************************************************************************
7182 7183 7184 7185
  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
7186 7187 7188 7189 7190 7191 7192 7193 7194
******************************************************************************/

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;
7195
  JOIN_TAB *join_tab;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7196 7197 7198 7199 7200
  DBUG_ENTER("join_init_cache");

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

7201 7202
  join_tab=tables;
  for (i=0 ; i < table_count ; i++,join_tab++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7203
  {
7204 7205 7206 7207
    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
7208 7209 7210 7211 7212 7213 7214 7215 7216 7217 7218 7219 7220 7221 7222 7223 7224 7225 7226 7227 7228 7229 7230 7231 7232 7233 7234 7235 7236 7237 7238 7239 7240 7241 7242 7243 7244 7245 7246
  }
  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;
7247
      copy->length=tables[i].table->null_bytes;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7248 7249 7250 7251 7252 7253 7254 7255 7256 7257 7258 7259 7260 7261 7262 7263 7264 7265 7266 7267 7268 7269 7270
      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->records=0; cache->ptr_record= (uint) ~0;
  cache->length=length+blobs*sizeof(char*);
  cache->blobs=blobs;
  *blob_ptr=0;					/* End sequentel */
7271
  size=max(thd->variables.join_buff_size, cache->length);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7272 7273 7274 7275 7276 7277 7278 7279 7280 7281 7282 7283 7284 7285 7286 7287 7288 7289 7290 7291 7292 7293 7294 7295 7296 7297 7298 7299 7300 7301 7302 7303 7304 7305 7306 7307 7308 7309 7310 7311
  if (!(cache->buff=(uchar*) my_malloc(size,MYF(0))))
    DBUG_RETURN(1);				/* Don't use cache */ /* purecov: inspected */
  cache->end=cache->buff+size;
  reset_cache(cache);
  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)
{
  ulong length;
  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;

  /*
7312
    There is room in cache. Put record there
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7313 7314 7315 7316 7317 7318 7319 7320
  */
  cache->records++;
  for (copy=cache->field ; copy < end_field; copy++)
  {
    if (copy->blob_field)
    {
      if (last_record)
      {
7321 7322
	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
7323 7324 7325 7326
	pos+=copy->length+sizeof(char*);
      }
      else
      {
7327 7328
	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
7329 7330 7331 7332 7333 7334 7335 7336 7337 7338 7339 7340 7341 7342 7343 7344 7345 7346 7347 7348 7349 7350 7351 7352 7353 7354 7355 7356 7357 7358 7359 7360 7361 7362 7363 7364 7365 7366 7367 7368 7369 7370 7371 7372 7373 7374 7375 7376 7377 7378 7379 7380 7381 7382 7383 7384
	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);
	memcpy(pos+1,str,length);
	*pos=(uchar) length;
	pos+=length+1;
      }
      else
      {
	memcpy(pos,copy->str,copy->length);
	pos+=copy->length;
      }
    }
  }
  cache->pos=pos;
  return last_record || (uint) (cache->end -pos) < cache->length;
}


static void
reset_cache(JOIN_CACHE *cache)
{
  cache->record_nr=0;
  cache->pos=cache->buff;
}


static void
read_cached_record(JOIN_TAB *tab)
{
  uchar *pos;
  uint length;
  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)
      {
7385 7386
	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
7387 7388 7389 7390 7391 7392 7393 7394 7395 7396 7397 7398 7399 7400 7401 7402 7403 7404 7405 7406 7407 7408 7409 7410 7411 7412 7413 7414 7415 7416 7417 7418 7419 7420 7421 7422 7423 7424 7425 7426 7427 7428 7429 7430 7431 7432 7433 7434 7435 7436 7437 7438 7439 7440
	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)
      {
	memcpy(copy->str,pos+1,length=(uint) *pos);
	memset(copy->str+length,' ',copy->length-length);
	pos+=1+length;
      }
      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);
  }
  if ((tab->ref.key_err=cp_buffer_from_ref(&tab->ref)) || diff)
    return 1;
  return memcmp(tab->ref.key_buff2, tab->ref.key_buff, tab->ref.key_length)
    != 0;
}


bool
cp_buffer_from_ref(TABLE_REF *ref)
{
  for (store_key **copy=ref->key_copy ; *copy ; copy++)
    if ((*copy)->copy())
      return 1;					// Something went wrong
  return 0;
}


/*****************************************************************************
7441
  Group and order functions
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7442 7443 7444
*****************************************************************************/

/*
7445 7446 7447
  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
7448 7449 7450
*/

static int
7451 7452
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
7453 7454
		   List<Item> &all_fields)
{
7455 7456
  Item *itemptr=*order->item;
  if (itemptr->type() == Item::INT_ITEM)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7457 7458 7459
  {						/* Order by position */
    Item *item=0;

7460
    uint count= (uint) ((Item_int*)itemptr)->value;
7461
    if (!count || count > fields.elements)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7462 7463
    {
      my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),
7464
		      MYF(0),itemptr->full_name(),
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7465 7466 7467
	       thd->where);
      return 1;
    }
7468 7469
    order->item= ref_pointer_array + count-1;
    order->in_field_list= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7470 7471
    return 0;
  }
7472
  uint counter;
7473
  Item **item= find_item_in_list(itemptr, fields, &counter, IGNORE_ERRORS);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7474 7475
  if (item)
  {
7476
    order->item= ref_pointer_array + counter;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7477 7478 7479 7480
    order->in_field_list=1;
    return 0;
  }
  order->in_field_list=0;
7481
  Item *it= *order->item;
7482 7483
  if (it->fix_fields(thd, tables, order->item) ||
      //'it' ressigned because fix_field can change it
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
7484
      (it= *order->item)->check_cols(1) ||
7485
      thd->is_fatal_error)
7486
    return 1;					// Wrong field 
7487 7488 7489 7490
  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
7491 7492 7493 7494
  return 0;
}

/*
7495 7496
  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
7497 7498
*/

7499 7500
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
7501 7502 7503 7504
{
  thd->where="order clause";
  for (; order; order=order->next)
  {
7505 7506
    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
7507 7508 7509 7510 7511 7512
      return 1;
  }
  return 0;
}


7513
int
7514 7515 7516
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
7517 7518 7519 7520 7521
{
  *hidden_group_fields=0;
  if (!order)
    return 0;				/* Everything is ok */

7522
  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7523 7524 7525 7526 7527 7528 7529 7530 7531
  {
    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";
7532
  for (; order; order=order->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7533
  {
7534 7535
    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
7536 7537 7538 7539 7540 7541 7542 7543 7544
      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;
    }
  }
7545
  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7546 7547 7548 7549 7550 7551 7552
  {
    /* Don't allow one to use fields that is not used in GROUP BY */
    Item *item;
    List_iterator<Item> li(fields);

    while ((item=li++))
    {
7553 7554
      if (item->type() != Item::SUM_FUNC_ITEM && !item->marker &&
	  !item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7555 7556 7557 7558 7559 7560 7561 7562 7563 7564 7565 7566 7567 7568
      {
	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;
}

/*
7569
  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
7570 7571 7572 7573 7574 7575 7576 7577 7578 7579
*/

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...
7580
  uint counter;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
7581
  for (; new_field ; new_field= new_field->next)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7582
  {
7583 7584
    if ((item= find_item_in_list(*new_field->item, fields, &counter,
				 IGNORE_ERRORS)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7585 7586 7587 7588
      new_field->item=item;			/* Change to shared Item */
    else
    {
      thd->where="procedure list";
7589
      if ((*new_field->item)->fix_fields(thd, tables, new_field->item))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7590 7591 7592 7593 7594 7595 7596 7597 7598
	DBUG_RETURN(1); /* purecov: inspected */
      all_fields.push_front(*new_field->item);
      new_field->item=all_fields.head_ref();
    }
  }
  DBUG_RETURN(0);
}

/*
7599 7600 7601
  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
7602 7603 7604
*/

static ORDER *
7605 7606
create_distinct_group(THD *thd, ORDER *order_list, List<Item> &fields, 
		      bool *all_order_by_fields_used)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7607 7608 7609 7610 7611
{
  List_iterator<Item> li(fields);
  Item *item;
  ORDER *order,*group,**prev;

7612
  *all_order_by_fields_used= 1;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7613 7614 7615 7616 7617 7618 7619 7620
  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)
    {
7621
      ORDER *ord=(ORDER*) thd->memdup((char*) order,sizeof(ORDER));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7622 7623 7624 7625 7626 7627
      if (!ord)
	return 0;
      *prev=ord;
      prev= &ord->next;
      (*ord->item)->marker=1;
    }
7628 7629
    else
      *all_order_by_fields_used= 0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7630 7631 7632 7633 7634 7635 7636 7637 7638
  }

  li.rewind();
  while ((item=li++))
  {
    if (item->const_item() || item->with_sum_func)
      continue;
    if (!item->marker)
    {
7639
      ORDER *ord=(ORDER*) thd->calloc(sizeof(ORDER));
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7640 7641 7642 7643 7644 7645 7646 7647 7648 7649 7650 7651 7652 7653
      if (!ord)
	return 0;
      ord->item=li.ref();
      ord->asc=1;
      *prev=ord;
      prev= &ord->next;
    }
  }
  *prev=0;
  return group;
}


/*****************************************************************************
7654
  Update join with count of the different type of fields
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7655 7656 7657
*****************************************************************************/

void
7658 7659
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
7660 7661 7662 7663
{
  List_iterator<Item> li(fields);
  Item *field;

7664
  param->field_count=param->sum_func_count=param->func_count=
7665
    param->hidden_field_count=0;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
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
  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
7691
    {
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7692
      param->func_count++;
7693 7694 7695
      if (reset_with_sum_func)
	field->with_sum_func=0;
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7696 7697 7698 7699 7700 7701 7702 7703 7704 7705 7706 7707 7708 7709 7710
  }
}


/*
  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)
  {
7711
    if ((*a->item)->eq(*b->item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7712 7713 7714 7715 7716 7717 7718 7719 7720 7721 7722 7723 7724 7725 7726 7727 7728 7729 7730 7731 7732 7733 7734 7735 7736 7737
      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)
  {
7738
    if (!(*a->item)->eq(*b->item,1))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7739 7740 7741
      DBUG_RETURN(0);
    map|=a->item[0]->used_tables();
  }
7742
  if (!map || (map & (RAND_TABLE_BIT | OUTER_REF_TABLE_BIT)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7743 7744
    DBUG_RETURN(0);

7745
  for (; !(map & tables->table->map) ; tables=tables->next) ;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7746 7747 7748 7749 7750 7751 7752 7753 7754 7755 7756 7757
  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)
{
7758 7759
  uint key_length=0, parts=0, null_parts=0;

bk@work.mysql.com's avatar
bk@work.mysql.com committed
7760 7761 7762 7763 7764 7765 7766 7767 7768 7769 7770 7771 7772 7773 7774 7775 7776 7777 7778 7779
  if (group)
    join->group= 1;
  for (; group ; group=group->next)
  {
    Field *field=(*group->item)->tmp_table_field();
    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)
7780
      null_parts++;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7781
  }
7782
  join->tmp_table_param.group_length=key_length+null_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7783
  join->tmp_table_param.group_parts=parts;
7784
  join->tmp_table_param.group_null_parts=null_parts;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7785 7786
}

7787 7788 7789 7790 7791 7792 7793 7794 7795 7796 7797 7798 7799 7800 7801 7802 7803 7804 7805 7806 7807 7808 7809 7810 7811 7812 7813 7814 7815 7816 7817
/*
  alloc group fields or take prepared (chached)

  SYNOPSYS
    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)
{
    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);
}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7818 7819

/*
7820 7821
  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
7822 7823 7824 7825 7826 7827 7828 7829 7830 7831 7832 7833 7834 7835 7836 7837 7838 7839 7840 7841 7842 7843
*/

static bool
alloc_group_fields(JOIN *join,ORDER *group)
{
  if (group)
  {
    for (; group ; group=group->next)
    {
      Item_buff *tmp=new_Item_buff(*group->item);
      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)
{
7844
  DBUG_ENTER("test_if_group_changed");
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7845 7846 7847 7848 7849 7850 7851 7852 7853
  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;
  }
7854 7855
  DBUG_PRINT("info", ("idx: %d", idx));
  DBUG_RETURN(idx);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7856 7857 7858 7859 7860
}



/*
7861
  Setup copy_fields to save fields at start of new group
7862 7863 7864 7865 7866 7867 7868 7869 7870 7871 7872 7873 7874 7875 7876 7877 7878 7879 7880

  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
7881 7882 7883
*/

bool
7884 7885
setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
		  Item **ref_pointer_array,
7886 7887
		  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
7888 7889
{
  Item *pos;
7890
  List_iterator_fast<Item> li(all_fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7891 7892
  Copy_field *copy;
  DBUG_ENTER("setup_copy_fields");
7893 7894 7895
  res_selected_fields.empty();
  res_all_fields.empty();
  List_iterator_fast<Item> itr(res_all_fields);
7896

7897
  uint i, border= all_fields.elements - elements;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7898 7899

  if (!(copy=param->copy_field= new Copy_field[param->field_count]))
7900
    goto err2;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7901 7902

  param->copy_funcs.empty();
7903
  for (i= 0; (pos= li++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7904 7905 7906
  {
    if (pos->type() == Item::FIELD_ITEM)
    {
7907
      Item_field *item;
7908
      if (!(item= new Item_field(thd, *((Item_field*) pos))))
7909 7910
	goto err;
      pos= item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7911 7912
      if (item->field->flags & BLOB_FLAG)
      {
7913
	if (!(pos= new Item_copy_string(pos)))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7914 7915 7916 7917
	  goto err;
	if (param->copy_funcs.push_back(pos))
	  goto err;
      }
7918 7919 7920 7921 7922 7923 7924 7925 7926 7927 7928 7929 7930 7931 7932
      else
      {
	/* 
	   set up save buffer and change result_field to point at 
	   saved value
	*/
	Field *field= item->field;
	item->result_field=field->new_field(&thd->mem_root,field->table);
	char *tmp=(char*) sql_alloc(field->pack_length()+1);
	if (!tmp)
	  goto err;
	copy->set(tmp, item->result_field);
	item->result_field->move_field(copy->to_ptr,copy->to_null_ptr,1);
	copy++;
      }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7933 7934 7935 7936 7937 7938 7939 7940 7941 7942 7943 7944 7945 7946 7947 7948
    }
    else if ((pos->type() == Item::FUNC_ITEM ||
	      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;
      if (param->copy_funcs.push_back(pos))
	goto err;
    }
7949 7950
    res_all_fields.push_back(pos);
    ref_pointer_array[((i < border)? all_fields.elements-i-1 : i-border)]=
7951
      pos;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7952
  }
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
7953
  param->copy_field_end= copy;
7954 7955 7956

  for (i= 0; i < border; i++)
    itr++;
7957
  itr.sublist(res_selected_fields, elements);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7958 7959 7960
  DBUG_RETURN(0);

 err:
7961
  delete [] param->copy_field;			// This is never 0
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7962
  param->copy_field=0;
7963
err2:
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7964 7965 7966 7967 7968
  DBUG_RETURN(TRUE);
}


/*
7969 7970 7971 7972
  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
7973 7974 7975 7976 7977 7978
*/

void
copy_fields(TMP_TABLE_PARAM *param)
{
  Copy_field *ptr=param->copy_field;
monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
7979
  Copy_field *end=param->copy_field_end;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7980

7981
  for (; ptr != end; ptr++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7982 7983
    (*ptr->do_copy)(ptr);

monty@tik.mysql.fi's avatar
monty@tik.mysql.fi committed
7984 7985
  List_iterator_fast<Item> &it=param->copy_funcs_it;
  it.rewind();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
7986 7987 7988 7989 7990 7991
  Item_copy_string *item;
  while ((item = (Item_copy_string*) it++))
    item->copy();
}


7992 7993
/*
  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
7994

7995 7996 7997 7998 7999 8000 8001 8002 8003
  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
8004
{
8005 8006 8007 8008 8009 8010 8011 8012 8013 8014 8015 8016 8017 8018 8019 8020 8021 8022 8023 8024 8025 8026 8027 8028 8029 8030 8031 8032 8033
  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);
}


bool JOIN::make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
			      bool before_group_by)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8034
{
8035 8036 8037
  List_iterator_fast<Item> it(all_fields);
  Item_sum **func;
  Item *item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8038 8039
  DBUG_ENTER("make_sum_func_list");

8040 8041
  func= sum_funcs;
  while ((item=it++))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8042
  {
8043
    if (item->type() == Item::SUM_FUNC_ITEM && !item->const_item())
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8044
    {
8045
      *func++= (Item_sum*) item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8046
      /* let COUNT(DISTINCT) create the temporary table */
8047
      if (((Item_sum*) item)->setup(thd))
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8048 8049 8050
	DBUG_RETURN(TRUE);
    }
  }
8051 8052 8053 8054 8055 8056 8057 8058 8059 8060 8061
  if (before_group_by && rollup.state == ROLLUP::STATE_INITED)
  {
    rollup.state= ROLLUP::STATE_READY;
    if (rollup_make_fields(all_fields, send_fields, &func))
      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;
  }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8062 8063 8064 8065 8066 8067
  *func=0;					// End marker
  DBUG_RETURN(FALSE);
}


/*
8068
  Change all funcs and sum_funcs to fields in tmp table,  and create
8069 8070 8071 8072 8073 8074 8075 8076 8077 8078 8079 8080 8081
  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
8082 8083 8084
*/

static bool
8085
change_to_use_tmp_fields(THD *thd, Item **ref_pointer_array,
8086 8087 8088
			 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
8089
{
8090
  List_iterator_fast<Item> it(all_fields);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8091
  Item *item_field,*item;
8092 8093
  res_selected_fields.empty();
  res_all_fields.empty();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8094

8095
  uint i, border= all_fields.elements - elements;
8096
  for (i= 0; (item= it++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8097 8098
  {
    Field *field;
8099
    
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8100
    if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM)
8101 8102
      item_field= item;
    else
8103
    {
8104
      if (item->type() == Item::FIELD_ITEM)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8105
      {
8106
	item_field= item->get_tmp_table_item(thd);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8107
      }
8108 8109 8110 8111 8112 8113 8114 8115 8116 8117 8118 8119 8120
      else if ((field= item->tmp_table_field()))
      {
	if (item->type() == Item::SUM_FUNC_ITEM && field->table->group)
	  item_field= ((Item_sum*) item)->result_item(field);
	else
	  item_field= (Item*) new Item_field(field);
	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];
8121
	  String str(buff,sizeof(buff),&my_charset_bin);
8122 8123 8124 8125
	  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
8126
#endif
8127 8128 8129
      }
      else
	item_field= item;
8130 8131 8132
    }
    res_all_fields.push_back(item_field);
    ref_pointer_array[((i < border)? all_fields.elements-i-1 : i-border)]=
8133
      item_field;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8134
  }
8135

8136
  List_iterator_fast<Item> itr(res_all_fields);
8137 8138
  for (i= 0; i < border; i++)
    itr++;
8139
  itr.sublist(res_selected_fields, elements);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8140 8141 8142 8143 8144
  return FALSE;
}


/*
8145 8146
  Change all sum_func refs to fields to point at fields in tmp table
  Change all funcs to be fields in tmp table
8147 8148 8149 8150 8151 8152 8153 8154 8155 8156

  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
8157 8158
    0	ok
    1	error
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8159 8160 8161
*/

static bool
8162
change_refs_to_tmp_fields(THD *thd, Item **ref_pointer_array,
8163 8164 8165
			  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
8166
{
8167
  List_iterator_fast<Item> it(all_fields);
8168
  Item *item, *new_item;
8169 8170
  res_selected_fields.empty();
  res_all_fields.empty();
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8171

8172
  uint i, border= all_fields.elements - elements;
8173
  for (i= 0; (item= it++); i++)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8174
  {
8175 8176
    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)]=
8177
      new_item;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8178
  }
8179

8180
  List_iterator_fast<Item> itr(res_all_fields);
8181 8182
  for (i= 0; i < border; i++)
    itr++;
8183
  itr.sublist(res_selected_fields, elements);
8184

8185
  return thd->is_fatal_error;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8186 8187 8188 8189 8190
}



/******************************************************************************
8191
  Code for calculating functions
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8192 8193 8194 8195 8196 8197 8198 8199 8200 8201 8202 8203 8204 8205 8206 8207 8208 8209 8210 8211 8212 8213 8214 8215 8216 8217 8218 8219 8220 8221
******************************************************************************/

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++)))
    func->update_field(0);
}


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

static void
copy_sum_funcs(Item_sum **func_ptr)
{
  Item_sum *func;
  for (; (func = *func_ptr) ; func_ptr++)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8222
    (void) func->save_in_result_field(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8223 8224 8225 8226
  return;
}


8227 8228
static bool
init_sum_functions(Item_sum **func_ptr, Item_sum **end_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8229
{
8230 8231 8232 8233 8234 8235 8236 8237 8238 8239 8240 8241
  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
8242 8243 8244 8245 8246 8247 8248 8249 8250 8251 8252 8253 8254 8255 8256 8257
}


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
8258
copy_funcs(Item **func_ptr)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8259
{
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8260
  Item *func;
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8261
  for (; (func = *func_ptr) ; func_ptr++)
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8262
    func->save_in_result_field(1);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8263 8264 8265
}


8266
/*
8267 8268
  Create a condition for a const reference and add this to the
  currenct select for the table
8269
*/
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8270 8271 8272 8273 8274 8275 8276 8277 8278 8279 8280 8281 8282 8283 8284

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++)
  {
8285 8286
    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
8287 8288 8289
    Item *value=join_tab->ref.items[i];
    cond->add(new Item_func_equal(new Item_field(field),value));
  }
8290
  if (thd->is_fatal_error)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8291
    DBUG_RETURN(TRUE);
8292 8293 8294 8295 8296

  /*
    Here we pass 0 as the first argument to fix_fields that don't need
    to do any stack checking (This is already done in the initial fix_fields).
  */
8297
  cond->fix_fields((THD *) 0,(TABLE_LIST *) 0, (Item**)&cond);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8298 8299 8300 8301 8302 8303 8304 8305 8306 8307 8308
  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);
}

8309 8310 8311 8312 8313 8314 8315 8316 8317 8318 8319 8320 8321 8322 8323 8324 8325

/*
  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
8326
/****************************************************************************
8327 8328 8329 8330 8331 8332 8333 8334 8335 8336 8337 8338 8339 8340 8341 8342 8343 8344 8345 8346 8347 8348 8349 8350 8351 8352 8353 8354 8355 8356 8357 8358 8359 8360 8361 8362 8363 8364 8365 8366 8367 8368 8369 8370 8371 8372 8373 8374 8375 8376 8377 8378 8379 8380 8381 8382 8383 8384 8385 8386 8387 8388 8389 8390 8391 8392 8393 8394 8395 8396 8397 8398 8399 8400 8401 8402 8403 8404 8405 8406 8407 8408 8409 8410 8411 8412 8413 8414 8415 8416 8417
  ROLLUP handling
****************************************************************************/

/* 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;

  if (!(rollup.fields= (List<Item>*) thd->alloc((sizeof(Item*) +
						 sizeof(List<Item>) +
						 ref_pointer_array_size)
						* send_group_parts)))
    return 1;
  rollup.ref_pointer_arrays= (Item***) (rollup.fields + send_group_parts);
  ref_array= (Item**) (rollup.ref_pointer_arrays+send_group_parts);
  rollup.item_null= new (&thd->mem_root) Item_null();

  /*
    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++)
  {
    List<Item> *fields= &rollup.fields[i];
    fields->empty();
    rollup.ref_pointer_arrays[i]= ref_array;
    ref_array+= all_fields.elements;
    for (j=0 ; j < fields_list.elements ; j++)
      fields->push_back(rollup.item_null);
  }
  return 0;
}
  

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

  SYNOPSIS
    rollup_make_fields()
    all_fields			List of all fields (hidden and real ones)
    fields			Pointer to selected fields
    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
*/

bool JOIN::rollup_make_fields(List<Item> &all_fields, List<Item> &fields,
			      Item_sum ***func)
{
  List_iterator_fast<Item> it(all_fields);
  Item *first_field= fields.head();
  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
    ...
  */

8418
  for (level=0 ; level < send_group_parts ; level++)
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 8449 8450 8451 8452 8453 8454 8455 8456 8457 8458 8459 8460 8461 8462 8463 8464 8465 8466 8467 8468 8469 8470 8471 8472 8473 8474 8475 8476 8477 8478 8479 8480 8481 8482 8483 8484 8485 8486 8487 8488 8489 8490 8491 8492 8493 8494 8495 8496 8497 8498 8499 8500 8501 8502 8503 8504 8505 8506 8507 8508 8509 8510 8511 8512 8513 8514 8515 8516 8517 8518 8519 8520 8521 8522 8523 8524 8525 8526 8527 8528 8529 8530 8531 8532 8533 8534 8535 8536 8537 8538 8539
  {
    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 */
    Item **ref_array= ref_array_start + all_fields.elements-1;

    /* 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)++;
      }
      else if (real_fields)
      {
	/* Check if this is something that is part of this group by */
	ORDER *group;
	for (group= start_group ; group ; group= group->next)
	{
	  if (*group->item == item)
	  {
	    /*
	      This is an element that is used by the GROUP BY and should be
	      set to NULL in this level
	    */
	    item->maybe_null= 1;		// Value will be null sometimes
	    item= rollup.item_null;
	    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()))
    {
      if (send_records < unit->select_limit_cnt &&
	  result->send_data(rollup.fields[i]))
	return 1;
      send_records++;
    }
  }
  /* Restore ref_pointer_array */
  set_items_ref_array(current_ref_pointer_array);
  return 0;
}


bk@work.mysql.com's avatar
bk@work.mysql.com committed
8540
/****************************************************************************
8541 8542
  EXPLAIN handling

8543
  Send a description about what how the select will be done to stdout
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8544 8545
****************************************************************************/

monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
8546
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
8547
			    bool distinct,const char *message)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8548 8549
{
  List<Item> field_list;
8550
  List<Item> item_list;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
8551
  THD *thd=join->thd;
8552
  SELECT_LEX *select_lex = &(join->thd->lex.select_lex);
8553
  select_result *result=join->result;
8554
  Item *item_null= new Item_null();
8555
  CHARSET_INFO *cs= &my_charset_latin1;
monty@tramp.mysql.fi's avatar
monty@tramp.mysql.fi committed
8556
  DBUG_ENTER("select_describe");
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8557 8558 8559
  DBUG_PRINT("info", ("Select 0x%lx, type %s, message %s", 
		      (ulong)join->select_lex, join->select_lex->type,
		      message));
8560
  /* Don't log this into the slow query log */
8561
  select_lex->options&= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8562
  join->unit->offset_limit_cnt= 0;
8563

8564
  if (message)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8565
  {
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8566 8567
    item_list.push_back(new Item_int((int32) join->select_lex->select_number));
    item_list.push_back(new Item_string(join->select_lex->type,
8568
					strlen(join->select_lex->type), cs));
8569
    for (uint i=0 ; i < 7; i++)
8570
      item_list.push_back(item_null);
8571
    item_list.push_back(new Item_string(message,strlen(message),cs));
8572
    if (result->send_data(item_list))
8573
      join->error= 1;
8574 8575 8576 8577 8578
  }
  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
8579
    {
8580 8581
      JOIN_TAB *tab=join->join_tab+i;
      TABLE *table=tab->table;
8582
      char buff[512],*buff_ptr=buff;
8583
      char buff1[512], buff2[512];
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8584
      char derived_name[64];
8585 8586
      String tmp1(buff1,sizeof(buff1),cs);
      String tmp2(buff2,sizeof(buff2),cs);
8587 8588 8589
      tmp1.length(0);
      tmp2.length(0);

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8590
      item_list.empty();
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8591 8592 8593 8594
      item_list.push_back(new Item_int((int32) 
				       join->select_lex->select_number));
      item_list.push_back(new Item_string(join->select_lex->type,
					  strlen(join->select_lex->type),
8595
					  cs));
8596 8597
      if (tab->type == JT_ALL && tab->select && tab->select->quick)
	tab->type= JT_RANGE;
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8598
      if (table->derived_select_number)
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8599
      {
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8600 8601 8602
	/* Derived table name generation */
	int len= my_snprintf(derived_name, sizeof(derived_name)-1,
			     "<derived%u>",
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8603
			     table->derived_select_number);
monty@mashka.mysql.fi's avatar
monty@mashka.mysql.fi committed
8604
	item_list.push_back(new Item_string(derived_name, len, cs));
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8605 8606 8607 8608
      }
      else
	item_list.push_back(new Item_string(table->table_name,
					    strlen(table->table_name),
8609
					    cs));
8610 8611
      item_list.push_back(new Item_string(join_type_str[tab->type],
					  strlen(join_type_str[tab->type]),
8612
					  cs));
8613 8614 8615
      key_map bits;
      uint j;
      for (j=0,bits=tab->keys ; bits ; j++,bits>>=1)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8616
      {
8617 8618
	if (bits & 1)
	{
8619 8620 8621
	  if (tmp1.length())
	    tmp1.append(',');
	  tmp1.append(table->key_info[j].name);
8622
	}
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8623
      }
8624
      if (tmp1.length())
8625
	item_list.push_back(new Item_string(tmp1.ptr(),tmp1.length(),cs));
8626
      else
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
8627
 	item_list.push_back(item_null);
8628
      if (tab->ref.key_parts)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8629
      {
8630 8631
	KEY *key_info=table->key_info+ tab->ref.key;
	item_list.push_back(new Item_string(key_info->name,
8632 8633
					    strlen(key_info->name),
					    system_charset_info));
8634
	item_list.push_back(new Item_int((int32) tab->ref.key_length));
8635 8636
	for (store_key **ref=tab->ref.key_copy ; *ref ; ref++)
	{
8637 8638 8639
	  if (tmp2.length())
	    tmp2.append(',');
	  tmp2.append((*ref)->name());
8640
	}
8641
	item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length(),cs));
8642 8643 8644
      }
      else if (tab->type == JT_NEXT)
      {
8645 8646
	KEY *key_info=table->key_info+ tab->index;
	item_list.push_back(new Item_string(key_info->name,
8647
					    strlen(key_info->name),cs));
8648 8649
	item_list.push_back(new Item_int((int32) key_info->key_length));
	item_list.push_back(item_null);
8650 8651 8652
      }
      else if (tab->select && tab->select->quick)
      {
8653 8654
	KEY *key_info=table->key_info+ tab->select->quick->index;
	item_list.push_back(new Item_string(key_info->name,
8655
					    strlen(key_info->name),cs));
monty@narttu.mysql.fi's avatar
monty@narttu.mysql.fi committed
8656 8657
	item_list.push_back(new Item_int((int32) tab->select->quick->
					 max_used_key_length));
8658
	item_list.push_back(item_null);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8659 8660 8661
      }
      else
      {
8662 8663 8664
	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
8665
      }
8666 8667 8668
      item_list.push_back(new Item_int((longlong) (ulonglong)
				       join->best_positions[i]. records_read,
				       21));
8669 8670 8671 8672 8673 8674
      my_bool key_read=table->key_read;
      if (tab->type == JT_NEXT &&
	  ((table->used_keys & ((key_map) 1 << tab->index))))
	key_read=1;
      
      if (tab->info)
8675
	item_list.push_back(new Item_string(tab->info,strlen(tab->info),cs));
8676
      else
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8677
      {
8678
	if (tab->select)
8679
	{
8680 8681 8682 8683 8684 8685 8686 8687
	  if (tab->use_quick == 2)
	  {
	    sprintf(buff_ptr,"; Range checked for each record (index map: %u)",
		    tab->keys);
	    buff_ptr=strend(buff_ptr);
	  }
	  else
	    buff_ptr=strmov(buff_ptr,"; Using where");
8688
	}
8689 8690 8691 8692 8693 8694 8695 8696 8697 8698 8699 8700 8701 8702
	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");
	}
8703
	if (distinct & test_all_bits(used_tables,thd->used_tables))
8704 8705
	  buff_ptr= strmov(buff_ptr,"; Distinct");
	if (buff_ptr == buff)
8706 8707
	  buff_ptr+= 2;				// Skip inital "; "
	item_list.push_back(new Item_string(buff+2,(uint) (buff_ptr - buff)-2,
8708
					    cs));
8709 8710 8711
      }
      // For next iteration
      used_tables|=table->map;
8712
      if (result->send_data(item_list))
8713
	join->error= 1;
8714
    }
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8715
  }
8716 8717 8718 8719 8720 8721 8722
  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
8723 8724 8725
  DBUG_VOID_RETURN;
}

8726

8727 8728
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
8729
  DBUG_ENTER("mysql_explain_union");
8730 8731 8732 8733 8734 8735 8736 8737
  int res= 0;
  SELECT_LEX *first= unit->first_select();
  for (SELECT_LEX *sl= first;
       sl;
       sl= sl->next_select())
  {
    res= mysql_explain_select(thd, sl,
			      (((&thd->lex.select_lex)==sl)?
8738
			       ((thd->lex.all_selects_list != sl)?"PRIMARY":
8739 8740
				"SIMPLE"):
			       ((sl == first)?
8741 8742
				((sl->linkage == DERIVED_TABLE_TYPE) ?
				 "DERIVED":
8743 8744 8745
				((sl->dependent)?"DEPENDENT SUBQUERY":
				 (sl->uncacheable?"UNCACHEABLE SUBQUERY":
				   "SUBQUERY"))):
8746
				((sl->dependent)?"DEPENDENT UNION":
8747 8748
				 sl->uncacheable?"UNCACHEABLE UNION":
				  "UNION"))),
8749 8750 8751 8752 8753
			      result);
    if (res)
      break;

  }
8754 8755
  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
8756
  DBUG_RETURN(res);
8757 8758
}

8759

bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8760 8761
int mysql_explain_select(THD *thd, SELECT_LEX *select_lex, char const *type, 
			 select_result *result)
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8762
{
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8763 8764
  DBUG_ENTER("mysql_explain_select");
  DBUG_PRINT("info", ("Select 0x%lx, type %s", (ulong)select_lex, type))
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8765
  select_lex->type= type;
8766
  thd->lex.current_select= select_lex;
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8767
  SELECT_LEX_UNIT *unit=  select_lex->master_unit();
8768 8769 8770
  int res= mysql_select(thd, &select_lex->ref_pointer_array,
			(TABLE_LIST*) select_lex->table_list.first,
			select_lex->with_wild, select_lex->item_list,
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8771
			select_lex->where,
8772 8773
			select_lex->order_list.elements +
			select_lex->group_list.elements,
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8774 8775 8776 8777 8778
			(ORDER*) select_lex->order_list.first,
			(ORDER*) select_lex->group_list.first,
			select_lex->having,
			(ORDER*) thd->lex.proc_list.first,
			select_lex->options | thd->options | SELECT_DESCRIBE,
8779
			result, unit, select_lex, 0);
bell@sanja.is.com.ua's avatar
bell@sanja.is.com.ua committed
8780
  DBUG_RETURN(res);
bk@work.mysql.com's avatar
bk@work.mysql.com committed
8781
}