sql_select.cc 200 KB
Newer Older
unknown's avatar
unknown committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB

   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"
unknown's avatar
unknown committed
26

27
#include "opt_ft.h"
unknown's avatar
unknown committed
28

unknown's avatar
unknown committed
29 30 31 32 33 34
#include <m_ctype.h>
#include <hash.h>
#include <ft_global.h>
#include <assert.h>

const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
35
			      "MAYBE_REF","ALL","range","index","fulltext" };
unknown's avatar
unknown committed
36 37

static bool make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
unknown's avatar
unknown committed
38
				 DYNAMIC_ARRAY *keyuse);
39 40
static bool update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,
				JOIN_TAB *join_tab,
41
                                uint tables,COND *conds,table_map table_map);
unknown's avatar
unknown committed
42 43
static int sort_keyuse(KEYUSE *a,KEYUSE *b);
static void set_position(JOIN *join,uint index,JOIN_TAB *table,KEYUSE *key);
44 45
static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, KEYUSE *org_keyuse,
			       table_map used_tables);
unknown's avatar
unknown committed
46 47 48 49 50 51
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);
unknown's avatar
unknown committed
52 53
static store_key *get_store_key(THD *thd,
				KEYUSE *keyuse, table_map used_tables,
unknown's avatar
unknown committed
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
				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);
static void join_free(JOIN *join);
static bool only_eq_ref_tables(JOIN *join,ORDER *order,table_map tables);
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);
static int return_zero_rows(select_result *res,TABLE_LIST *tables,
			    List<Item> &fields, bool send_row,
			    uint select_options, const char *info,
			    Item *having, Procedure *proc);
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,
74
				    ulong options);
unknown's avatar
unknown committed
75 76 77 78 79 80 81 82 83 84 85 86 87 88
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);
89
static int join_read_const_table(JOIN_TAB *tab, POSITION *pos);
unknown's avatar
unknown committed
90 91 92 93
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);
94
static int join_read_last_key(JOIN_TAB *tab);
unknown's avatar
unknown committed
95 96 97 98 99
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);
100 101 102 103 104 105
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);
unknown's avatar
unknown committed
106 107 108 109 110 111 112
static int join_ft_read_first(JOIN_TAB *tab);
static int join_ft_read_next(READ_RECORD *info);
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,
113
				    ha_rows select_limit, bool no_changes);
unknown's avatar
unknown committed
114
static int create_sort_index(JOIN_TAB *tab,ORDER *order,ha_rows select_limit);
115 116
static int remove_duplicates(JOIN *join,TABLE *entry,List<Item> &fields,
			     Item *having);
unknown's avatar
unknown committed
117
static int remove_dup_with_compare(THD *thd, TABLE *entry, Field **field,
118
				   ulong offset,Item *having);
unknown's avatar
unknown committed
119 120
static int remove_dup_with_hash_index(THD *thd, TABLE *table,
				      uint field_count, Field **first_field,
121
				      ulong key_length,Item *having);
unknown's avatar
unknown committed
122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137
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 int setup_group(THD *thd,TABLE_LIST *tables,List<Item> &fields,
		       List<Item> &all_fields, ORDER *order, bool *hidden);
static bool setup_new_fields(THD *thd,TABLE_LIST *tables,List<Item> &fields,
			     List<Item> &all_fields,ORDER *new_order);
static ORDER *create_distinct_group(ORDER *order, List<Item> &fields);
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);
static bool alloc_group_fields(JOIN *join,ORDER *group);
static bool make_sum_func_list(JOIN *join,List<Item> &fields);
138
static bool change_to_use_tmp_fields(List<Item> &func);
unknown's avatar
unknown committed
139 140 141 142 143 144 145
static bool change_refs_to_tmp_fields(THD *thd, List<Item> &func);
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);
static void init_sum_functions(Item_sum **func);
static bool update_sum_func(Item_sum **func);
unknown's avatar
unknown committed
146
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
unknown's avatar
unknown committed
147
			    bool distinct, const char *message=NullS);
148
static void describe_info(THD *thd, const char *info);
unknown's avatar
unknown committed
149

150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176
/*
  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;
  if (select_lex->next)
    res=mysql_union(thd,lex,result);
  else
    res=mysql_select(thd,(TABLE_LIST*) select_lex->table_list.first,
		     select_lex->item_list,
		     select_lex->where,
		     (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,
		     result);
  if (res && result)
    result->abort();
  delete result;
  return res;
}


unknown's avatar
unknown committed
177 178
/*****************************************************************************
** check fields, find best join, do the select and output fields.
unknown's avatar
unknown committed
179
** mysql_select assumes that all tables are already opened
unknown's avatar
unknown committed
180 181 182 183 184
*****************************************************************************/

int
mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds,
	     ORDER *order, ORDER *group,Item *having,ORDER *proc_param,
unknown's avatar
unknown committed
185
	     ulong select_options,select_result *result)
unknown's avatar
unknown committed
186 187
{
  TABLE		*tmp_table;
unknown's avatar
unknown committed
188
  int		error, tmp_error;
unknown's avatar
unknown committed
189
  bool		need_tmp,hidden_group_fields;
unknown's avatar
unknown committed
190
  bool		simple_order,simple_group,no_order, skip_sort_order, buffer_result;
unknown's avatar
unknown committed
191 192 193 194 195 196 197
  Item::cond_result cond_value;
  SQL_SELECT	*select;
  DYNAMIC_ARRAY keyuse;
  JOIN		join;
  Procedure	*procedure;
  List<Item>	all_fields(fields);
  bool		select_distinct;
unknown's avatar
unknown committed
198
  SELECT_LEX *select_lex = &(thd->lex.select_lex);
199
  SELECT_LEX *cur_sel = thd->lex.select;
unknown's avatar
unknown committed
200 201 202 203 204
  DBUG_ENTER("mysql_select");

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

  select_distinct=test(select_options & SELECT_DISTINCT);
unknown's avatar
unknown committed
205
  buffer_result=test(select_options & OPTION_BUFFER_RESULT) && !test(select_options & OPTION_FOUND_ROWS);
unknown's avatar
unknown committed
206 207
  tmp_table=0;
  select=0;
208
  no_order=skip_sort_order=0;
unknown's avatar
unknown committed
209 210
  bzero((char*) &keyuse,sizeof(keyuse));
  thd->proc_info="init";
unknown's avatar
unknown committed
211
  thd->used_tables=0;				// Updated by setup_fields
unknown's avatar
unknown committed
212

213
  if (setup_tables(tables) ||
unknown's avatar
unknown committed
214
      setup_fields(thd,tables,fields,1,&all_fields,1) ||
unknown's avatar
unknown committed
215 216
      setup_conds(thd,tables,&conds) ||
      setup_order(thd,tables,fields,all_fields,order) ||
unknown's avatar
unknown committed
217
      setup_group(thd,tables,fields,all_fields,group,&hidden_group_fields))
unknown's avatar
unknown committed
218 219 220 221 222 223 224 225 226 227 228
    DBUG_RETURN(-1);				/* purecov: inspected */

  if (having)
  {
    thd->where="having clause";
    thd->allow_sum_func=1;
    if (having->fix_fields(thd,tables) || thd->fatal_error)
      DBUG_RETURN(-1);				/* purecov: inspected */
    if (having->with_sum_func)
      having->split_sum_func(all_fields);
  }
229
  if (setup_ftfuncs(thd)) /* should be after having->fix_fields */
unknown's avatar
unknown committed
230
    DBUG_RETURN(-1);
unknown's avatar
unknown committed
231 232 233 234 235 236 237 238 239 240 241 242
  /*
    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;
    */
  join.table=0;
  join.tables=0;
  {
    if (!group)
    {
      uint flag=0;
unknown's avatar
unknown committed
243
      List_iterator_fast<Item> it(fields);
unknown's avatar
unknown committed
244 245 246 247 248
      Item *item;
      while ((item= it++))
      {
	if (item->with_sum_func)
	  flag|=1;
unknown's avatar
unknown committed
249
	else if (!(flag & 2) && !item->const_item())
unknown's avatar
unknown committed
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303
	  flag|=2;
      }
      if (flag == 3)
      {
	my_error(ER_MIX_OF_GROUP_FUNC_AND_FIELDS,MYF(0));
	DBUG_RETURN(-1);
      }
    }
    TABLE_LIST *table;
    for (table=tables ; table ; table=table->next)
      join.tables++;
  }
  procedure=setup_procedure(thd,proc_param,result,fields,&error);
  if (error)
    DBUG_RETURN(-1);				/* purecov: inspected */
  if (procedure)
  {
    if (setup_new_fields(thd,tables,fields,all_fields,procedure->param_fields))
    {						/* purecov: inspected */
      delete procedure;				/* purecov: inspected */
      DBUG_RETURN(-1);				/* purecov: inspected */
    }
    if (procedure->group)
    {
      if (!test_if_subpart(procedure->group,group))
      {						/* purecov: inspected */
	my_message(0,"Can't handle procedures with differents groups yet",
		   MYF(0));			/* purecov: inspected */
	delete procedure;			/* purecov: inspected */
	DBUG_RETURN(-1);			/* purecov: inspected */
      }
    }
#ifdef NOT_NEEDED
    else if (!group && procedure->flags & PROC_GROUP)
    {
      my_message(0,"Select must have a group with this procedure",MYF(0));
      delete procedure;
      DBUG_RETURN(-1);
    }
#endif
    if (order && (procedure->flags & PROC_NO_SORT))
    { /* purecov: inspected */
      my_message(0,"Can't use order with this procedure",MYF(0)); /* purecov: inspected */
      delete procedure; /* purecov: inspected */
      DBUG_RETURN(-1); /* purecov: inspected */
    }
  }

  /* Init join struct */
  join.thd=thd;
  join.lock=thd->lock;
  join.join_tab=0;
  join.tmp_table_param.copy_field=0;
  join.sum_funcs=0;
304
  join.send_records=join.found_records=join.examined_rows=0;
unknown's avatar
unknown committed
305 306 307 308
  join.tmp_table_param.end_write_records= HA_POS_ERROR;
  join.first_record=join.sort_and_group=0;
  join.select_options=select_options;
  join.result=result;
unknown's avatar
unknown committed
309
  count_field_types(&join.tmp_table_param,all_fields,0);
unknown's avatar
unknown committed
310 311
  join.const_tables=0;
  join.having=0;
312
  join.do_send_rows = 1;
unknown's avatar
unknown committed
313
  join.group= group != 0;
unknown's avatar
unknown committed
314 315
  join.row_limit= ((select_distinct || order || group) ? HA_POS_ERROR :
		   thd->select_limit);
unknown's avatar
unknown committed
316 317 318 319

#ifdef RESTRICTED_GROUP
  if (join.sum_func_count && !group && (join.func_count || join.field_count))
  {
unknown's avatar
unknown committed
320
    my_message(ER_WRONG_SUM_SELECT,ER(ER_WRONG_SUM_SELECT),MYF(0));
unknown's avatar
unknown committed
321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355
    delete procedure;
    DBUG_RETURN(-1);
  }
#endif
  if (!procedure && result->prepare(fields))
  {						/* purecov: inspected */
    DBUG_RETURN(-1);				/* purecov: inspected */
  }

#ifdef HAVE_REF_TO_FIELDS			// Not done yet
  /* Add HAVING to WHERE if possible */
  if (having && !group && ! join.sum_func_count)
  {
    if (!conds)
    {
      conds=having;
      having=0;
    }
    else if ((conds=new Item_cond_and(conds,having)))
    {
      conds->fix_fields(thd,tables);
      conds->change_ref_to_fields(thd,tables);
      having=0;
    }
  }
#endif

  conds=optimize_cond(conds,&cond_value);
  if (thd->fatal_error)				// Out of memory
  {
    delete procedure;
    DBUG_RETURN(0);
  }
  if (cond_value == Item::COND_FALSE || !thd->select_limit)
  {					/* Impossible cond */
unknown's avatar
unknown committed
356 357 358 359 360 361 362
    if (select_options & SELECT_DESCRIBE && select_lex->next)
      select_describe(&join,false,false,false,"Impossible WHERE");
    else 
      error=return_zero_rows(result, tables, fields,
			     join.tmp_table_param.sum_func_count != 0 && !group,
			     select_options,"Impossible WHERE",having,
			     procedure);
unknown's avatar
unknown committed
363 364 365 366 367 368 369 370 371 372 373 374
    delete procedure;
    DBUG_RETURN(error);
  }

  /* Optimize count(*), min() and max() */
  if (tables && join.tmp_table_param.sum_func_count && ! group)
  {
    int res;
    if ((res=opt_sum_query(tables, all_fields, conds)))
    {
      if (res < 0)
      {
unknown's avatar
unknown committed
375 376 377 378 379 380
	if (select_options & SELECT_DESCRIBE && select_lex->next)
	  select_describe(&join,false,false,false,"No matching min/max row");
	else 
	  error=return_zero_rows(result, tables, fields, !group,
				 select_options,"No matching min/max row",
				 having,procedure);
unknown's avatar
unknown committed
381 382 383 384 385
	delete procedure;
	DBUG_RETURN(error);
      }
      if (select_options & SELECT_DESCRIBE)
      {
unknown's avatar
unknown committed
386 387 388 389
	if (select_lex->next)
	  select_describe(&join,false,false,false,"Select tables optimized away");
	else
	  describe_info(thd,"Select tables optimized away");
unknown's avatar
unknown committed
390
	delete procedure;
unknown's avatar
unknown committed
391
	DBUG_RETURN(error);
unknown's avatar
unknown committed
392 393 394 395 396 397 398 399
      }
      tables=0;					// All tables resolved
    }
  }
  if (!tables)
  {						// Only test of functions
    error=0;
    if (select_options & SELECT_DESCRIBE)
unknown's avatar
unknown committed
400 401 402 403 404 405
    {
      if (select_lex->next)
	select_describe(&join,false,false,false,"No tables used");
      else
	describe_info(thd,"No tables used");
    }
unknown's avatar
unknown committed
406 407 408 409 410
    else
    {
      result->send_fields(fields,1);
      if (!having || having->val_int())
      {
411
	if (join.do_send_rows && result->send_data(fields))
unknown's avatar
unknown committed
412 413 414 415 416 417 418 419 420 421 422
	{
	  result->send_error(0,NullS);		/* purecov: inspected */
	  error=1;
	}
	else
	  error=(int) result->send_eof();
      }
      else
	error=(int) result->send_eof();
    }
    delete procedure;
unknown's avatar
unknown committed
423
    DBUG_RETURN(error);
unknown's avatar
unknown committed
424 425 426 427 428 429 430
  }

  error = -1;
  join.sort_by_table=get_sort_by_table(order,group,tables);

  /* Calculate how to do the join */
  thd->proc_info="statistics";
431
  if (make_join_statistics(&join,tables,conds,&keyuse) || thd->fatal_error)
unknown's avatar
unknown committed
432 433
    goto err;
  thd->proc_info="preparing";
unknown's avatar
unknown committed
434
  result->initialize_tables(&join);
435 436
  if (join.const_table_map != join.found_const_table_map &&
      !(select_options & SELECT_DESCRIBE))
unknown's avatar
unknown committed
437 438 439
  {
    error=return_zero_rows(result,tables,fields,
			   join.tmp_table_param.sum_func_count != 0 &&
440
			   !group,0,"",having,procedure);
unknown's avatar
unknown committed
441 442 443 444 445 446 447 448 449 450
    goto err;
  }
  if (!(thd->options & OPTION_BIG_SELECTS) &&
      join.best_read > (double) thd->max_join_size &&
      !(select_options & SELECT_DESCRIBE))
  {						/* purecov: inspected */
    result->send_error(ER_TOO_BIG_SELECT,ER(ER_TOO_BIG_SELECT)); /* purecov: inspected */
    error= 1;					/* purecov: inspected */
    goto err;					/* purecov: inspected */
  }
unknown's avatar
unknown committed
451 452
  if (join.const_tables && !thd->locked_tables &&
      !(select_options & SELECT_NO_UNLOCK))
453 454 455 456 457 458 459 460 461 462 463 464 465 466
  {
    TABLE **table, **end;
    for (table=join.table, end=table + join.const_tables ;
	 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();
    }
unknown's avatar
unknown committed
467
    mysql_unlock_some_tables(thd, join.table,join.const_tables);
468
  }
469 470 471 472 473
  if (!conds && join.outer_join)
  {
    /* Handle the case where we have an OUTER JOIN without a WHERE */
    conds=new Item_int((longlong) 1,1);	// Always true
  }
unknown's avatar
unknown committed
474 475 476 477 478 479 480 481 482
  select=make_select(*join.table, join.const_table_map,
		     join.const_table_map,conds,&error);
  if (error)
  { /* purecov: inspected */
    error= -1; /* purecov: inspected */
    goto err; /* purecov: inspected */
  }
  if (make_join_select(&join,select,conds))
  {
unknown's avatar
unknown committed
483 484 485 486 487 488 489 490
    if (select_options & SELECT_DESCRIBE && select_lex->next)
      select_describe(&join,false,false,false,"Impossible WHERE noticed after reading const tables");
    else 
      error=return_zero_rows(result,tables,fields,
			     join.tmp_table_param.sum_func_count != 0 && !group,
			     select_options,
			     "Impossible WHERE noticed after reading const tables",
			     having,procedure);
unknown's avatar
unknown committed
491 492 493 494 495 496 497 498 499 500 501 502 503
    goto err;
  }

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

  /* Optimize distinct away if possible */
  order=remove_const(&join,order,conds,&simple_order);
  if (group || join.tmp_table_param.sum_func_count)
  {
    if (! hidden_group_fields)
      select_distinct=0;
  }
  else if (select_distinct && join.tables - join.const_tables == 1 &&
504 505
	   (thd->select_limit == HA_POS_ERROR ||
	    (join.select_options & OPTION_FOUND_ROWS) ||
506
	    order &&
unknown's avatar
unknown committed
507 508 509
	    !(skip_sort_order=
	      test_if_skip_sort_order(&join.join_tab[join.const_tables],
				      order, thd->select_limit,1))))
unknown's avatar
unknown committed
510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
  {
    if ((group=create_distinct_group(order,fields)))
    {
      select_distinct=0;
      no_order= !order;
      join.group=1;				// For end_write_group
    }
    else if (thd->fatal_error)			// End of memory
      goto err;
  }
  group=remove_const(&join,group,conds,&simple_group);
  if (!group && join.group)
  {
    order=0;					// The output has only one row
    simple_order=1;
  }

  calc_group_buffer(&join,group);
  join.send_group_parts=join.tmp_table_param.group_parts; /* Save org parts */
  if (procedure && procedure->group)
  {
    group=procedure->group=remove_const(&join,procedure->group,conds,
					&simple_group);
    calc_group_buffer(&join,group);
  }

  if (test_if_subpart(group,order) ||
      (!group && join.tmp_table_param.sum_func_count))
    order=0;

unknown's avatar
unknown committed
540
  // Can't use sort on head table if using row cache
unknown's avatar
unknown committed
541 542 543 544 545 546 547 548 549 550
  if (join.full_join)
  {
    if (group)
      simple_group=0;
    if (order)
      simple_order=0;
  }

  need_tmp= (join.const_tables != join.tables &&
	     ((select_distinct || !simple_order || !simple_group) ||
unknown's avatar
unknown committed
551
	      (group && order) || buffer_result));
unknown's avatar
unknown committed
552

unknown's avatar
unknown committed
553 554 555
  // No cache for MATCH
  make_join_readinfo(&join,
		     (select_options & (SELECT_DESCRIBE |
556
					SELECT_NO_JOIN_CACHE)) |
557
     (cur_sel->ftfunc_list.elements ? SELECT_NO_JOIN_CACHE : 0));
unknown's avatar
unknown committed
558 559 560 561 562 563 564 565 566 567 568 569

  /* 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. */

#ifdef HAVE_INNOBASE_DB
  if (need_tmp || select_distinct || group || order)
  {
    for (uint i_h = join.const_tables; i_h < join.tables; i_h++)
    {
570
      TABLE*	  table_h = join.join_tab[i_h].table;
571
      if (table_h->db_type == DB_TYPE_INNODB)
572
	table_h->file->extra(HA_EXTRA_DONT_USE_CURSOR_TO_UPDATE);
unknown's avatar
unknown committed
573 574 575 576
    }
  }
#endif

unknown's avatar
unknown committed
577 578 579 580 581 582 583 584
  DBUG_EXECUTE("info",TEST_join(&join););
  /*
    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.
    */
  if ((order || group) && join.join_tab[join.const_tables].type != JT_ALL &&
585
      join.join_tab[join.const_tables].type != JT_FT &&
unknown's avatar
unknown committed
586 587 588 589 590 591 592 593
      (order && simple_order || group && simple_group))
  {
    if (add_ref_to_table_cond(thd,&join.join_tab[join.const_tables]))
      goto err;
  }

  if (!(select_options & SELECT_BIG_RESULT) &&
      ((group && join.const_tables != join.tables &&
594 595
	(!simple_group ||
	 !test_if_skip_sort_order(&join.join_tab[join.const_tables], group,
unknown's avatar
merge  
unknown committed
596
				  thd->select_limit,0))) ||
unknown's avatar
unknown committed
597 598 599 600 601 602 603 604 605 606 607 608
       select_distinct) &&
      join.tmp_table_param.quick_group && !procedure)
  {
    need_tmp=1; simple_order=simple_group=0;	// Force tmp table without sort
  }

  if (select_options & SELECT_DESCRIBE)
  {
    if (!order && !no_order)
      order=group;
    if (order &&
	(join.const_tables == join.tables ||
609 610
	 (simple_order &&
	  test_if_skip_sort_order(&join.join_tab[join.const_tables], order,
unknown's avatar
merge  
unknown committed
611 612 613
				  (join.const_tables != join.tables - 1 ||
				   (join.select_options & OPTION_FOUND_ROWS)) ?
				  HA_POS_ERROR : thd->select_limit,0))))
unknown's avatar
unknown committed
614 615
      order=0;
    select_describe(&join,need_tmp,
616
		    order != 0 && !skip_sort_order,
unknown's avatar
unknown committed
617
		    select_distinct);
unknown's avatar
unknown committed
618 619 620 621
    error=0;
    goto err;
  }

622
  /* Perform FULLTEXT search before all regular searches */
623
  init_ftfuncs(thd,test(order));
624

unknown's avatar
unknown committed
625 626 627 628 629 630 631 632 633 634 635 636 637
  /* 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";

    if (!(tmp_table =
	  create_tmp_table(thd,&join.tmp_table_param,all_fields,
			   ((!simple_group && !procedure &&
			     !(test_flags & TEST_NO_KEY_GROUP)) ?
			    group : (ORDER*) 0),
			   group ? 0 : select_distinct,
			   group && simple_group,
638
			   (order == 0 || skip_sort_order) &&
639
			   !(join.select_options & OPTION_FOUND_ROWS),
unknown's avatar
unknown committed
640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671
			   join.select_options)))
      goto err;					/* purecov: inspected */

    if (having && (join.sort_and_group || (tmp_table->distinct && !group)))
      join.having=having;

    /* if group or order on first table, sort first */
    if (group && simple_group)
    {
      DBUG_PRINT("info",("Sorting for group"));
      thd->proc_info="Sorting for group";
      if (create_sort_index(&join.join_tab[join.const_tables],group,
			    HA_POS_ERROR) ||
	  make_sum_func_list(&join,all_fields) ||
	  alloc_group_fields(&join,group))
	goto err;
      group=0;
    }
    else
    {
      if (make_sum_func_list(&join,all_fields))
	goto err;
      if (!group && ! tmp_table->distinct && order && simple_order)
      {
	DBUG_PRINT("info",("Sorting for order"));
	thd->proc_info="Sorting for order";
	if (create_sort_index(&join.join_tab[join.const_tables],order,
			      HA_POS_ERROR))
	  goto err;				/* purecov: inspected */
	order=0;
      }
    }
unknown's avatar
unknown committed
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688

    /*
      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 (tmp_table->distinct)
    {
      table_map used_tables= thd->used_tables;
      JOIN_TAB *join_tab=join.join_tab+join.tables-1;
      do
      {
	if (used_tables & join_tab->table->map)
	  break;
	join_tab->not_used_in_distinct=1;
      } while (join_tab-- != join.join_tab);
689 690 691 692 693 694 695
      /* Optimize "select distinct b from t1 order by key_part_1 limit #" */
      if (order && skip_sort_order)
      {
	(void) test_if_skip_sort_order(&join.join_tab[join.const_tables],
				       order, thd->select_limit,0);
	order=0;
      }
unknown's avatar
unknown committed
696 697 698
    }

    /* Copy data to the temporary table */
unknown's avatar
unknown committed
699
    thd->proc_info="Copying to tmp table";
700 701 702
    if ((tmp_error=do_select(&join,(List<Item> *) 0,tmp_table,0)))
    {
      error=tmp_error;
unknown's avatar
unknown committed
703
      goto err;					/* purecov: inspected */
704
    }
unknown's avatar
unknown committed
705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
    if (join.having)
      join.having=having=0;			// Allready done

    /* Change sum_fields reference to calculated fields in tmp_table */
    if (join.sort_and_group || tmp_table->group)
    {
      if (change_to_use_tmp_fields(all_fields))
	goto err;
      join.tmp_table_param.field_count+=join.tmp_table_param.sum_func_count+
	join.tmp_table_param.func_count;
      join.tmp_table_param.sum_func_count=join.tmp_table_param.func_count=0;
    }
    else
    {
      if (change_refs_to_tmp_fields(thd,all_fields))
	goto err;
      join.tmp_table_param.field_count+=join.tmp_table_param.func_count;
      join.tmp_table_param.func_count=0;
    }
    if (procedure)
      procedure->update_refs();
    if (tmp_table->group)
    {						// Already grouped
      if (!order && !no_order)
	order=group;				/* order by group */
      group=0;
    }

    /*
    ** If we have different sort & group then we must sort the data by group
    ** and copy it to another tmp table
unknown's avatar
unknown committed
736 737 738
    ** 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(...)).
unknown's avatar
unknown committed
739 740
    */

unknown's avatar
unknown committed
741 742 743
    if (group && (!test_if_subpart(group,order) || select_distinct) ||
	(select_distinct &&
	 join.tmp_table_param.using_indirect_summary_function))
unknown's avatar
unknown committed
744 745 746 747 748 749 750 751 752
    {					/* Must copy to another table */
      TABLE *tmp_table2;
      DBUG_PRINT("info",("Creating group table"));

      /* Free first data from old join */
      join_free(&join);
      if (make_simple_join(&join,tmp_table))
	goto err;
      calc_group_buffer(&join,group);
unknown's avatar
unknown committed
753 754 755 756
      count_field_types(&join.tmp_table_param,all_fields,
			select_distinct && !group);
      join.tmp_table_param.hidden_field_count=(all_fields.elements-
					       fields.elements);
unknown's avatar
unknown committed
757 758 759

      /* group data to new table */
      if (!(tmp_table2 = create_tmp_table(thd,&join.tmp_table_param,all_fields,
unknown's avatar
unknown committed
760 761 762
					  (ORDER*) 0,
					  select_distinct && !group,
					  1, 0,
unknown's avatar
unknown committed
763 764 765 766 767 768 769 770
					  join.select_options)))
	goto err;				/* purecov: inspected */
      if (group)
      {
	thd->proc_info="Creating sort index";
	if (create_sort_index(join.join_tab,group,HA_POS_ERROR) ||
	    alloc_group_fields(&join,group))
	{
unknown's avatar
unknown committed
771
	  free_tmp_table(thd,tmp_table2);	/* purecov: inspected */
unknown's avatar
unknown committed
772 773 774 775 776
	  goto err;				/* purecov: inspected */
	}
	group=0;
      }
      thd->proc_info="Copying to group table";
777
      tmp_error= -1;
unknown's avatar
unknown committed
778
      if (make_sum_func_list(&join,all_fields) ||
779
	  (tmp_error=do_select(&join,(List<Item> *) 0,tmp_table2,0)))
unknown's avatar
unknown committed
780
      {
781
	error=tmp_error;
unknown's avatar
unknown committed
782 783 784 785 786 787 788 789 790
	free_tmp_table(thd,tmp_table2);
	goto err;				/* purecov: inspected */
      }
      end_read_record(&join.join_tab->read_record);
      free_tmp_table(thd,tmp_table);
      join.const_tables=join.tables;		// Mark free for join_free()
      tmp_table=tmp_table2;
      join.join_tab[0].table=0;			// Table is freed

791
      if (change_to_use_tmp_fields(all_fields)) // No sum funcs anymore
unknown's avatar
unknown committed
792 793 794 795 796 797
	goto err;
      join.tmp_table_param.field_count+=join.tmp_table_param.sum_func_count;
      join.tmp_table_param.sum_func_count=0;
    }

    if (tmp_table->distinct)
798
      select_distinct=0;			/* Each row is unique */
unknown's avatar
unknown committed
799 800 801 802 803

    join_free(&join);				/* Free quick selects */
    if (select_distinct && ! group)
    {
      thd->proc_info="Removing duplicates";
804 805 806 807 808
      if (having)
	having->update_used_tables();
      if (remove_duplicates(&join,tmp_table,fields, having))
	goto err;				/* purecov: inspected */
      having=0;
unknown's avatar
unknown committed
809 810 811 812 813 814
      select_distinct=0;
    }
    tmp_table->reginfo.lock_type=TL_UNLOCK;
    if (make_simple_join(&join,tmp_table))
      goto err;
    calc_group_buffer(&join,group);
unknown's avatar
unknown committed
815
    count_field_types(&join.tmp_table_param,all_fields,0);
unknown's avatar
unknown committed
816 817 818 819 820 821
  }
  if (procedure)
  {
    if (procedure->change_columns(fields) ||
	result->prepare(fields))
      goto err;
unknown's avatar
unknown committed
822
    count_field_types(&join.tmp_table_param,all_fields,0);
unknown's avatar
unknown committed
823 824 825 826 827
  }
  if (join.group || join.tmp_table_param.sum_func_count ||
      (procedure && (procedure->flags & PROC_GROUP)))
  {
    alloc_group_fields(&join,group);
unknown's avatar
unknown committed
828
    setup_copy_fields(thd, &join.tmp_table_param,all_fields);
unknown's avatar
unknown committed
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
    if (make_sum_func_list(&join,all_fields) || thd->fatal_error)
      goto err; /* purecov: inspected */
  }
  if (group || order)
  {
    DBUG_PRINT("info",("Sorting for send_fields"));
    thd->proc_info="Sorting result";
    /* If we have already done the group, add HAVING to sorted table */
    if (having && ! group && ! join.sort_and_group)
    {
      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;

      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))
	    goto err;
	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)))
	    goto err;
	table->select_cond=table->select->cond;
	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(conds,"having after sort"););
      }
    }
    if (create_sort_index(&join.join_tab[join.const_tables],
			  group ? group : order,
			  (having || group ||
865 866
			   join.const_tables != join.tables - 1 ||
			   (join.select_options & OPTION_FOUND_ROWS)) ?
unknown's avatar
unknown committed
867 868 869 870 871 872 873 874
			  HA_POS_ERROR : thd->select_limit))
      goto err; /* purecov: inspected */
  }
  join.having=having;				// Actually a parameter
  thd->proc_info="Sending data";
  error=do_select(&join,&fields,NULL,procedure);

err:
875
  thd->limit_found_rows = join.send_records;
876
  thd->examined_row_count = join.examined_rows;
unknown's avatar
unknown committed
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
  thd->proc_info="end";
  join.lock=0;					// It's faster to unlock later
  join_free(&join);
  thd->proc_info="end2";			// QQ
  if (tmp_table)
    free_tmp_table(thd,tmp_table);
  thd->proc_info="end3";			// QQ
  delete select;
  delete_dynamic(&keyuse);
  delete procedure;
  thd->proc_info="end4";			// QQ
  DBUG_RETURN(error);
}

/*****************************************************************************
**	Create JOIN_TABS, make a guess about the table types,
**	Approximate how many records will be used in each table
*****************************************************************************/

static ha_rows get_quick_record_count(SQL_SELECT *select,TABLE *table,
unknown's avatar
unknown committed
897
				      key_map keys,ha_rows limit)
unknown's avatar
unknown committed
898 899 900 901 902 903 904
{
  int error;
  DBUG_ENTER("get_quick_record_count");
  if (select)
  {
    select->head=table;
    table->reginfo.impossible_range=0;
unknown's avatar
unknown committed
905
    if ((error=select->test_quick_select(keys,(table_map) 0,limit))
unknown's avatar
unknown committed
906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
	== 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 */
}


static bool
make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
921
		     DYNAMIC_ARRAY *keyuse_array)
unknown's avatar
unknown committed
922 923 924
{
  int error;
  uint i,table_count,const_count,found_ref,refs,key,const_ref,eq_part;
925
  table_map const_table_map,found_const_table_map,all_table_map;
unknown's avatar
unknown committed
926 927 928 929 930 931 932 933 934
  TABLE **table_vector;
  JOIN_TAB *stat,*stat_end,*s,**stat_ref;
  SQL_SELECT *select;
  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;
935 936
  stat=(JOIN_TAB*) join->thd->calloc(sizeof(JOIN_TAB)*table_count);
  stat_ref=(JOIN_TAB**) join->thd->alloc(sizeof(JOIN_TAB*)*MAX_TABLES);
937
  table_vector=(TABLE**) join->thd->alloc(sizeof(TABLE*)*(table_count*2));
unknown's avatar
unknown committed
938 939 940 941 942 943 944
  if (!stat || !stat_ref || !table_vector)
    DBUG_RETURN(1);				// Eom /* purecov: inspected */
  select=0;

  join->best_ref=stat_vector;

  stat_end=stat+table_count;
945
  const_table_map=found_const_table_map=all_table_map=0;
unknown's avatar
unknown committed
946 947 948 949 950 951 952 953 954 955 956 957 958
  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;
959
    s->join=join;
960
    s->info=0;					// For describe
unknown's avatar
unknown committed
961 962
    if ((s->on_expr=tables->on_expr))
    {
963
      /* Left join */
unknown's avatar
unknown committed
964 965
      if (!table->file->records)
      {						// Empty table
966
	s->key_dependent=s->dependent=0;	// Ignore LEFT JOIN depend.
unknown's avatar
unknown committed
967 968 969
	set_position(join,const_count++,s,(KEYUSE*) 0);
	continue;
      }
unknown's avatar
unknown committed
970 971
      s->key_dependent=s->dependent=
	s->on_expr->used_tables() & ~(table->map);
972 973 974 975
      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;
unknown's avatar
unknown committed
976 977 978 979 980 981 982 983
      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;
unknown's avatar
unknown committed
984
    if ((table->system || table->file->records <= 1) && ! s->dependent &&
985
	!(table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
unknown's avatar
unknown committed
986
        !table->fulltext_searched)
unknown's avatar
unknown committed
987 988 989 990 991
    {
      set_position(join,const_count++,s,(KEYUSE*) 0);
    }
  }
  stat_vector[i]=0;
992
  join->outer_join=outer_join;
unknown's avatar
unknown committed
993 994

  /*
995 996 997 998
    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.
unknown's avatar
unknown committed
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030
  */
  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)
1031
    if (update_ref_and_keys(join->thd,keyuse_array,stat,join->tables,
1032
                            conds,~outer_join))
unknown's avatar
unknown committed
1033 1034
      DBUG_RETURN(1);

1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
  /* Read tables with 0 or 1 rows (system tables) */
  join->const_table_map=const_table_map;

  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;
  }

unknown's avatar
unknown committed
1055
  /* loop until no more const tables are found */
1056
  int ref_changed;
unknown's avatar
unknown committed
1057 1058
  do
  {
1059
    ref_changed = 0;
unknown's avatar
unknown committed
1060
    found_ref=0;
1061 1062 1063 1064 1065 1066 1067

    /*
      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++)
unknown's avatar
unknown committed
1068
    {
1069
      TABLE *table=s->table;
unknown's avatar
unknown committed
1070 1071
      if (s->dependent)				// If dependent on some table
      {
1072 1073
	// All dep. must be constants
	if (s->dependent & ~(join->const_table_map))
unknown's avatar
unknown committed
1074
	  continue;
1075
	if (table->file->records <= 1L &&
1076
	    !(table->file->table_flags() & HA_NOT_EXACT_COUNT))
unknown's avatar
unknown committed
1077
	{					// system table
1078
	  int tmp;
unknown's avatar
unknown committed
1079
	  s->type=JT_SYSTEM;
1080
	  join->const_table_map|=table->map;
unknown's avatar
unknown committed
1081
	  set_position(join,const_count++,s,(KEYUSE*) 0);
1082 1083 1084 1085 1086 1087 1088
	  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;
unknown's avatar
unknown committed
1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106
	  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 ?

	  refs=const_ref=eq_part=0;
	  do
	  {
	    if (keyuse->val->type() != Item::NULL_ITEM)
	    {
1107
	      if (!((~join->const_table_map) & keyuse->used_tables))
unknown's avatar
unknown committed
1108 1109 1110 1111 1112 1113 1114 1115 1116
		const_ref|= (key_map) 1 << keyuse->keypart;
	      else
		refs|=keyuse->used_tables;
	      eq_part|= (uint) 1 << keyuse->keypart;
	    }
	    keyuse++;
	  } while (keyuse->table == table && keyuse->key == key);

	  if (eq_part == PREV_BITS(uint,table->key_info[key].key_parts) &&
unknown's avatar
unknown committed
1117 1118
	      (table->key_info[key].flags & HA_NOSAME) &&
              !table->fulltext_searched)
unknown's avatar
unknown committed
1119 1120 1121
	  {
	    if (const_ref == eq_part)
	    {					// Found everything for ref.
1122 1123
	      int tmp;
	      ref_changed = 1;
unknown's avatar
unknown committed
1124
	      s->type=JT_CONST;
1125
	      join->const_table_map|=table->map;
unknown's avatar
unknown committed
1126
	      set_position(join,const_count++,s,start_keyuse);
1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
	      if (create_ref_for_key(join, s, start_keyuse,
				     join->const_table_map))
		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;
unknown's avatar
unknown committed
1138 1139 1140 1141 1142 1143 1144 1145
	      break;
	    }
	    else
	      found_ref|= refs;		// Table is const if all refs are const
	  }
	}
      }
    }
1146
  } while (join->const_table_map & found_ref && ref_changed);
unknown's avatar
unknown committed
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159

  /* 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;
1160
    s->read_time=(ha_rows) s->table->file->scan_time();
unknown's avatar
unknown committed
1161

1162 1163 1164 1165
    /*
      Set a max range of how many seeks we can expect when using keys
      This was (s->read_time*5), but this was too low with small rows
    */
unknown's avatar
unknown committed
1166
    s->worst_seeks= (double) s->found_records / 5;
unknown's avatar
unknown committed
1167 1168 1169 1170 1171 1172 1173 1174 1175
    if (s->worst_seeks < 2.0)			// Fix for small tables
      s->worst_seeks=2.0;

    /* if (s->type == JT_EQ_REF)
      continue; */
    if (s->const_keys)
    {
      ha_rows records;
      if (!select)
1176 1177
	select=make_select(s->table, join->const_table_map,
			   join->const_table_map,
unknown's avatar
unknown committed
1178
			   and_conds(conds,s->on_expr),&error);
unknown's avatar
unknown committed
1179 1180
      records=get_quick_record_count(select,s->table, s->const_keys,
				     join->row_limit);
unknown's avatar
unknown committed
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197
      s->quick=select->quick;
      s->needed_reg=select->needed_reg;
      select->quick=0;
      if (records != HA_POS_ERROR)
      {
	s->found_records=records;
	s->read_time= (ha_rows) (s->quick ? s->quick->read_time : 0.0);
      }
    }
  }
  delete select;

  /* 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;
1198
  join->found_const_table_map=found_const_table_map;
unknown's avatar
unknown committed
1199 1200

  if (join->const_tables != join->tables)
1201
    find_best_combination(join,all_table_map & ~join->const_table_map);
unknown's avatar
unknown committed
1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237
  else
  {
    memcpy((gptr) join->best_positions,(gptr) join->positions,
	   sizeof(POSITION)*join->const_tables);
    join->best_read=1.0;
  }
  DBUG_RETURN(get_best_combination(join));
}


/*****************************************************************************
**	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
*****************************************************************************/

typedef struct key_field_t {		// Used when finding key fields
  Field		*field;
  Item		*val;			// May be empty if diff constant
  uint		level,const_level;	// QQ: Remove const_level
  bool		eq_func;
  bool		exists_optimize;
} KEY_FIELD;


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

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)
unknown's avatar
unknown committed
1238
    return start;				// No new fields, skip all
unknown's avatar
unknown committed
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250

  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())
	{
1251
	  if (old->val->eq(new_fields->val, old->field->binary()))
unknown's avatar
unknown committed
1252 1253 1254 1255 1256
	  {
	    old->level=old->const_level=and_level;
	    old->exists_optimize&=new_fields->exists_optimize;
	  }
	}
1257 1258
	else if (old->val->eq(new_fields->val, old->field->binary()) &&
		 old->eq_func && new_fields->eq_func)
unknown's avatar
unknown committed
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299
	{
	  old->level=old->const_level=and_level;
	  old->exists_optimize&=new_fields->exists_optimize;
	}
	else					// Impossible; remove it
	{
	  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 ;)
  {
    if (old->level != and_level && old->const_level != and_level)
    {						// Not used in all levels
      if (old == --first_free)
	break;
      *old= *first_free;			// Remove old value
      continue;
    }
    old++;
  }
  return first_free;
}


static void
add_key_field(KEY_FIELD **key_fields,uint and_level,
	      Field *field,bool eq_func,Item *value,
	      table_map usable_tables)
{
  bool exists_optimize=0;
  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)
unknown's avatar
unknown committed
1300
      return;					// Not a key. Skip it
unknown's avatar
unknown committed
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
    exists_optimize=1;
  }
  else
  {
    table_map used_tables=0;
    if (value && (used_tables=value->used_tables()) &
	(field->table->map | RAND_TABLE_BIT))
      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
      exists_optimize=1;
    }
    else
    {
      JOIN_TAB *stat=field->table->reginfo.join_tab;
unknown's avatar
unknown committed
1319 1320 1321
      key_map possible_keys= (field->key_start &
			      field->table->keys_in_use_for_query);
      stat[0].keys|= possible_keys;		// Add possible keys
unknown's avatar
unknown committed
1322 1323 1324

      if (!value)
      {						// Probably BETWEEN or IN
unknown's avatar
unknown committed
1325
	stat[0].const_keys |= possible_keys;
unknown's avatar
unknown committed
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338
	return;					// Can't be used as eq key
      }

      /* 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
      */
      stat[0].key_dependent|=used_tables;
      if (value->const_item())
unknown's avatar
unknown committed
1339
	stat[0].const_keys |= possible_keys;
unknown's avatar
unknown committed
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365

      /* 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 */
      if (!eq_func ||
	  field->result_type() == STRING_RESULT &&
	  value->result_type() != STRING_RESULT &&
	  field->cmp_type() != value->result_type())
	return;
    }
  }
  /* Store possible eq field */
  (*key_fields)->field=field;
  (*key_fields)->eq_func=eq_func;
  (*key_fields)->val=value;
  (*key_fields)->level=(*key_fields)->const_level=and_level;
  (*key_fields)->exists_optimize=exists_optimize;
  (*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)
  {
unknown's avatar
unknown committed
1366
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
unknown's avatar
unknown committed
1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502
    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++)
      {
	if (org_key_fields->const_level == org_key_fields->level)
	  org_key_fields->const_level=org_key_fields->level= *and_level;
	else
	  org_key_fields->const_level= *and_level;
      }
    }
    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:
    if (cond_func->key_item()->type() == Item::FIELD_ITEM)
      add_key_field(key_fields,*and_level,
		    ((Item_field*) (cond_func->key_item()))->field,
		    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);

    if (cond_func->arguments()[0]->type() == Item::FIELD_ITEM)
    {
      add_key_field(key_fields,*and_level,
		    ((Item_field*) (cond_func->arguments()[0]))->field,
		    equal_func,
		    (cond_func->arguments()[1]),usable_tables);
    }
    if (cond_func->arguments()[1]->type() == Item::FIELD_ITEM &&
	cond_func->functype() != Item_func::LIKE_FUNC)
    {
      add_key_field(key_fields,*and_level,
		    ((Item_field*) (cond_func->arguments()[1]))->field,
		    equal_func,
		    (cond_func->arguments()[0]),usable_tables);
    }
    break;
  }
  case Item_func::OPTIMIZE_NULL:
    /* column_name IS [NOT] NULL */
    if (cond_func->arguments()[0]->type() == Item::FIELD_ITEM)
    {
      add_key_field(key_fields,*and_level,
		    ((Item_field*) (cond_func->arguments()[0]))->field,
		    cond_func->functype() == Item_func::ISNULL_FUNC,
		    new Item_null, usable_tables);
    }
    break;
  }
  return;
}

/*
** Add all keys with uses 'field' for some keypart
** If field->and_level != and_level then only mark key_part as const_part
*/

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;

  if (key_field->eq_func && !key_field->exists_optimize)
  {
    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;
	  keyuse.used_tables=key_field->val->used_tables();
	  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;
}

static void
add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
            JOIN_TAB *stat,COND *cond,table_map usable_tables)
{
1503
  Item_func_match *cond_func=NULL;
unknown's avatar
unknown committed
1504

1505 1506 1507
  if (!cond)
    return;

1508 1509
  if (cond->type() == Item::FUNC_ITEM)
  {
1510 1511 1512
    Item_func *func=(Item_func *)cond;
    Item_func::Functype functype=  func->functype();
    if (functype == Item_func::FT_FUNC)
1513
      cond_func=(Item_func_match *)cond;
1514 1515 1516 1517 1518 1519
    else if (func->arg_count == 2)
    {
      Item_func *arg0=(Item_func *)(func->arguments()[0]),
                *arg1=(Item_func *)(func->arguments()[1]);
      if ((functype == Item_func::GE_FUNC ||
           functype == Item_func::GT_FUNC)  &&
1520
           arg0->type() == Item::FUNC_ITEM          &&
1521
           arg0->functype() == Item_func::FT_FUNC   &&
1522
           arg1->const_item() && arg1->val()>0)
1523 1524 1525 1526 1527
        cond_func=(Item_func_match *) arg0;
      else if ((functype == Item_func::LE_FUNC ||
                functype == Item_func::LT_FUNC)  &&
                arg1->type() == Item::FUNC_ITEM          &&
                arg1->functype() == Item_func::FT_FUNC   &&
1528
                arg0->const_item() && arg0->val()>0)
1529 1530
        cond_func=(Item_func_match *) arg1;
    }
1531 1532 1533
  }
  else if (cond->type() == Item::COND_ITEM)
  {
unknown's avatar
unknown committed
1534
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
1535 1536 1537 1538

    if (((Item_cond*) cond)->functype() == Item_func::COND_AND_FUNC)
    {
      Item *item;
1539
      /*
1540
         I'm (Sergei) too lazy to implement proper recursive descent here,
1541 1542 1543
         and anyway, nobody will use such a stupid queries
         that will require it :-)
         May be later...
1544
      */
1545
      while ((item=li++))
1546
      {
1547 1548 1549 1550 1551 1552
        if (item->type() == Item::FUNC_ITEM &&
            ((Item_func *)item)->functype() == Item_func::FT_FUNC)
        {
          cond_func=(Item_func_match *)item;
          break;
        }
1553
      }
1554 1555 1556
    }
  }

1557
  if (!cond_func || cond_func->key == NO_SUCH_KEY)
1558
    return;
unknown's avatar
unknown committed
1559 1560 1561 1562

  KEYUSE keyuse;

  keyuse.table= cond_func->table;
1563
  keyuse.val =  cond_func;
unknown's avatar
unknown committed
1564 1565 1566
  keyuse.key =  cond_func->key;
#define FT_KEYPART   (MAX_REF_PARTS+10)
  keyuse.keypart=FT_KEYPART;
1567
  keyuse.used_tables=cond_func->key_item()->used_tables();
unknown's avatar
unknown committed
1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
  VOID(insert_dynamic(keyuse_array,(gptr) &keyuse));
}

static int
sort_keyuse(KEYUSE *a,KEYUSE *b)
{
  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);
  return test(a->used_tables) - test(b->used_tables);	// Place const first
}


/*
** 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.
*/

static bool
1591
update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
1592
		    uint tables, COND *cond, table_map normal_tables)
unknown's avatar
unknown committed
1593 1594 1595 1596 1597 1598 1599
{
  uint	and_level,i,found_eq_constant;

  {
    KEY_FIELD *key_fields,*end;

    if (!(key_fields=(KEY_FIELD*)
unknown's avatar
unknown committed
1600
	  thd->alloc(sizeof(key_fields[0])*(thd->cond_count+1)*2)))
unknown's avatar
unknown committed
1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
      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++)
    {
      if (join_tab[i].on_expr)
      {
	add_key_fields(join_tab,&end,&and_level,join_tab[i].on_expr,
		       join_tab[i].table->map);
      }
    }
1613
    if (my_init_dynamic_array(keyuse,sizeof(KEYUSE),20,64))
unknown's avatar
unknown committed
1614 1615 1616 1617 1618 1619
      return TRUE;
    /* fill keyuse with found key parts */
    for (KEY_FIELD *field=key_fields ; field != end ; field++)
      add_key_part(keyuse,field);
  }

1620
  if (thd->lex.select->ftfunc_list.elements)
unknown's avatar
unknown committed
1621 1622 1623 1624 1625 1626 1627
  {
    add_ft_keys(keyuse,join_tab,cond,normal_tables);
  }

  /*
  ** remove ref if there is a keypart which is a ref and a const.
  ** remove keyparts without previous keyparts.
1628
  ** Special treatment for ft-keys.
unknown's avatar
unknown committed
1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
  */
  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)
1646
	use->table->const_key_parts[use->key] |=
unknown's avatar
unknown committed
1647 1648 1649
	  (key_part_map) 1 << use->keypart;
      if (use->keypart != FT_KEYPART)
      {
1650 1651 1652 1653 1654 1655 1656 1657
	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;
unknown's avatar
unknown committed
1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 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 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
      }

      *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;
}


/*****************************************************************************
**	Go through all combinations of not marked tables and find the one
**	which uses least records
*****************************************************************************/

/* 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];
  for ( ;next != table ; pos++)
  {
    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)
{
  ulong rec;
  double tmp;

  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;
1751
      uint best_max_key_part=0;
unknown's avatar
unknown committed
1752 1753 1754 1755 1756 1757

      if (s->keyuse)
      {						/* Use key if possible */
	TABLE *table=s->table;
	KEYUSE *keyuse,*start_key=0;
	double best_records=DBL_MAX;
1758
	uint max_key_part=0;
unknown's avatar
unknown committed
1759 1760

	/* Test how we can use keys */
1761
	rec= s->records/MATCHING_ROWS_IN_OTHER_TABLE;  /* Assumed records/key */
unknown's avatar
unknown committed
1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775
	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);

	  start_key=keyuse;
	  do
	  {
            uint keypart=keyuse->keypart;
	    do
	    {
1776
              if (!ft_key)
unknown's avatar
unknown committed
1777
              {
1778 1779
		table_map map;
		if (!(rest_tables & keyuse->used_tables))
unknown's avatar
unknown committed
1780
		{
1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
		  found_part|= (key_part_map) 1 << keypart;
		  found_ref|= keyuse->used_tables;
		}
		/*
		** 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 and to avoid bad matches,
		** we don't make rec less than 100.
		*/
		if (keyuse->used_tables &
		    (map=(keyuse->used_tables & ~join->const_table_map)))
		{
		  uint tablenr;
		  for (tablenr=0 ; ! (map & 1) ; map>>=1, tablenr++) ;
		  if (map == 1)			// Only one table
		  {
		    TABLE *tmp_table=join->all_tables[tablenr];
		    if (rec > tmp_table->file->records && rec > 100)
		      rec=max(tmp_table->file->records,100);
		  }
unknown's avatar
unknown committed
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836
		}
              }
	      keyuse++;
	    } while (keyuse->table == table && keyuse->key == key &&
		     keyuse->keypart == keypart);
	  } while (keyuse->table == table && keyuse->key == key);

	  /*
	  ** Assume that that each key matches a proportional part of table.
	  */
          if (!found_part && !ft_key)
	    continue;				// Nothing usable found
	  if (rec == 0)
	    rec=1L;				// Fix for small tables

          /*
          ** ft-keys require special treatment
          */
          if (ft_key)
          {
            /*
            ** Really, there should be records=0.0 (yes!)
            ** but 1.0 would be probably safer
            */
            tmp=prev_record_reads(join,found_ref);
            records=1.0;
          }
          else
          {
	  /*
	  ** Check if we found full key
	  */
	  if (found_part == PREV_BITS(uint,keyinfo->key_parts))
	  {				/* use eq key */
1837
	    max_key_part= (uint) ~0;
unknown's avatar
unknown committed
1838 1839 1840 1841 1842 1843 1844
	    if ((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY)) == HA_NOSAME)
	    {
	      tmp=prev_record_reads(join,found_ref);
	      records=1.0;
	    }
	    else
	    {
1845 1846
	      if (!found_ref)
	      {					// We found a const key
unknown's avatar
unknown committed
1847 1848 1849
		if (table->quick_keys & ((key_map) 1 << key))
		  records= (double) table->quick_rows[key];
		else
1850
		  records= (double) s->records/rec; // quick_range couldn't use key!
unknown's avatar
unknown committed
1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868
	      }
	      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
		}
	      }
	      if (table->used_keys & ((key_map) 1 << key))
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
unknown's avatar
unknown committed
1869
		  (keyinfo->key_length+table->file->ref_length)+1;
unknown's avatar
unknown committed
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
		tmp=(record_count*(records+keys_per_block-1)/
		     keys_per_block);
	      }
	      else
		tmp=record_count*min(records,s->worst_seeks);
	    }
	  }
	  else
	  {
	    /*
	    ** 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)
	    */
1884
	    if ((found_part & 1) &&
1885
		!(table->file->index_flags(key) & HA_ONLY_WHOLE_INDEX))
unknown's avatar
unknown committed
1886
	    {
1887
	      max_key_part=max_part_bit(found_part);
unknown's avatar
unknown committed
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938
	      /* Check if quick_range could determinate how many rows we
		 will match */

	      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
		{
		  /*
		  ** Assume that the first key part matches 1% of the file
		  ** and that the hole key matches 10 (dupplicates) or 1
		  ** (unique) records.
		  ** Assume also that more key matches proportionally more
		  ** records
		  ** This gives the formula:
		  ** records= (x * (b-a) + a*c-b)/(c-1)
		  **
		  ** 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)
		  */
		  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;
		}
	      }
	      if (table->used_keys & ((key_map) 1 << key))
	      {
		/* we can use only index tree */
		uint keys_per_block= table->file->block_size/2/
unknown's avatar
unknown committed
1939
		  (keyinfo->key_length+table->file->ref_length)+1;
unknown's avatar
unknown committed
1940 1941 1942 1943 1944 1945 1946 1947
		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
	  }
1948
          } /* not ft_key */
unknown's avatar
unknown committed
1949 1950 1951 1952 1953 1954
	  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;
1955
	    best_max_key_part=max_key_part;
unknown's avatar
unknown committed
1956 1957 1958 1959
	  }
	}
	records=best_records;
      }
1960 1961 1962 1963

      /*
	Don't test table scan if it can't be better.
	Prefer key lookup if we would use the same key for scanning.
1964 1965 1966 1967 1968

	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.
1969 1970 1971
      */
      if ((records >= s->found_records || best > s->read_time) &&
	  !(s->quick && best_key && s->quick->index == best_key->key &&
1972
	    best_max_key_part >= s->table->quick_key_parts[best_key->key]) &&
1973
	  !((s->table->file->table_flags() & HA_TABLE_SCAN_ON_INDEX) &&
1974
	    s->table->used_keys && best_key))
unknown's avatar
unknown committed
1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
      {						// Check full join
	if (s->on_expr)
	{
	  tmp=s->found_records;			// Can't use read cache
	}
	else
	{
	  tmp=(double) s->read_time;
	  /* Calculate time to read through cache */
	  tmp*=(1.0+floor((double) cache_record_length(join,idx)*
			  record_count/(double) join_buff_size));
	}
	if (best == DBL_MAX ||
	    (tmp  + record_count/(double) TIME_FOR_COMPARE*s->found_records <
	     best + record_count/(double) TIME_FOR_COMPARE*records))
	{
1991 1992 1993 1994
	  /*
	    If the table has a range (s->quick is set) make_join_select()
	    will ensure that this will be used
	  */
unknown's avatar
unknown committed
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039
	  best=tmp;
	  records=s->found_records;
	  best_key=0;
	}
      }
      join->positions[idx].records_read=(double) records;
      join->positions[idx].key=best_key;
      join->positions[idx].table= s;
      if (!best_key && idx == join->const_tables &&
	  s->table == join->sort_by_table)
	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);
	swap(JOIN_TAB*,join->best_ref[idx],*pos);
      }
      if (join->select_options & SELECT_STRAIGHT_JOIN)
	break;				// Don't test all combinations
    }
  }
}


/*
** Find how much space the prevous read not const tables takes in cache
*/

2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
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;
}


unknown's avatar
unknown committed
2075 2076 2077
static uint
cache_record_length(JOIN *join,uint idx)
{
2078
  uint length=0;
unknown's avatar
unknown committed
2079
  JOIN_TAB **pos,**end;
2080
  THD *thd=join->thd;
unknown's avatar
unknown committed
2081 2082 2083 2084 2085 2086

  for (pos=join->best_ref+join->const_tables,end=join->best_ref+idx ;
       pos != end ;
       pos++)
  {
    JOIN_TAB *join_tab= *pos;
2087 2088
    if (!join_tab->used_fieldlength)		/* Not calced yet */
      calc_used_field_length(thd, join_tab);
unknown's avatar
unknown committed
2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118
    length+=join_tab->used_fieldlength;
  }
  return length;
}


static double
prev_record_reads(JOIN *join,table_map found_ref)
{
  double found=1.0;

  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;
}


/*****************************************************************************
**	Set up join struct according to best position.
*****************************************************************************/

static bool
get_best_combination(JOIN *join)
{
2119
  uint i,tablenr;
unknown's avatar
unknown committed
2120 2121 2122 2123
  table_map used_tables;
  JOIN_TAB *join_tab,*j;
  KEYUSE *keyuse;
  uint table_count;
2124
  THD *thd=join->thd;
unknown's avatar
unknown committed
2125 2126 2127

  table_count=join->tables;
  if (!(join->join_tab=join_tab=
2128
	(JOIN_TAB*) thd->alloc(sizeof(JOIN_TAB)*table_count)))
unknown's avatar
unknown committed
2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
    return TRUE;

  join->full_join=0;

  used_tables=0;
  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
2143 2144 2145 2146 2147
    if (j->type == JT_CONST)
      continue;					// Handled in make_join_stat..

    j->ref.key = -1;
    j->ref.key_parts=0;
unknown's avatar
unknown committed
2148 2149 2150 2151 2152 2153 2154 2155 2156

    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;
    }
2157 2158 2159
    else if (create_ref_for_key(join, j, keyuse, used_tables))
      return TRUE;				// Something went wrong
  }
unknown's avatar
unknown committed
2160

2161 2162 2163 2164 2165
  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;
}
2166

unknown's avatar
unknown committed
2167

2168 2169 2170 2171 2172 2173 2174 2175 2176
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;
2177

2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198
  /*
  ** Use best key from find_best
  */
  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;
    do
    {
      if (!((~used_tables) & keyuse->used_tables))
unknown's avatar
unknown committed
2199
      {
2200
	if (keyparts == keyuse->keypart)
unknown's avatar
unknown committed
2201
	{
2202 2203
	  keyparts++;
	  length+=keyinfo->key_part[keyuse->keypart].store_length;
unknown's avatar
unknown committed
2204 2205
	}
      }
2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258
      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;

  store_key **ref_key=j->ref.key_copy;
  byte *key_buff=j->ref.key_buff;
  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
	store_key_item *tmp=new store_key_item(thd,
					       keyinfo->key_part[i].field,
					       (char*)key_buff +
					       maybe_null,
					       maybe_null ?
					       (char*) key_buff : 0,
					       keyinfo->key_part[i].length,
					       keyuse->val);
	if (thd->fatal_error)
unknown's avatar
unknown committed
2259
	{
2260
	  return TRUE;
unknown's avatar
unknown committed
2261
	}
2262
	tmp->copy();
unknown's avatar
unknown committed
2263 2264
      }
      else
2265 2266 2267 2268 2269
	*ref_key++= get_store_key(thd,
				  keyuse,join->const_table_map,
				  &keyinfo->key_part[i],
				  (char*) key_buff,maybe_null);
      key_buff+=keyinfo->key_part[i].store_length;
unknown's avatar
unknown committed
2270
    }
2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289
  } /* not ftkey */
  *ref_key=0;				// end_marker
  if (j->type == JT_FT)  /* no-op */;
  else if (j->type == JT_CONST)
    j->table->const_table=1;
  else if (((keyinfo->flags & (HA_NOSAME | HA_NULL_PART_KEY))
	    != HA_NOSAME) ||
	   keyparts != keyinfo->key_parts)
    j->type=JT_REF;				/* Must read with repeat */
  else if (ref_key == j->ref.key_copy)
  {						/* Should never be reached */
    /*
      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;
unknown's avatar
unknown committed
2290
  }
2291 2292
  else
    j->type=JT_EQ_REF;
unknown's avatar
unknown committed
2293 2294 2295 2296
  return 0;
}


2297

unknown's avatar
unknown committed
2298
static store_key *
unknown's avatar
unknown committed
2299 2300
get_store_key(THD *thd, KEYUSE *keyuse, table_map used_tables,
	      KEY_PART_INFO *key_part, char *key_buff, uint maybe_null)
unknown's avatar
unknown committed
2301 2302 2303
{
  if (!((~used_tables) & keyuse->used_tables))		// if const item
  {
unknown's avatar
unknown committed
2304 2305
    return new store_key_const_item(thd,
				    key_part->field,
unknown's avatar
unknown committed
2306 2307 2308 2309 2310 2311
				    key_buff + maybe_null,
				    maybe_null ? key_buff : 0,
				    key_part->length,
				    keyuse->val);
  }
  else if (keyuse->val->type() == Item::FIELD_ITEM)
unknown's avatar
unknown committed
2312 2313
    return new store_key_field(thd,
			       key_part->field,
unknown's avatar
unknown committed
2314 2315 2316 2317 2318
			       key_buff + maybe_null,
			       maybe_null ? key_buff : 0,
			       key_part->length,
			       ((Item_field*) keyuse->val)->field,
			       keyuse->val->full_name());
unknown's avatar
unknown committed
2319 2320
  return new store_key_item(thd,
			    key_part->field,
unknown's avatar
unknown committed
2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
			    key_buff + maybe_null,
			    maybe_null ? key_buff : 0,
			    key_part->length,
			    keyuse->val);
}

/*
** 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.
*/

bool
store_val_in_field(Field *field,Item *item)
{
  THD *thd=current_thd;
  ulong cuted_fields=thd->cuted_fields;
  thd->count_cuted_fields=1;
  item->save_in_field(field);
  thd->count_cuted_fields=0;
  return cuted_fields != thd->cuted_fields;
}


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

2350 2351
  if (!(tableptr=(TABLE**) join->thd->alloc(sizeof(TABLE*))) ||
      !(join_tab=(JOIN_TAB*) join->thd->alloc(sizeof(JOIN_TAB))))
unknown's avatar
unknown committed
2352 2353 2354 2355 2356 2357
    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;
unknown's avatar
unknown committed
2358 2359 2360
  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;
unknown's avatar
unknown committed
2361 2362
  join->first_record=join->sort_and_group=0;
  join->sum_funcs=0;
unknown's avatar
unknown committed
2363
  join->send_records=(ha_rows) 0;
unknown's avatar
unknown committed
2364
  join->group=0;
2365
  join->do_send_rows = 1;
2366
  join->row_limit=join->thd->select_limit;
unknown's avatar
unknown committed
2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377

  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;
unknown's avatar
unknown committed
2378 2379
  join_tab->not_used_in_distinct=0;
  join_tab->read_first_record= join_init_read_record;
2380
  join_tab->join=join;
unknown's avatar
unknown committed
2381
  bzero((char*) &join_tab->read_record,sizeof(join_tab->read_record));
unknown's avatar
unknown committed
2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401
  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())
2402 2403
      {
	DBUG_PRINT("info",("Found impossible WHERE condition"));
unknown's avatar
unknown committed
2404
	DBUG_RETURN(1);				// Impossible const condition
2405
      }
unknown's avatar
unknown committed
2406 2407 2408 2409 2410 2411
    }
    used_tables=(select->const_tables=join->const_table_map) | RAND_TABLE_BIT;
    for (uint i=join->const_tables ; i < join->tables ; i++)
    {
      JOIN_TAB *tab=join->join_tab+i;
      table_map current_map= tab->table->map;
2412
      bool use_quick_range=0;
unknown's avatar
unknown committed
2413
      used_tables|=current_map;
2414 2415

      if (tab->type == JT_REF && tab->quick &&
unknown's avatar
unknown committed
2416
	  (uint) tab->ref.key == tab->quick->index &&
2417 2418 2419 2420 2421 2422 2423 2424 2425 2426
	  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.
	join->best_positions[i].records_read=tab->quick->records;
      }

unknown's avatar
unknown committed
2427
      COND *tmp=make_cond_for_table(cond,used_tables,current_map);
2428 2429 2430 2431 2432 2433 2434 2435
      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
      }
unknown's avatar
unknown committed
2436 2437 2438 2439
      if (tmp)
      {
	DBUG_EXECUTE("where",print_where(tmp,tab->table->table_name););
	SQL_SELECT *sel=tab->select=(SQL_SELECT*)
2440
	  join->thd->memdup((gptr) select, sizeof(SQL_SELECT));
unknown's avatar
unknown committed
2441 2442 2443 2444 2445 2446
	if (!sel)
	  DBUG_RETURN(1);			// End of memory
	tab->select_cond=sel->cond=tmp;
	sel->head=tab->table;
	if (tab->quick)
	{
2447 2448
	  /* Use quick key read if it's a constant and it's not used
	     with key reading */
2449 2450
	  if (tab->needed_reg == 0 && tab->type != JT_EQ_REF
	      && tab->type != JT_FT && (tab->type != JT_REF ||
unknown's avatar
unknown committed
2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468
	       (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);
	}
2469
	else if (tab->type == JT_ALL && ! use_quick_range)
unknown's avatar
unknown committed
2470 2471 2472 2473 2474 2475
	{
	  if (tab->const_keys &&
	      tab->table->reginfo.impossible_range)
	    DBUG_RETURN(1);				// Impossible range
	  /*
	    We plan to scan all rows.
2476 2477 2478
	    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
unknown's avatar
unknown committed
2479 2480 2481
	  */

	  if ((tab->keys & ~ tab->const_keys && i > 0) ||
2482 2483 2484
	      (tab->const_keys && i == join->const_tables &&
	       join->thd->select_limit < join->best_positions[i].records_read &&
	       !(join->select_options & OPTION_FOUND_ROWS)))
unknown's avatar
unknown committed
2485
	  {
2486 2487 2488
	    /* Join with outer join condition */
	    COND *orig_cond=sel->cond;
	    sel->cond=and_conds(sel->cond,tab->on_expr);
unknown's avatar
unknown committed
2489 2490
	    if (sel->test_quick_select(tab->keys,
				       used_tables & ~ current_map,
2491 2492 2493 2494
				       (join->select_options &
					OPTION_FOUND_ROWS ?
					HA_POS_ERROR :
					join->thd->select_limit)) < 0)
2495 2496
	      DBUG_RETURN(1);				// Impossible range
	    sel->cond=orig_cond;
unknown's avatar
unknown committed
2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520
	  }
	  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;
	    sel->read_tables= used_tables;
	  }
	  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"););
2521 2522
	      tab->cache.select=(SQL_SELECT*)
		join->thd->memdup((gptr) sel, sizeof(SQL_SELECT));
unknown's avatar
unknown committed
2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538
	      tab->cache.select->cond=tmp;
	      tab->cache.select->read_tables=join->const_table_map;
	    }
	  }
	}
      }
    }
  }
  DBUG_RETURN(0);
}


static void
make_join_readinfo(JOIN *join,uint options)
{
  uint i;
unknown's avatar
unknown committed
2539
  SELECT_LEX *select_lex = &(join->thd->lex.select_lex);
unknown's avatar
unknown committed
2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561
  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;
2562 2563 2564 2565 2566
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
unknown's avatar
unknown committed
2567 2568 2569 2570 2571
      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;
unknown's avatar
unknown committed
2572 2573
      if (table->used_keys & ((key_map) 1 << tab->ref.key) &&
	  !table->no_keyread)
unknown's avatar
unknown committed
2574 2575 2576 2577 2578 2579 2580
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
      break;
    case JT_REF:
      table->status=STATUS_NO_RECORD;
2581 2582 2583 2584 2585
      if (tab->select)
      {
	delete tab->select->quick;
	tab->select->quick=0;
      }
unknown's avatar
unknown committed
2586 2587 2588 2589
      delete tab->quick;
      tab->quick=0;
      table->file->index_init(tab->ref.key);
      tab->read_first_record= join_read_always_key;
2590
      tab->read_record.read_record= join_read_next_same;
unknown's avatar
unknown committed
2591 2592
      if (table->used_keys & ((key_map) 1 << tab->ref.key) &&
	  !table->no_keyread)
unknown's avatar
unknown committed
2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608
      {
	table->key_read=1;
	table->file->extra(HA_EXTRA_KEYREAD);
      }
      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:
      /*
      ** if previous table use cache
      */
      table->status=STATUS_NO_RECORD;
unknown's avatar
unknown committed
2609
      if (i != join->const_tables && !(options & SELECT_NO_JOIN_CACHE) &&
unknown's avatar
unknown committed
2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620
	  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)
2621
      {
unknown's avatar
unknown committed
2622
	select_lex->options|=QUERY_NO_GOOD_INDEX_USED;
unknown's avatar
unknown committed
2623
	tab->read_first_record= join_init_quick_read_record;
2624 2625
	statistic_increment(select_range_check_count, &LOCK_status);
      }
unknown's avatar
unknown committed
2626 2627 2628
      else
      {
	tab->read_first_record= join_init_read_record;
2629 2630 2631 2632 2633 2634 2635 2636
	if (i == join->const_tables)
	{
	  if (tab->select && tab->select->quick)
	  {
	    statistic_increment(select_range_count, &LOCK_status);
	  }
	  else
	  {
unknown's avatar
unknown committed
2637
	    select_lex->options|=QUERY_NO_INDEX_USED;
2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648
	    statistic_increment(select_scan_count, &LOCK_status);
	  }
	}
	else
	{
	  if (tab->select && tab->select->quick)
	  {
	    statistic_increment(select_full_range_join_count, &LOCK_status);
	  }
	  else
	  {
unknown's avatar
unknown committed
2649
	    select_lex->options|=QUERY_NO_INDEX_USED;
2650 2651 2652
	    statistic_increment(select_full_join_count, &LOCK_status);
	  }
	}
unknown's avatar
unknown committed
2653
	if (!table->no_keyread)
unknown's avatar
unknown committed
2654
	{
unknown's avatar
unknown committed
2655 2656 2657 2658 2659 2660 2661 2662 2663 2664
	  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);
2665
	    tab->read_first_record= join_read_first;
unknown's avatar
unknown committed
2666 2667
	    tab->type=JT_NEXT;		// Read with index_first / index_next
	  }
unknown's avatar
unknown committed
2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687
	}
      }
      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;
}


static void
join_free(JOIN *join)
{
  JOIN_TAB *tab,*end;
unknown's avatar
unknown committed
2688
  DBUG_ENTER("join_free");
unknown's avatar
unknown committed
2689 2690 2691

  if (join->table)
  {
2692 2693 2694 2695 2696
    /*
      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
unknown's avatar
unknown committed
2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709
      free_io_cache(join->table[join->const_tables]);
    for (tab=join->join_tab,end=tab+join->tables ; tab != end ; tab++)
    {
      delete tab->select;
      delete tab->quick;
      x_free(tab->cache.buff);
      if (tab->table)
      {
	if (tab->table->key_read)
	{
	  tab->table->key_read=0;
	  tab->table->file->extra(HA_EXTRA_NO_KEYREAD);
	}
unknown's avatar
unknown committed
2710 2711 2712
	/* Don't free index if we are using read_record */
	if (!tab->read_record.table)
	  tab->table->file->index_end();
unknown's avatar
unknown committed
2713
      }
unknown's avatar
unknown committed
2714
      end_read_record(&tab->read_record);
unknown's avatar
unknown committed
2715 2716 2717 2718 2719
    }
    join->table=0;
  }
  // We are not using tables anymore
  // Unlock all tables. We may be in an INSERT .... SELECT statement.
unknown's avatar
unknown committed
2720 2721
  if (join->lock && join->thd->lock &&
      !(join->select_options & SELECT_NO_UNLOCK))
unknown's avatar
unknown committed
2722 2723 2724 2725 2726 2727
  {
    mysql_unlock_read_tables(join->thd, join->lock);// Don't free join->lock
    join->lock=0;
  }
  join->group_fields.delete_elements();
  join->tmp_table_param.copy_funcs.delete_elements();
2728 2729
  if (join->tmp_table_param.copy_field)		// Because of bug in ecc
    delete [] join->tmp_table_param.copy_field;
unknown's avatar
unknown committed
2730
  join->tmp_table_param.copy_field=0;
unknown's avatar
unknown committed
2731
  DBUG_VOID_RETURN;
unknown's avatar
unknown committed
2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
}


/*****************************************************************************
** 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
*****************************************************************************/

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)
      {
2773
	if ((*ref_item)->eq(order->item[0],0))
unknown's avatar
unknown committed
2774 2775 2776 2777 2778
	  break;
      }
      if (order)
      {
	found++;
unknown's avatar
unknown committed
2779
	DBUG_ASSERT(!(order->used & map));
unknown's avatar
unknown committed
2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830
	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 */
  for ( ; found && start_order ; start_order=start_order->next)
  {
    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)
    return 0;					// skip this optimize /* purecov: inspected */
  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;

  for ( ; join_tab != end ; join_tab++)
  {
    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();
    ref->depend_map=depend_map;
2831
    for (JOIN_TAB **tab=join->map2table;
unknown's avatar
unknown committed
2832
	 depend_map ;
2833
	 tab++,depend_map>>=1 )
unknown's avatar
unknown committed
2834 2835
    {
      if (depend_map & 1)
2836
	ref->depend_map|=(*tab)->ref.depend_map;
unknown's avatar
unknown committed
2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852
    }
  }
}


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

static void update_depend_map(JOIN *join, ORDER *order)
{
  for ( ; order ; order=order->next)
  {
    table_map depend_map;
    order->item[0]->update_used_tables();
    order->depend_map=depend_map=order->item[0]->used_tables();
    if (!(order->depend_map & RAND_TABLE_BIT))	// Not item_sum() or RAND()
    {
2853
      for (JOIN_TAB **tab=join->map2table;
unknown's avatar
unknown committed
2854
	   depend_map ;
2855
	   tab++, depend_map>>=1)
unknown's avatar
unknown committed
2856 2857
      {
	if (depend_map & 1)
2858
	  order->depend_map|=(*tab)->ref.depend_map;
unknown's avatar
unknown committed
2859 2860 2861 2862 2863 2864 2865
      }
    }
  }
}


/*
unknown's avatar
unknown committed
2866 2867
  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
unknown's avatar
unknown committed
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
*/

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()));
unknown's avatar
unknown committed
2894
      continue;					// skip const item
unknown's avatar
unknown committed
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936
    }
    else
    {
      if (order_tables & RAND_TABLE_BIT)
	*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);
}

static int
return_zero_rows(select_result *result,TABLE_LIST *tables,List<Item> &fields,
		 bool send_row, uint select_options,const char *info,
		 Item *having, Procedure *procedure)
{
  DBUG_ENTER("return_zero_rows");

  if (select_options & SELECT_DESCRIBE)
unknown's avatar
unknown committed
2937
  {	
2938
    describe_info(current_thd, info);
unknown's avatar
unknown committed
2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
    DBUG_RETURN(0);
  }
  if (procedure)
  {
    if (result->prepare(fields))		// This hasn't been done yet
      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
2950
    if (having && having->val_int() == 0)
unknown's avatar
unknown committed
2951 2952
      send_row=0;
  }
2953
  if (!(result->send_fields(fields,1)))
unknown's avatar
unknown committed
2954 2955 2956
  {
    if (send_row)
      result->send_data(fields);
2957
    if (tables)				// Not from do_select()
2958 2959 2960 2961 2962
    {
      /* Close open cursors */
      for (TABLE_LIST *table=tables; table ; table=table->next)
	table->table->file->index_end();
    }
2963
    result->send_eof();				// Should be safe
unknown's avatar
unknown committed
2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985
  }
  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
}

/*****************************************************************************
** 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)
*****************************************************************************/

class COND_CMP :public ilink {
public:
unknown's avatar
unknown committed
2986
  static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
unknown's avatar
unknown committed
2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029
  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

/*
** change field = field to field = const for each found field = const in the
** and_level
*/

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();

3030
  if (right_item->eq(field,0) && left_item != value)
unknown's avatar
unknown committed
3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048
  {
    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);
      }
      func->set_cmp_func(item_cmp_type(func->arguments()[0]->result_type(),
				       func->arguments()[1]->result_type()));
    }
  }
3049
  else if (left_item->eq(field,0) && right_item != value)
unknown's avatar
unknown committed
3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080
  {
    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);
      }
      func->set_cmp_func(item_cmp_type(func->arguments()[0]->result_type(),
				       func->arguments()[1]->result_type()));
    }
  }
}


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;
unknown's avatar
unknown committed
3081
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
unknown's avatar
unknown committed
3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108
    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();
3109 3110 3111
      if (!(left_const && right_const) &&
	  (func->arguments()[0]->result_type() ==
	   (func->arguments()[1]->result_type())))
unknown's avatar
unknown committed
3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
      {
	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);
  /*
  ** Remove all instances of item == item
  ** Remove all and-levels where CONST item != CONST item
  */
  DBUG_EXECUTE("where",print_where(conds,"after const change"););
  conds=remove_eq_conds(conds,cond_value) ;
  DBUG_EXECUTE("info",print_where(conds,"after remove"););
  return conds;
}


/*
** 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 )
*/

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;

    *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));
      }
      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 */
      }
    }
    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)
  {
    /*
3235 3236 3237 3238 3239 3240 3241
      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
unknown's avatar
unknown committed
3242 3243 3244 3245
    */

    Item_func_isnull *func=(Item_func_isnull*) cond;
    Item **args= func->arguments();
3246
    THD *thd=current_thd;
unknown's avatar
unknown committed
3247 3248 3249 3250
    if (args[0]->type() == Item::FIELD_ITEM)
    {
      Field *field=((Item_field*) args[0])->field;
      if (field->flags & AUTO_INCREMENT_FLAG && !field->table->maybe_null &&
3251 3252
	  (thd->options & OPTION_AUTO_IS_NULL) &&
	  thd->insert_id())
unknown's avatar
unknown committed
3253
      {
unknown's avatar
unknown committed
3254
	query_cache_abort(&thd->net);
unknown's avatar
unknown committed
3255 3256 3257
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],
					new Item_int("last_insert_id()",
3258
						     thd->insert_id(),
unknown's avatar
unknown committed
3259 3260 3261
						     21))))
	{
	  cond=new_cond;
3262
	  cond->fix_fields(thd,0);
unknown's avatar
unknown committed
3263
	}
3264
	thd->insert_id(0);		// Clear for next request
unknown's avatar
unknown committed
3265 3266 3267 3268
      }
      /* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
      else if (((field->type() == FIELD_TYPE_DATE) ||
		(field->type() == FIELD_TYPE_DATETIME)) &&
3269 3270
		(field->flags & NOT_NULL_FLAG) &&
	       !field->table->maybe_null)
unknown's avatar
unknown committed
3271 3272 3273 3274 3275
      {
	COND *new_cond;
	if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
	{
	  cond=new_cond;
3276
	  cond->fix_fields(thd,0);
unknown's avatar
unknown committed
3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289
	}
      }
    }
  }
  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];
3290
    if (left_item->eq(right_item,1))
unknown's avatar
unknown committed
3291 3292 3293 3294 3295 3296 3297
    {
      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;
3298
  return cond;					// Point at next and level
unknown's avatar
unknown committed
3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311
}

/*
** Return 1 if the item is a const value in all the WHERE clause
*/

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);
unknown's avatar
unknown committed
3312
    List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
unknown's avatar
unknown committed
3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334
    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];
3335
    if (left_item->eq(comp_item,1))
unknown's avatar
unknown committed
3336 3337 3338 3339
    {
      if (right_item->const_item())
      {
	if (*const_item)
3340
	  return right_item->eq(*const_item, 1);
unknown's avatar
unknown committed
3341 3342 3343 3344
	*const_item=right_item;
	return 1;
      }
    }
3345
    else if (right_item->eq(comp_item,1))
unknown's avatar
unknown committed
3346 3347 3348 3349
    {
      if (left_item->const_item())
      {
	if (*const_item)
3350
	  return left_item->eq(*const_item, 1);
unknown's avatar
unknown committed
3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366
	*const_item=left_item;
	return 1;
      }
    }
  }
  return 0;
}


/****************************************************************************
**	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
****************************************************************************/

unknown's avatar
unknown committed
3367
Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
unknown's avatar
unknown committed
3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399
			Item_result_field ***copy_func, Field **from_field,
			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),
				maybe_null, item->name,table,1);
      else
	return new Field_double(item_sum->max_length,maybe_null,
				item->name, table, item_sum->decimals);
    case Item_sum::STD_FUNC:			/* Place for sum & count */
      if (group)
	return	new Field_string(sizeof(double)*2+sizeof(longlong),
				 maybe_null, item->name,table,1);
      else
	return new Field_double(item_sum->max_length, maybe_null,
				item->name,table,item_sum->decimals);
    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,
3400
				  item->name,table,item->unsigned_flag);
unknown's avatar
unknown committed
3401 3402 3403 3404 3405 3406 3407 3408
      case STRING_RESULT:
	if (item_sum->max_length > 255)
	  return  new Field_blob(item_sum->max_length,maybe_null,
				 item->name,table,item->binary);
	return	new Field_string(item_sum->max_length,maybe_null,
				 item->name,table,item->binary);
      }
    }
unknown's avatar
unknown committed
3409
    thd->fatal_error=1;
unknown's avatar
unknown committed
3410 3411 3412 3413 3414 3415 3416
    return 0;					// Error
  }
  case Item::FIELD_ITEM:
  {
    Field *org_field=((Item_field*) item)->field,*new_field;

    *from_field=org_field;
unknown's avatar
unknown committed
3417 3418
    // The following should always be true
    if ((new_field= org_field->new_field(&thd->mem_root,table)))
unknown's avatar
unknown committed
3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438
    {
      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::PROC_ITEM:
  case Item::FUNC_ITEM:
  case Item::COND_ITEM:
  case Item::FIELD_AVG_ITEM:
  case Item::FIELD_STD_ITEM:
    /* The following can only happen with 'CREATE TABLE ... SELECT' */
  case Item::INT_ITEM:
  case Item::REAL_ITEM:
  case Item::STRING_ITEM:
  case Item::REF_ITEM:
3439
  case Item::NULL_ITEM:
unknown's avatar
unknown committed
3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451
  {
    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,
3452
				   item->name,table, item->unsigned_flag);
unknown's avatar
unknown committed
3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477
      break;
    case STRING_RESULT:
      if (item->max_length > 255)
	new_field=  new Field_blob(item->max_length,maybe_null,
				   item->name,table,item->binary);
      else
	new_field= new Field_string(item->max_length,maybe_null,
				    item->name,table,item->binary);
      break;
    }
    if (copy_func)
      *((*copy_func)++) = (Item_result_field*) item; // Save for copy_funcs
    if (modify_item)
      ((Item_result_field*) item)->result_field=new_field;
    return new_field;
  }
  default:					// Dosen't have to be stored
    return 0;
  }
}


TABLE *
create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
		 ORDER *group, bool distinct, bool save_sum_fields,
3478
		 bool allow_distinct_limit, ulong select_options)
unknown's avatar
unknown committed
3479 3480 3481
{
  TABLE *table;
  uint	i,field_count,reclength,null_count,null_pack_length,
unknown's avatar
unknown committed
3482
        hidden_null_count, hidden_null_pack_length, hidden_field_count,
unknown's avatar
unknown committed
3483 3484
	blob_count,group_null_items;
  bool	using_unique_constraint=0;
unknown's avatar
unknown committed
3485
  bool  not_all_columns= !(select_options & TMP_TABLE_ALL_COLUMNS);
unknown's avatar
unknown committed
3486 3487 3488 3489 3490 3491 3492 3493 3494
  char	*tmpname,path[FN_REFLEN];
  byte	*pos,*group_buff;
  uchar *null_flags;
  Field **reg_field,**from_field;
  Copy_field *copy=0;
  KEY *keyinfo;
  KEY_PART_INFO *key_part_info;
  Item_result_field **copy_func;
  MI_COLUMNDEF *recinfo;
3495
  uint temp_pool_slot=MY_BIT_NONE;
3496

unknown's avatar
unknown committed
3497 3498 3499 3500 3501
  DBUG_ENTER("create_tmp_table");
  DBUG_PRINT("enter",("distinct: %d  save_sum_fields: %d  allow_distinct_limit: %d  group: %d",
		      (int) distinct, (int) save_sum_fields,
		      (int) allow_distinct_limit,test(group)));

3502
  statistic_increment(created_tmp_tables, &LOCK_status);
3503

3504
  if (use_temp_pool)
unknown's avatar
unknown committed
3505
    temp_pool_slot = bitmap_set_next(&temp_pool);
3506 3507

  if (temp_pool_slot != MY_BIT_NONE) // we got a slot
3508
    sprintf(path, "%s%s_%lx_%i", mysql_tmpdir, tmp_file_prefix,
3509 3510
	    current_pid, temp_pool_slot);
  else // if we run out of slots or we are not using tempool
3511 3512 3513
    sprintf(path,"%s%s%lx_%lx_%x",mysql_tmpdir,tmp_file_prefix,current_pid,
            thd->thread_id, thd->tmp_table++);

unknown's avatar
unknown committed
3514 3515 3516 3517 3518
  if (group)
  {
    if (!param->quick_group)
      group=0;					// Can't use group key
    else for (ORDER *tmp=group ; tmp ; tmp=tmp->next)
3519
    {
unknown's avatar
unknown committed
3520
      (*tmp->item)->marker=4;			// Store null in key
3521 3522 3523
      if ((*tmp->item)->max_length >= MAX_CHAR_WIDTH)
	using_unique_constraint=1;
    }
unknown's avatar
unknown committed
3524 3525
    if (param->group_length >= MAX_BLOB_WIDTH)
      using_unique_constraint=1;
unknown's avatar
unknown committed
3526 3527
    if (group)
      distinct=0;				// Can't use distinct
unknown's avatar
unknown committed
3528 3529 3530
  }

  field_count=param->field_count+param->func_count+param->sum_func_count;
unknown's avatar
unknown committed
3531
  hidden_field_count=param->hidden_field_count;
unknown's avatar
unknown committed
3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546
  if (!my_multi_malloc(MYF(MY_WME),
		       &table,sizeof(*table),
		       &reg_field,sizeof(Field*)*(field_count+1),
		       &from_field,sizeof(Field*)*field_count,
		       &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))
  {
unknown's avatar
unknown committed
3547
    bitmap_clear_bit(&temp_pool, temp_pool_slot);
unknown's avatar
unknown committed
3548 3549 3550 3551
    DBUG_RETURN(NULL); /* purecov: inspected */
  }
  if (!(param->copy_field=copy=new Copy_field[field_count]))
  {
unknown's avatar
unknown committed
3552
    bitmap_clear_bit(&temp_pool, temp_pool_slot);
unknown's avatar
unknown committed
3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569
    my_free((gptr) table,MYF(0)); /* purecov: inspected */
    DBUG_RETURN(NULL); /* purecov: inspected */
  }
  param->funcs=copy_func;
  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;
  table->real_name=table->path=tmpname;
  table->table_name=base_name(tmpname);
  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;
unknown's avatar
unknown committed
3570
  table->tmp_table= TMP_TABLE;
unknown's avatar
unknown committed
3571
  table->db_low_byte_first=1;			// True for HEAP and MyISAM
3572 3573
  table->temp_pool_slot = temp_pool_slot;

unknown's avatar
unknown committed
3574

unknown's avatar
unknown committed
3575
  /* Calculate which type of fields we will store in the temporary table */
unknown's avatar
unknown committed
3576

unknown's avatar
unknown committed
3577 3578
  reclength=blob_count=null_count=hidden_null_count=group_null_items=0;
  param->using_indirect_summary_function=0;
unknown's avatar
unknown committed
3579

unknown's avatar
unknown committed
3580
  List_iterator_fast<Item> li(fields);
unknown's avatar
unknown committed
3581 3582 3583 3584 3585
  Item *item;
  Field **tmp_from_field=from_field;
  while ((item=li++))
  {
    Item::Type type=item->type();
unknown's avatar
unknown committed
3586
    if (not_all_columns)
unknown's avatar
unknown committed
3587
    {
unknown's avatar
unknown committed
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599
      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;
      }
      if (item->const_item())			// We don't have to store this
	continue;
unknown's avatar
unknown committed
3600
    }
unknown's avatar
unknown committed
3601 3602 3603 3604 3605 3606 3607 3608 3609
    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=
unknown's avatar
unknown committed
3610 3611
	    create_tmp_field(thd, table,arg,arg->type(),&copy_func,
			     tmp_from_field, group != 0,not_all_columns);
unknown's avatar
unknown committed
3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626
	  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)
	    blob_count++;
	  ((Item_sum*) item)->args[i]= new Item_field(new_field);
	}
      }
    }
    else
    {
unknown's avatar
unknown committed
3627
      Field *new_field=create_tmp_field(thd, table, item,type, &copy_func,
unknown's avatar
unknown committed
3628 3629
					tmp_from_field, group != 0,
					not_all_columns);
unknown's avatar
unknown committed
3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650
      if (!new_field)
      {
	if (thd->fatal_error)
	  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)
	blob_count++;
      if (item->marker == 4 && item->maybe_null)
      {
	group_null_items++;
	new_field->flags|= GROUP_FLAG;
      }
      *(reg_field++) =new_field;
    }
unknown's avatar
unknown committed
3651 3652
    if (!--hidden_field_count)
      hidden_null_count=null_count;
unknown's avatar
unknown committed
3653
  }
unknown's avatar
unknown committed
3654
  field_count= (uint) (reg_field - table->field);
unknown's avatar
unknown committed
3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676

  /* If result table is small; use a heap */
  if (blob_count || using_unique_constraint ||
      (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)
unknown's avatar
unknown committed
3677 3678
  {
    /* We need to ensure that first byte is not 0 for the delete link */
3679
    if (param->hidden_field_count)
unknown's avatar
unknown committed
3680 3681 3682 3683 3684 3685 3686
      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;
unknown's avatar
unknown committed
3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713
  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;
    if (!(table->record[0]= (byte *) my_malloc(alloc_length*3, MYF(MY_WME))))
      goto err;
    table->record[1]= table->record[0]+alloc_length;
    table->record[2]= table->record[1]+alloc_length;
  }
  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;
unknown's avatar
unknown committed
3714
  hidden_field_count=param->hidden_field_count;
unknown's avatar
unknown committed
3715 3716 3717 3718 3719 3720 3721 3722 3723 3724
  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)
      {
3725 3726 3727 3728
	/*
	  We have to reserve one byte here for NULL bits,
	  as this is updated by 'end_update()'
	*/
unknown's avatar
unknown committed
3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762
	*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)
unknown's avatar
unknown committed
3763
      recinfo->type=FIELD_SKIP_ENDSPACE;
unknown's avatar
unknown committed
3764 3765
    else
      recinfo->type=FIELD_NORMAL;
unknown's avatar
unknown committed
3766 3767
    if (!--hidden_field_count)
      null_count=(null_count+7) & ~7;		// move to next byte
unknown's avatar
unknown committed
3768 3769
  }

unknown's avatar
unknown committed
3770
  param->copy_field_end=copy;
unknown's avatar
unknown committed
3771 3772 3773
  param->recinfo=recinfo;
  store_record(table,2);			// Make empty default record

3774 3775 3776 3777 3778 3779
  if (tmp_table_size == ~(ulong) 0)		// No limit
    table->max_rows= ~(ha_rows) 0;
  else
    table->max_rows=(((table->db_type == DB_TYPE_HEAP) ?
		      min(tmp_table_size, max_heap_table_size) :
		      tmp_table_size)/ table->reclength);
unknown's avatar
unknown committed
3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799
  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;
    for (; group ; group=group->next,key_part_info++)
    {
      Field *field=(*group->item)->tmp_table_field();
      bool maybe_null=(*group->item)->maybe_null;
3800
      key_part_info->null_bit=0;
unknown's avatar
unknown committed
3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811
      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;
unknown's avatar
unknown committed
3812
	if (!(group->field=field->new_field(&thd->mem_root,table)))
unknown's avatar
unknown committed
3813 3814 3815 3816
	  goto err; /* purecov: inspected */
	if (maybe_null)
	{
	  /*
3817 3818 3819 3820
	    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()'
unknown's avatar
unknown committed
3821
	  */
3822 3823 3824 3825 3826
	  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);
3827
	  ++group_buff;
unknown's avatar
unknown committed
3828 3829 3830 3831 3832 3833 3834 3835 3836
	}
	else
	  group->field->move_field((char*) group_buff);
	group_buff+= key_part_info->length;
      }
      keyinfo->key_length+=  key_part_info->length;
    }
  }

unknown's avatar
unknown committed
3837
  if (distinct)
unknown's avatar
unknown committed
3838
  {
unknown's avatar
unknown committed
3839 3840 3841 3842 3843 3844 3845
    /*
      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.
    */
    null_pack_length-=hidden_null_pack_length;
unknown's avatar
unknown committed
3846
    keyinfo->key_parts= ((field_count-param->hidden_field_count)+
3847
			 test(null_pack_length));
unknown's avatar
unknown committed
3848
    if (allow_distinct_limit)
unknown's avatar
unknown committed
3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869
    {
      set_if_smaller(table->max_rows,thd->select_limit);
      param->end_write_records=thd->select_limit;
    }
    else
      param->end_write_records= HA_POS_ERROR;
    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;
    keyinfo->flags=HA_NOSAME;
    keyinfo->key_length=(uint16) reclength;
    keyinfo->name=(char*) "tmp";
unknown's avatar
unknown committed
3870
    if (null_pack_length)
unknown's avatar
unknown committed
3871
    {
3872
      key_part_info->null_bit=0;
unknown's avatar
unknown committed
3873 3874
      key_part_info->offset=hidden_null_pack_length;
      key_part_info->length=null_pack_length;
unknown's avatar
unknown committed
3875 3876 3877 3878 3879 3880 3881 3882 3883 3884
      key_part_info->field=new Field_string((char*) table->record[0],
					    (uint32) key_part_info->length,
					    (uchar*) 0,
					    (uint) 0,
					    Field::NONE,
					    NullS, table, (bool) 1);
      key_part_info->key_type=FIELDFLAG_BINARY;
      key_part_info->type=    HA_KEYTYPE_BINARY;
      key_part_info++;
    }
3885
    /* Create a distinct key over the columns we are going to return */
unknown's avatar
unknown committed
3886 3887
    for (i=param->hidden_field_count, reg_field=table->field + i ;
	 i < field_count;
unknown's avatar
unknown committed
3888 3889
	 i++, reg_field++, key_part_info++)
    {
3890
      key_part_info->null_bit=0;
unknown's avatar
unknown committed
3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912
      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;
    }
  }
  if (thd->fatal_error)				// If end of memory
    goto err;					 /* purecov: inspected */
  table->db_record_offset=1;
  if (table->db_type == DB_TYPE_MYISAM)
  {
    if (create_myisam_tmp_table(table,param,select_options))
      goto err;
  }
  if (!open_tmp_table(table))
    DBUG_RETURN(table);

 err:
3913
  free_tmp_table(thd,table);                    /* purecov: inspected */
unknown's avatar
unknown committed
3914
  bitmap_clear_bit(&temp_pool, temp_pool_slot);
unknown's avatar
unknown committed
3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934
  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(ha_lock(table,F_WRLCK)); */		/* Single thread table */
  (void) table->file->extra(HA_EXTRA_QUICK);		/* Faster */
  return(0);
}


static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
3935
				    ulong options)
unknown's avatar
unknown committed
3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981
{
  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;
    MI_KEYSEG *seg= (MI_KEYSEG*) sql_calloc(sizeof(*seg) *
					    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;
3982 3983 3984 3985
      seg->flag=     0;
      seg->language= MY_CHARSET_CURRENT;
      seg->length=   keyinfo->key_part[i].length;
      seg->start=    keyinfo->key_part[i].offset;
unknown's avatar
unknown committed
3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005
      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;
      }
4006
      if (!(field->flags & NOT_NULL_FLAG))
unknown's avatar
unknown committed
4007 4008 4009
      {
	seg->null_bit= field->null_bit;
	seg->null_pos= (uint) (field->null_ptr - (uchar*) table->record[0]);
4010 4011 4012 4013 4014 4015 4016
	/*
	  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;
unknown's avatar
unknown committed
4017 4018 4019 4020 4021
      }
    }
  }
  MI_CREATE_INFO create_info;
  bzero((char*) &create_info,sizeof(create_info));
4022 4023
  if ((options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
      OPTION_BIG_TABLES)
unknown's avatar
unknown committed
4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036
    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;
  }
unknown's avatar
unknown committed
4037
  statistic_increment(created_tmp_disk_tables, &LOCK_status);
unknown's avatar
unknown committed
4038 4039 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
  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";
  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++)
    delete *ptr;
  my_free((gptr) entry->record[0],MYF(0));
  free_io_cache(entry);
4066

unknown's avatar
unknown committed
4067
  bitmap_clear_bit(&temp_pool, entry->temp_pool_slot);
4068

unknown's avatar
unknown committed
4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101
  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
*/

bool create_myisam_from_heap(TABLE *table, TMP_TABLE_PARAM *param, int error,
			     bool ignore_last_dupp_key_error)
{
  TABLE new_table;
  const char *save_proc_info;
  THD *thd=current_thd;
  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,
4102
			      thd->lex.select_lex.options | thd->options))
unknown's avatar
unknown committed
4103 4104 4105 4106 4107
    goto err2;
  if (open_tmp_table(&new_table))
    goto err1;
  table->file->index_end();
  table->file->rnd_init();
4108 4109
  if (table->no_rows)
  {
4110 4111
    new_table.file->extra(HA_EXTRA_NO_ROWS);
    new_table.no_rows=1;
4112 4113
  }

unknown's avatar
unknown committed
4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135
  /* 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);
4136 4137
  thd->proc_info= (!strcmp(save_proc_info,"Copying to tmp table") ?
		   "Copying to tmp table on disk" : save_proc_info);
unknown's avatar
unknown committed
4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153
  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);
}


4154 4155 4156 4157 4158 4159
/****************************************************************************
  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
****************************************************************************/
unknown's avatar
unknown committed
4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189

static int
do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
{
  int error;
  JOIN_TAB *join_tab;
  int (*end_select)(JOIN *, struct st_join_table *,bool);
  DBUG_ENTER("do_select");

  join->procedure=procedure;
  /*
  ** Tell the client how many fields there are in a row
  */
  if (!table)
    join->result->send_fields(*fields,1);
  else
  {
    VOID(table->file->extra(HA_EXTRA_WRITE_CACHE));
    empty_record(table);
  }
  join->tmp_table=table;			/* Save for easy recursion */
  join->fields= fields;

  /* Set up select_end */
  if (table)
  {
    if (table->group && join->tmp_table_param.sum_func_count)
    {
      if (table->keys)
      {
4190
	DBUG_PRINT("info",("Using end_update"));
unknown's avatar
unknown committed
4191 4192 4193 4194
	end_select=end_update;
	table->file->index_init(0);
      }
      else
4195 4196
      {
	DBUG_PRINT("info",("Using end_unique_update"));
unknown's avatar
unknown committed
4197
	end_select=end_unique_update;
4198
      }
unknown's avatar
unknown committed
4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235
    }
    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)
  {
    if (!(error=(*end_select)(join,join_tab,0)) || error == -3)
      error=(*end_select)(join,join_tab,1);
  }
  else
  {
    error=sub_select(join,join_tab,0);
    if (error >= 0)
      error=sub_select(join,join_tab,1);
    if (error == -3)
      error=0;					/* select_limit used */
  }
4236 4237

  /* Return 1 if error is sent;  -1 if error should be sent */
4238
  if (error < 0)
4239 4240 4241 4242
  {
    join->result->send_error(0,NullS);		/* purecov: inspected */
    error=1;					// Error sent
  }
4243
  else
unknown's avatar
unknown committed
4244
  {
4245 4246
    error=0;
    if (!table)					// If sending data to client
4247 4248 4249
    {
      join_free(join);				// Unlock all cursors
      if (join->result->send_eof())
4250
	error= 1;				// Don't send error
4251
    }
unknown's avatar
unknown committed
4252 4253 4254 4255 4256 4257 4258 4259 4260 4261
    DBUG_PRINT("info",("%ld records output",join->send_records));
  }
  if (table)
  {
    int old_error=error,tmp;
    if ((tmp=table->file->extra(HA_EXTRA_NO_CACHE)))
    {
      my_errno=tmp;
      error= -1;
    }
unknown's avatar
unknown committed
4262
    if ((tmp=table->file->index_end()))
unknown's avatar
unknown committed
4263 4264 4265 4266
    {
      my_errno=tmp;
      error= -1;
    }
4267
    if (error == -1)
unknown's avatar
unknown committed
4268 4269
      table->file->print_error(my_errno,MYF(0));
  }
4270
  DBUG_RETURN(error);
unknown's avatar
unknown committed
4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284
}


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);
  }
4285 4286 4287 4288 4289
  if (join->thd->killed)		// If aborted by user
  {
    my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
    return -2;				 /* purecov: inspected */
  }
unknown's avatar
unknown committed
4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316
  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)))
  {
unknown's avatar
unknown committed
4317 4318 4319
    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;
unknown's avatar
unknown committed
4320 4321 4322 4323 4324 4325 4326 4327 4328
    READ_RECORD *info= &join_tab->read_record;

    do
    {
      if (join->thd->killed)			// Aborted by user
      {
	my_error(ER_SERVER_SHUTDOWN,MYF(0));	/* purecov: inspected */
	return -2;				/* purecov: inspected */
      }
4329
      join->examined_rows++;
unknown's avatar
unknown committed
4330 4331 4332 4333 4334 4335 4336
      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())
	{
4337
	  if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
unknown's avatar
unknown committed
4338
	    return error;
unknown's avatar
unknown committed
4339 4340
	  if (not_used_in_distinct && found_records != join->found_records)
	    return 0;
unknown's avatar
unknown committed
4341
	}
unknown's avatar
unknown committed
4342 4343
	else
	  info->file->unlock_row();
unknown's avatar
unknown committed
4344 4345 4346
      }
    } while (!(error=info->read_record(info)));
  }
4347
  if (error > 0)				// Fatal error
unknown's avatar
unknown committed
4348 4349 4350 4351 4352 4353 4354 4355
    return -1;

  if (!found && on_expr)
  {						// OUTER JOIN
    restore_record(join_tab->table,2);		// Make empty record
    mark_as_null_row(join_tab->table);		// For group by without error
    if (!select_cond || select_cond->val_int())
    {
4356
      if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
unknown's avatar
unknown committed
4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437
	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;
}


/*****************************************************************************
** The different ways to read a record
** Returns -1 if row was not found, 0 if row was found and 1 on errors
*****************************************************************************/

static int
4438
join_read_const_table(JOIN_TAB *tab, POSITION *pos)
unknown's avatar
unknown committed
4439 4440
{
  int error;
4441 4442 4443 4444 4445 4446 4447
  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)
unknown's avatar
unknown committed
4448
  {
4449 4450 4451 4452 4453 4454 4455
    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);
unknown's avatar
unknown committed
4456
    }
4457 4458 4459 4460
  }
  else
  {
    if ((error=join_read_const(tab)))
unknown's avatar
unknown committed
4461
    {
4462 4463 4464 4465 4466
      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);
unknown's avatar
unknown committed
4467 4468
    }
  }
4469 4470 4471 4472 4473 4474 4475
  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;
unknown's avatar
unknown committed
4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486
  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
  {
4487 4488
    if ((error=table->file->read_first_row(table->record[0],
					   table->primary_key)))
unknown's avatar
unknown committed
4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529
    {
      if (error != HA_ERR_END_OF_FILE)
      {
	table->file->print_error(error,MYF(0));
	return 1;
      }
      table->null_row=1;			// This is ok.
      empty_record(table);			// Make empty record
      return -1;
    }
    store_record(table,1);
  }
  else if (!table->status)			// Only happens with left join
    restore_record(table,1);			// restore old record
  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)
      {
	sql_print_error("read_const: Got error %d when reading table %s",
unknown's avatar
unknown committed
4530
			error, table->path);
unknown's avatar
unknown committed
4531 4532 4533 4534 4535 4536 4537
	table->file->print_error(error,MYF(0));
	return 1;
      }
      return -1;
    }
    store_record(table,1);
  }
unknown's avatar
unknown committed
4538 4539 4540
  else if (!(table->status & ~STATUS_NULL_ROW))	// Only happens with left join
  {
    table->status=0;
unknown's avatar
unknown committed
4541
    restore_record(table,1);			// restore old record
unknown's avatar
unknown committed
4542
  }
unknown's avatar
unknown committed
4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554
  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) ||
4555
      (table->status & (STATUS_GARBAGE | STATUS_NO_PARENT | STATUS_NULL_ROW)))
unknown's avatar
unknown committed
4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567
  {
    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)
    {
      sql_print_error("read_key: Got error %d when reading table '%s'",error,
unknown's avatar
unknown committed
4568
		      table->path);
unknown's avatar
unknown committed
4569 4570 4571 4572
      table->file->print_error(error,MYF(0));
      return 1;
    }
  }
4573
  table->null_row=0;
unknown's avatar
unknown committed
4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592
  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)
    {
      sql_print_error("read_const: Got error %d when reading table %s",error,
unknown's avatar
unknown committed
4593
		      table->path);
unknown's avatar
unknown committed
4594 4595 4596 4597 4598 4599 4600 4601
      table->file->print_error(error,MYF(0));
      return 1;
    }
    return -1; /* purecov: inspected */
  }
  return 0;
}

4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630
/*
  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)
    {
      sql_print_error("read_const: Got error %d when reading table %s",error,
		      table->path);
      table->file->print_error(error,MYF(0));
      return 1;
    }
    return -1; /* purecov: inspected */
  }
  return 0;
}

unknown's avatar
unknown committed
4631 4632 4633 4634 4635 4636 4637 4638 4639 4640

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


static int
4641
join_read_next_same(READ_RECORD *info)
unknown's avatar
unknown committed
4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653
{
  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)
    {
      sql_print_error("read_next: Got error %d when reading table %s",error,
unknown's avatar
unknown committed
4654
		      table->path);
unknown's avatar
unknown committed
4655 4656 4657 4658 4659 4660 4661 4662 4663
      table->file->print_error(error,MYF(0));
      return 1;
    }
    table->status= STATUS_GARBAGE;
    return -1;
  }
  return 0;
}

4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689
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])))
  {
    if (error != HA_ERR_END_OF_FILE)
    {
      sql_print_error("read_next: Got error %d when reading table %s",error,
		      table->path);
      table->file->print_error(error,MYF(0));
      error= 1;
    }
    else
    {
      table->status= STATUS_GARBAGE;
      error= -1;
    }
  }
  else if (key_cmp(table, tab->ref.key_buff, tab->ref.key,
		   tab->ref.key_length))
  {
    table->status=STATUS_NOT_FOUND;
4690
    error= -1;
4691 4692 4693 4694
  }
  return error;
}

unknown's avatar
unknown committed
4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718

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();
4719 4720
  init_read_record(&tab->read_record, tab->join->thd, tab->table,
		   tab->select,1,1);
unknown's avatar
unknown committed
4721 4722 4723 4724
  return (*tab->read_record.read_record)(&tab->read_record);
}

static int
4725
join_read_first(JOIN_TAB *tab)
unknown's avatar
unknown committed
4726 4727 4728
{
  int error;
  TABLE *table=tab->table;
unknown's avatar
unknown committed
4729 4730
  if (!table->key_read && (table->used_keys & ((key_map) 1 << tab->index)) &&
      !table->no_keyread)
unknown's avatar
unknown committed
4731 4732 4733 4734 4735
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
4736
  tab->read_record.read_record=join_read_next;
unknown's avatar
unknown committed
4737 4738 4739 4740 4741 4742 4743 4744 4745
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
  error=tab->table->file->index_first(tab->table->record[0]);
  if (error)
  {
    if (error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE)
    {
unknown's avatar
unknown committed
4746 4747
      sql_print_error("read_first_with_key: Got error %d when reading table",
		      error);
unknown's avatar
unknown committed
4748 4749 4750 4751 4752 4753 4754 4755
      table->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}

4756

unknown's avatar
unknown committed
4757
static int
4758
join_read_next(READ_RECORD *info)
unknown's avatar
unknown committed
4759 4760 4761 4762 4763 4764 4765
{
  int error=info->file->index_next(info->record);
  if (error)
  {
    if (error != HA_ERR_END_OF_FILE)
    {
      sql_print_error("read_next_with_key: Got error %d when reading table %s",
unknown's avatar
unknown committed
4766
		      error, info->table->path);
unknown's avatar
unknown committed
4767 4768 4769 4770 4771 4772 4773 4774 4775
      info->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}

static int
4776
join_read_last(JOIN_TAB *tab)
unknown's avatar
unknown committed
4777 4778 4779 4780 4781 4782 4783 4784 4785
{
  TABLE *table=tab->table;
  int error;
  if (!table->key_read && (table->used_keys & ((key_map) 1 << tab->index)))
  {
    table->key_read=1;
    table->file->extra(HA_EXTRA_KEYREAD);
  }
  tab->table->status=0;
4786
  tab->read_record.read_record=join_read_prev;
unknown's avatar
unknown committed
4787 4788 4789 4790 4791 4792 4793 4794 4795
  tab->read_record.table=table;
  tab->read_record.file=table->file;
  tab->read_record.index=tab->index;
  tab->read_record.record=table->record[0];
  error=tab->table->file->index_last(tab->table->record[0]);
  if (error)
  {
    if (error != HA_ERR_END_OF_FILE)
    {
unknown's avatar
unknown committed
4796
      sql_print_error("read_last_with_key: Got error %d when reading table",
unknown's avatar
unknown committed
4797
		      error, table->path);
unknown's avatar
unknown committed
4798 4799 4800 4801 4802 4803 4804 4805
      table->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}

4806

unknown's avatar
unknown committed
4807
static int
4808
join_read_prev(READ_RECORD *info)
unknown's avatar
unknown committed
4809 4810 4811 4812 4813 4814 4815
{
  int error=info->file->index_prev(info->record);
  if (error)
  {
    if (error != HA_ERR_END_OF_FILE)
    {
      sql_print_error("read_prev_with_key: Got error %d when reading table: %s",
unknown's avatar
unknown committed
4816
		      error,info->table->path);
unknown's avatar
unknown committed
4817 4818 4819 4820 4821 4822 4823 4824
      info->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}

4825

unknown's avatar
unknown committed
4826 4827 4828 4829 4830 4831
static int
join_ft_read_first(JOIN_TAB *tab)
{
  int error;
  TABLE *table= tab->table;

unknown's avatar
unknown committed
4832
#if NOT_USED_YET
unknown's avatar
unknown committed
4833
  if (cp_buffer_from_ref(&tab->ref))       // as ft-key doesn't use store_key's
unknown's avatar
unknown committed
4834
    return -1;                             // see also FT_SELECT::init()
unknown's avatar
unknown committed
4835
#endif
4836
  table->file->ft_init();
unknown's avatar
unknown committed
4837 4838 4839 4840 4841 4842

  error=table->file->ft_read(table->record[0]);
  if (error)
  {
    if (error != HA_ERR_END_OF_FILE)
    {
4843
      sql_print_error("ft_read_first: Got error %d when reading table %s",
unknown's avatar
unknown committed
4844
                      error, table->path);
unknown's avatar
unknown committed
4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861
      table->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}

static int
join_ft_read_next(READ_RECORD *info)
{
  int error=info->file->ft_read(info->table->record[0]);
  if (error)
  {
    if (error != HA_ERR_END_OF_FILE)
    {
      sql_print_error("ft_read_next: Got error %d when reading table %s",
unknown's avatar
unknown committed
4862
                      error, info->table->path);
unknown's avatar
unknown committed
4863 4864 4865 4866 4867 4868 4869 4870 4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886
      info->file->print_error(error,MYF(0));
      return 1;
    }
    return -1;
  }
  return 0;
}


/*****************************************************************************
** 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
*****************************************************************************/

	/* ARGSUSED */
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;
4887
    if (join->having && join->having->val_int() == 0)
unknown's avatar
unknown committed
4888
      DBUG_RETURN(0);				// Didn't match having
4889
    error=0;
unknown's avatar
unknown committed
4890 4891
    if (join->procedure)
      error=join->procedure->send_row(*join->fields);
4892
    else if (join->do_send_rows)
unknown's avatar
unknown committed
4893 4894 4895
      error=join->result->send_data(*join->fields);
    if (error)
      DBUG_RETURN(-1); /* purecov: inspected */
4896 4897 4898 4899
    if (++join->send_records >= join->thd->select_limit && join->do_send_rows)
    {
      if (join->select_options & OPTION_FOUND_ROWS)
      {
4900
	JOIN_TAB *jt=join->join_tab;
4901
	if ((join->tables == 1) && !join->tmp_table && !join->sort_and_group
4902
	    && !join->send_group_parts && !join->having && !jt->select_cond &&
4903
	    !(jt->select && jt->select->quick) &&
4904
	    !(jt->table->file->table_flags() & HA_NOT_EXACT_COUNT))
4905
	{
4906
	  /* Join over all rows in table;  Return number of found rows */
4907 4908
	  TABLE *table=jt->table;

4909
	  join->select_options ^= OPTION_FOUND_ROWS;
4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920
	  if (table->record_pointers ||
	      (table->io_cache && my_b_inited(table->io_cache)))
	  {
	    /* Using filesort */
	    join->send_records= table->found_records;
	  }
	  else
	  {
	    table->file->info(HA_STATUS_VARIABLE);
	    join->send_records = table->file->records;
	  }
4921 4922 4923 4924 4925 4926 4927
	}
	else 
	{
	  join->do_send_rows=0;
	  join->thd->select_limit = HA_POS_ERROR;
	  DBUG_RETURN(0);
	}
4928
      }
unknown's avatar
unknown committed
4929
      DBUG_RETURN(-3);				// Abort nicely
4930
    }
unknown's avatar
unknown committed
4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957
  }
  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)
      {
4958
	int error=0;
unknown's avatar
unknown committed
4959 4960
	if (join->procedure)
	{
4961
	  if (join->having && join->having->val_int() == 0)
unknown's avatar
unknown committed
4962
	    error= -1;				// Didn't satisfy having
4963
 	  else if (join->do_send_rows)
unknown's avatar
unknown committed
4964 4965 4966 4967 4968 4969 4970
	    error=join->procedure->send_row(*join->fields) ? 1 : 0;
	  if (end_of_records && join->procedure->end_of_records())
	    error= 1;				// Fatal error
	}
	else
	{
	  if (!join->first_record)
4971 4972
	  {
	    /* No matching rows for group function */
unknown's avatar
unknown committed
4973
	    clear_tables(join);
4974 4975
	    copy_fields(&join->tmp_table_param);
	  }
4976
	  if (join->having && join->having->val_int() == 0)
unknown's avatar
unknown committed
4977
	    error= -1;				// Didn't satisfy having
4978
	  else if (join->do_send_rows)
unknown's avatar
unknown committed
4979 4980 4981 4982
	    error=join->result->send_data(*join->fields) ? 1 : 0;
	}
	if (error > 0)
	  DBUG_RETURN(-1);			/* purecov: inspected */
4983 4984 4985 4986 4987
	if (end_of_records)
	{
	  join->send_records++;
	  DBUG_RETURN(0);
	}
4988 4989 4990 4991 4992 4993 4994 4995
	if (!error && ++join->send_records >= join->thd->select_limit &&
	    join->do_send_rows)
	{
	  if (!(join->select_options & OPTION_FOUND_ROWS))
	    DBUG_RETURN(-3);				// Abort nicely
	  join->do_send_rows=0;
	  join->thd->select_limit = HA_POS_ERROR;
        }
unknown's avatar
unknown committed
4996 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040
      }
    }
    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);
      init_sum_functions(join->sum_funcs);
      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);
    copy_funcs(join->tmp_table_param.funcs);

5041
#ifdef TO_BE_DELETED
unknown's avatar
unknown committed
5042 5043 5044 5045 5046 5047 5048 5049 5050 5051
    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();
5052
	  field->ptr[-1]= (byte) (field->is_null() ? 1 : 0);
unknown's avatar
unknown committed
5053 5054 5055
	}
      }
    }
5056
#endif
unknown's avatar
unknown committed
5057 5058
    if (!join->having || join->having->val_int())
    {
unknown's avatar
unknown committed
5059
      join->found_records++;
unknown's avatar
unknown committed
5060 5061
      if ((error=table->file->write_row(table->record[0])))
      {
unknown's avatar
unknown committed
5062 5063 5064 5065 5066 5067
	if (error == HA_ERR_FOUND_DUPP_KEY ||
	    error == HA_ERR_FOUND_DUPP_UNIQUE)
	  goto end;
	if (create_myisam_from_heap(table, &join->tmp_table_param, error,1))
	  DBUG_RETURN(1);			// Not a table_is_full error
	table->uniques=0;			// To ensure rows are the same
5068
      }
unknown's avatar
unknown committed
5069
      if (++join->send_records >= join->tmp_table_param.end_write_records &&
5070 5071 5072 5073 5074 5075 5076
	  join->do_send_rows)
      {
	if (!(join->select_options & OPTION_FOUND_ROWS))
	  DBUG_RETURN(-3);
	join->do_send_rows=0;
	join->thd->select_limit = HA_POS_ERROR;
	DBUG_RETURN(0);
unknown's avatar
unknown committed
5077 5078 5079
      }
    }
  }
unknown's avatar
unknown committed
5080
end:
unknown's avatar
unknown committed
5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103
  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 */
  }

unknown's avatar
unknown committed
5104
  join->found_records++;
unknown's avatar
unknown committed
5105 5106 5107 5108 5109 5110
  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);
5111
    /* Store in the used key if the field was 0 */
unknown's avatar
unknown committed
5112
    if (item->maybe_null)
5113
      group->buff[-1]=item->null_value ? 1 : 0;
unknown's avatar
unknown committed
5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225
  }
  // 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 */
    restore_record(table,1);
    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);
  copy_funcs(join->tmp_table_param.funcs);
  if ((error=table->file->write_row(table->record[0])))
  {
    if (create_myisam_from_heap(table, &join->tmp_table_param, error, 0))
      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.
  copy_funcs(join->tmp_table_param.funcs);

  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 */
    }
    restore_record(table,1);
    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)
5226 5227
	{
	  /* No matching rows for group function */
unknown's avatar
unknown committed
5228
	  clear_tables(join);
5229 5230
	  copy_fields(&join->tmp_table_param);
	}
unknown's avatar
unknown committed
5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271
	copy_sum_funcs(join->sum_funcs);
	if (!join->having || join->having->val_int())
	{
	  if ((error=table->file->write_row(table->record[0])))
	  {
	    if (create_myisam_from_heap(table, &join->tmp_table_param,
					error, 0))
	      DBUG_RETURN(1);			// Not a table_is_full error
	  }
	  else
	    join->send_records++;
	}
	if (end_of_records)
	  DBUG_RETURN(0);
      }
    }
    else
    {
      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);
      copy_funcs(join->tmp_table_param.funcs);
      init_sum_functions(join->sum_funcs);
      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);
}


/*****************************************************************************
** Remove calculation with tables that aren't yet read. Remove also tests
5272
** against fields that are read through key where the table is not a
unknown's avatar
unknown committed
5273
** outer join table.
unknown's avatar
unknown committed
5274 5275 5276 5277 5278 5279 5280 5281 5282
** We can't remove tests that are made against columns which are stored
** in sorted order.
*****************************************************************************/

/* 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;
5283 5284
  // No need to change const test. We also have to keep tests on LEFT JOIN
  if (!field->table->const_table && !field->table->maybe_null)
unknown's avatar
unknown committed
5285 5286
  {
    Item *ref_item=part_of_refkey(field->table,field);
5287
    if (ref_item && ref_item->eq(right_item,1))
unknown's avatar
unknown committed
5288 5289
    {
      if (right_item->type() == Item::FIELD_ITEM)
5290 5291
	return (field->eq_def(((Item_field *) right_item)->field));
      if (right_item->const_item() && !(right_item->is_null()))
unknown's avatar
unknown committed
5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 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 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 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
      {
	// We can remove binary fields and numerical fields except float,
	// as float comparison isn't 100 % secure
	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)
    {
      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;
      return new_cond;
    }
  }

  /*
  ** 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
  */

  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)
{
  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;
}


/*****************************************************************************
** 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
unknown's avatar
unknown committed
5412
**          used_key_parts is set to key parts used if length != 0
unknown's avatar
unknown committed
5413 5414
*****************************************************************************/

unknown's avatar
unknown committed
5415 5416
static int test_if_order_by_key(ORDER *order, TABLE *table, uint idx,
				uint *used_key_parts)
unknown's avatar
unknown committed
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
{
  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++;
  }
unknown's avatar
unknown committed
5448
  *used_key_parts= (uint) (key_part - table->key_info[idx].key_part);
unknown's avatar
unknown committed
5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470
  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;
}


5471 5472 5473 5474 5475 5476 5477 5478 5479 5480
/*
  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.
*/
unknown's avatar
unknown committed
5481 5482

static bool
5483 5484
test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
			bool no_changes)
unknown's avatar
unknown committed
5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500
{
  int ref_key;
  TABLE *table=tab->table;
  SQL_SELECT *select=tab->select;
  key_map usable_keys;
  DBUG_ENTER("test_if_skip_sort_order");

  /* 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;
    }
5501
    usable_keys&=((Item_field*) (*tmp_order->item))->field->part_of_sortkey;
unknown's avatar
unknown committed
5502 5503 5504 5505 5506 5507 5508 5509 5510 5511
  }

  ref_key= -1;
  if (tab->ref.key >= 0)			// Constant range in WHERE
    ref_key=tab->ref.key;
  else if (select && select->quick)		// Range found by opt_range
    ref_key=select->quick->index;

  if (ref_key >= 0)
  {
5512 5513 5514
    /*
      We come here when there is a REF key.
    */
5515
    int order_direction;
unknown's avatar
unknown committed
5516
    uint used_key_parts;
unknown's avatar
unknown committed
5517 5518
    /* Check if we get the rows in requested sorted order by using the key */
    if ((usable_keys & ((key_map) 1 << ref_key)) &&
unknown's avatar
unknown committed
5519 5520
	(order_direction = test_if_order_by_key(order,table,ref_key,
						&used_key_parts)))
5521
    {
5522
      if (order_direction == -1)		// If ORDER BY ... DESC
5523
      {
unknown's avatar
unknown committed
5524 5525
	if (select && select->quick)
	{
5526 5527 5528 5529 5530
	  /*
	    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())
unknown's avatar
unknown committed
5531
	  {
5532 5533 5534 5535 5536 5537 5538 5539 5540
	    // 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;
unknown's avatar
unknown committed
5541 5542 5543 5544 5545 5546 5547
	  }
	  DBUG_RETURN(1);
	}
	if (tab->ref.key_parts < used_key_parts)
	{
	  /*
	    SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
5548 5549 5550

	    Use a traversal function that starts by reading the last row
	    with key part (A) and then traverse the index backwards.
unknown's avatar
unknown committed
5551
	  */
5552
	  if (table->file->table_flags() & HA_NOT_READ_PREFIX_LAST)
5553 5554 5555 5556
	    DBUG_RETURN(1);
	  tab->read_first_record=       join_read_last_key;
	  tab->read_record.read_record= join_read_prev_same;
	  /* fall through */
unknown's avatar
unknown committed
5557
	}
5558
      }
unknown's avatar
unknown committed
5559
      DBUG_RETURN(1);			/* No need to sort */
5560
    }
unknown's avatar
unknown committed
5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574
  }
  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)
unknown's avatar
unknown committed
5575
      keys&= (table->used_keys | table->file->keys_to_use_for_scanning());
unknown's avatar
unknown committed
5576 5577 5578

    for (nr=0; keys ; keys>>=1, nr++)
    {
unknown's avatar
unknown committed
5579
      uint not_used;
unknown's avatar
unknown committed
5580 5581 5582
      if (keys & 1)
      {
	int flag;
unknown's avatar
unknown committed
5583
	if ((flag=test_if_order_by_key(order, table, nr, &not_used)))
unknown's avatar
unknown committed
5584
	{
5585 5586 5587
	  if (!no_changes)
	  {
	    tab->index=nr;
5588 5589
	    tab->read_first_record=  (flag > 0 ? join_read_first:
				      join_read_last);
5590 5591
	    table->file->index_init(nr);
	    tab->type=JT_NEXT;	// Read with index_first(), index_next()
unknown's avatar
unknown committed
5592 5593 5594 5595 5596
	    if (table->used_keys & ((key_map) 1 << nr))
	    {
	      table->key_read=1;
	      table->file->extra(HA_EXTRA_KEYREAD);
	    }
5597
	  }
unknown's avatar
unknown committed
5598 5599 5600 5601 5602 5603 5604 5605
	  DBUG_RETURN(1);
	}
      }
    }
  }
  DBUG_RETURN(0);				// Can't use index.
}

unknown's avatar
unknown committed
5606 5607 5608 5609 5610 5611 5612 5613

/*****************************************************************************
  If not selecting by given key, create an index how records should be read
  return: 0  ok
	  -1 some fatal error
	   1  no records
*****************************************************************************/

unknown's avatar
unknown committed
5614 5615 5616 5617 5618
static int
create_sort_index(JOIN_TAB *tab,ORDER *order,ha_rows select_limit)
{
  SORT_FIELD *sortorder;
  uint length;
5619
  ha_rows examined_rows;
unknown's avatar
unknown committed
5620 5621 5622 5623
  TABLE *table=tab->table;
  SQL_SELECT *select=tab->select;
  DBUG_ENTER("create_sort_index");

5624
  if (test_if_skip_sort_order(tab,order,select_limit,0))
unknown's avatar
unknown committed
5625 5626 5627 5628 5629
    DBUG_RETURN(0);
  if (!(sortorder=make_unireg_sortorder(order,&length)))
    goto err;				/* purecov: inspected */
  /* It's not fatal if the following alloc fails */
  table->io_cache=(IO_CACHE*) my_malloc(sizeof(IO_CACHE),
5630
					MYF(MY_WME | MY_ZEROFILL));
unknown's avatar
unknown committed
5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652
  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.
      */
unknown's avatar
unknown committed
5653
      if (!(select->quick=get_ft_or_quick_select_for_ref(table, tab)))
unknown's avatar
unknown committed
5654 5655 5656
	goto err;
    }
  }
5657 5658 5659
  if (table->tmp_table)
    table->file->info(HA_STATUS_VARIABLE);	// Get record count
  table->found_records=filesort(table,sortorder,length,
5660
				select, 0L, select_limit, &examined_rows);
5661
  tab->records=table->found_records;		// For SQL_CALC_ROWS
unknown's avatar
unknown committed
5662 5663 5664 5665 5666
  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;
5667
  tab->join->examined_rows+=examined_rows;
unknown's avatar
unknown committed
5668 5669 5670 5671 5672 5673 5674 5675 5676 5677
  if (table->key_read)				// Restore if we used indexes
  {
    table->key_read=0;
    table->file->extra(HA_EXTRA_NO_KEYREAD);
  }
  DBUG_RETURN(table->found_records == HA_POS_ERROR);
err:
  DBUG_RETURN(-1);
}

5678 5679 5680 5681
/*
** Add the HAVING criteria to table->select
*/

unknown's avatar
unknown committed
5682
#ifdef NOT_YET
5683 5684 5685 5686 5687 5688
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;

unknown's avatar
unknown committed
5689
  DBUG_EXECUTE("where",print_where(*having,"having"););
5690 5691 5692 5693 5694 5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709
  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;
    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;
}
unknown's avatar
unknown committed
5710
#endif
5711 5712


unknown's avatar
unknown 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 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752
/*****************************************************************************
** Remove duplicates from tmp table
** This should be recoded to add a uniuqe index to the table and remove
** dupplicates
** Table is a locked single thread table
** fields is the number of fields to check (from the end)
*****************************************************************************/

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
5753
remove_duplicates(JOIN *join, TABLE *entry,List<Item> &fields, Item *having)
unknown's avatar
unknown committed
5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766
{
  int error;
  ulong reclength,offset;
  uint field_count;
  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++))
unknown's avatar
unknown committed
5767 5768
  {
    if (item->tmp_table_field() && ! item->const_item())
unknown's avatar
unknown committed
5769
      field_count++;
unknown's avatar
unknown committed
5770
  }
unknown's avatar
unknown committed
5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788

  if (!field_count)
  {						// only const items
    join->thd->select_limit=1;			// Only send first row
    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 <
	sortbuff_size)))
    error=remove_dup_with_hash_index(join->thd, entry,
				     field_count, first_field,
5789
				     reclength, having);
unknown's avatar
unknown committed
5790
  else
5791 5792
    error=remove_dup_with_compare(join->thd, entry, first_field, offset,
				  having);
unknown's avatar
unknown committed
5793 5794 5795 5796 5797 5798 5799

  free_blobs(first_field);
  DBUG_RETURN(error);
}


static int remove_dup_with_compare(THD *thd, TABLE *table, Field **first_field,
5800
				   ulong offset, Item *having)
unknown's avatar
unknown committed
5801 5802 5803
{
  handler *file=table->file;
  char *org_record,*new_record;
unknown's avatar
unknown committed
5804
  byte *record;
unknown's avatar
unknown committed
5805 5806 5807 5808
  int error;
  ulong reclength=table->reclength-offset;
  DBUG_ENTER("remove_dup_with_compare");

5809
  org_record=(char*) (record=table->record[0])+offset;
unknown's avatar
unknown committed
5810 5811 5812
  new_record=(char*) table->record[1]+offset;

  file->rnd_init();
5813
  error=file->rnd_next(record);
unknown's avatar
unknown committed
5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829
  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;
    }
5830 5831 5832 5833
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
5834
      error=file->rnd_next(record);
5835 5836
      continue;
    }
unknown's avatar
unknown committed
5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848
    if (copy_blobs(first_field))
    {
      my_error(ER_OUT_OF_SORTMEMORY,MYF(0));
      error=0;
      goto err;
    }
    memcpy(new_record,org_record,reclength);

    /* Read through rest of file and mark duplicated rows deleted */
    bool found=0;
    for (;;)
    {
5849
      if ((error=file->rnd_next(record)))
unknown's avatar
unknown committed
5850 5851 5852 5853 5854 5855 5856 5857 5858
      {
	if (error == HA_ERR_RECORD_DELETED)
	  continue;
	if (error == HA_ERR_END_OF_FILE)
	  break;
	goto err;
      }
      if (compare_record(table, first_field) == 0)
      {
5859
	if ((error=file->delete_row(record)))
unknown's avatar
unknown committed
5860 5861 5862 5863 5864
	  goto err;
      }
      else if (!found)
      {
	found=1;
5865
	file->position(record);	// Remember position
unknown's avatar
unknown committed
5866 5867 5868 5869 5870
      }
    }
    if (!found)
      break;					// End of file
    /* Restart search on next row */
5871
    error=file->restart_rnd_next(record,file->ref);
unknown's avatar
unknown committed
5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891
  }

  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,
5892 5893
				      ulong key_length,
				      Item *having)
unknown's avatar
unknown committed
5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926 5927 5928 5929 5930 5931 5932 5933 5934 5935 5936 5937 5938 5939 5940
{
  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);
  if (hash_init(&hash, (uint) file->records, 0, key_length,
		(hash_get_key) 0, 0, 0))
  {
    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;
    }
5941 5942 5943 5944 5945
    if (having && !having->val_int())
    {
      if ((error=file->delete_row(record)))
	goto err;
      continue;
5946
    }
unknown's avatar
unknown committed
5947 5948 5949 5950 5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961

    /* 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;
    }
5962 5963
    else
      (void) hash_insert(&hash, key_pos-key_length);
unknown's avatar
unknown committed
5964 5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977 5978 5979 5980 5981 5982
    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);
}


unknown's avatar
unknown committed
5983
SORT_FIELD *make_unireg_sortorder(ORDER *order, uint *length)
unknown's avatar
unknown committed
5984 5985 5986 5987 5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017
{
  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);
}


/*****************************************************************************
6018 6019 6020 6021
  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
unknown's avatar
unknown committed
6022 6023 6024 6025 6026 6027 6028 6029 6030
******************************************************************************/

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;
6031
  JOIN_TAB *join_tab;
unknown's avatar
unknown committed
6032 6033 6034 6035 6036
  DBUG_ENTER("join_init_cache");

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

6037 6038
  join_tab=tables;
  for (i=0 ; i < table_count ; i++,join_tab++)
unknown's avatar
unknown committed
6039
  {
6040 6041 6042 6043
    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;
unknown's avatar
unknown committed
6044 6045 6046 6047 6048 6049 6050 6051 6052 6053 6054 6055 6056 6057 6058 6059 6060 6061 6062 6063 6064 6065 6066 6067 6068 6069 6070 6071 6072 6073 6074 6075 6076 6077 6078 6079 6080 6081 6082
  }
  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;
6083
      copy->length=tables[i].table->null_bytes;
unknown's avatar
unknown committed
6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095 6096 6097 6098 6099 6100 6101 6102 6103 6104 6105 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116 6117 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140 6141 6142 6143 6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162 6163 6164 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 6194 6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 6205 6206 6207 6208 6209 6210 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 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293 6294 6295 6296 6297 6298 6299 6300 6301 6302 6303 6304 6305 6306 6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328
      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 */
  size=max(join_buff_size,cache->length);
  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;

  /*
  ** There is room in cache. Put record there
  */
  cache->records++;
  for (copy=cache->field ; copy < end_field; copy++)
  {
    if (copy->blob_field)
    {
      if (last_record)
      {
	copy->blob_field->get_image((char*) pos,copy->length+sizeof(char*));
	pos+=copy->length+sizeof(char*);
      }
      else
      {
	copy->blob_field->get_image((char*) pos,copy->length); // blob length
	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)
      {
	copy->blob_field->set_image((char*) pos,copy->length+sizeof(char*));
	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;
}


/*****************************************************************************
** Group and order functions
*****************************************************************************/

/*
** 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.
*/

static int
find_order_in_list(THD *thd,TABLE_LIST *tables,ORDER *order,List<Item> &fields,
		   List<Item> &all_fields)
{
  if ((*order->item)->type() == Item::INT_ITEM)
  {						/* Order by position */
    Item *item=0;
    List_iterator<Item> li(fields);

    for (uint count= (uint) ((Item_int*) (*order->item))->value ;
	 count-- && (item=li++) ;) ;
    if (!item)
    {
      my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),
		      MYF(0),(*order->item)->full_name(),
	       thd->where);
      return 1;
    }
    order->item=li.ref();
    order->in_field_list=1;
    return 0;
  }
  const char *save_where=thd->where;
  thd->where=0;					// No error if not found
  Item **item=find_item_in_list(*order->item,fields);
  thd->where=save_where;
  if (item)
  {
    order->item=item;				// use it
    order->in_field_list=1;
    return 0;
  }
  order->in_field_list=0;
  if ((*order->item)->fix_fields(thd,tables) || thd->fatal_error)
    return 1;					// Wrong field
  all_fields.push_front(*order->item);		// Add new field to field list
  order->item=(Item**) all_fields.head_ref();
  return 0;
}


/*
** 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.
*/

unknown's avatar
unknown committed
6329
int setup_order(THD *thd,TABLE_LIST *tables,List<Item> &fields,
unknown's avatar
unknown committed
6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343 6344 6345 6346 6347 6348 6349
	     List<Item> &all_fields, ORDER *order)
{
  thd->where="order clause";
  for (; order; order=order->next)
  {
    if (find_order_in_list(thd,tables,order,fields,all_fields))
      return 1;
  }
  return 0;
}


static int
setup_group(THD *thd,TABLE_LIST *tables,List<Item> &fields,
	    List<Item> &all_fields, ORDER *order, bool *hidden_group_fields)
{
  *hidden_group_fields=0;
  if (!order)
    return 0;				/* Everything is ok */

6350
  if (thd->sql_mode & MODE_ONLY_FULL_GROUP_BY)
unknown's avatar
unknown committed
6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371
  {
    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";
  for ( ; order; order=order->next)
  {
    if (find_order_in_list(thd,tables,order,fields,all_fields))
      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;
    }
  }
6372
  if (thd->sql_mode & MODE_ONLY_FULL_GROUP_BY)
unknown's avatar
unknown committed
6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 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 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440 6441 6442 6443 6444 6445 6446 6447 6448 6449 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
  {
    /* Don't allow one to use fields that is not used in GROUP BY */
    Item *item;
    List_iterator<Item> li(fields);

    while ((item=li++))
    {
      if (item->type() != Item::SUM_FUNC_ITEM && !item->marker)
      {
	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;
}

/*
** Add fields with aren't used at start of field list. Return FALSE if ok
*/

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...
  thd->where=0;					// Don't give error
  for ( ; new_field ; new_field=new_field->next)
  {
    if ((item=find_item_in_list(*new_field->item,fields)))
      new_field->item=item;			/* Change to shared Item */
    else
    {
      thd->where="procedure list";
      if ((*new_field->item)->fix_fields(thd,tables))
	DBUG_RETURN(1); /* purecov: inspected */
      thd->where=0;
      all_fields.push_front(*new_field->item);
      new_field->item=all_fields.head_ref();
    }
  }
  DBUG_RETURN(0);
}

/*
** 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'.
*/

static ORDER *
create_distinct_group(ORDER *order_list,List<Item> &fields)
{
  List_iterator<Item> li(fields);
  Item *item;
  ORDER *order,*group,**prev;

  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)
    {
      ORDER *ord=(ORDER*) sql_memdup(order,sizeof(ORDER));
      if (!ord)
	return 0;
      *prev=ord;
      prev= &ord->next;
      (*ord->item)->marker=1;
    }
  }

  li.rewind();
  while ((item=li++))
  {
    if (item->const_item() || item->with_sum_func)
      continue;
    if (!item->marker)
    {
      ORDER *ord=(ORDER*) sql_calloc(sizeof(ORDER));
      if (!ord)
	return 0;
      ord->item=li.ref();
      ord->asc=1;
      *prev=ord;
      prev= &ord->next;
    }
  }
  *prev=0;
  return group;
}


/*****************************************************************************
** Update join with count of the different type of fields
*****************************************************************************/

void
unknown's avatar
unknown committed
6480 6481
count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
		  bool reset_with_sum_func)
unknown's avatar
unknown committed
6482 6483 6484 6485
{
  List_iterator<Item> li(fields);
  Item *field;

6486
  param->field_count=param->sum_func_count=param->func_count=
unknown's avatar
unknown committed
6487
    param->hidden_field_count=0;
unknown's avatar
unknown committed
6488 6489 6490 6491 6492 6493 6494 6495 6496 6497 6498 6499 6500 6501 6502 6503 6504 6505 6506 6507 6508 6509 6510 6511 6512
  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
unknown's avatar
unknown committed
6513
    {
unknown's avatar
unknown committed
6514
      param->func_count++;
unknown's avatar
unknown committed
6515 6516 6517
      if (reset_with_sum_func)
	field->with_sum_func=0;
    }
unknown's avatar
unknown committed
6518 6519 6520 6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532
  }
}


/*
  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)
  {
6533
    if ((*a->item)->eq(*b->item,1))
unknown's avatar
unknown committed
6534 6535 6536 6537 6538 6539 6540 6541 6542 6543 6544 6545 6546 6547 6548 6549 6550 6551 6552 6553 6554 6555 6556 6557 6558 6559
      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)
  {
6560
    if (!(*a->item)->eq(*b->item,1))
unknown's avatar
unknown committed
6561 6562 6563 6564 6565 6566 6567 6568 6569 6570 6571 6572 6573 6574 6575 6576 6577 6578 6579
      DBUG_RETURN(0);
    map|=a->item[0]->used_tables();
  }
  if (!map || (map & RAND_TABLE_BIT))
    DBUG_RETURN(0);

  for ( ; !(map & tables->table->map) ; tables=tables->next) ;
  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)
{
6580 6581
  uint key_length=0, parts=0, null_parts=0;

unknown's avatar
unknown committed
6582 6583 6584 6585 6586 6587 6588 6589 6590 6591 6592 6593 6594 6595 6596 6597 6598 6599 6600 6601
  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)
6602
      null_parts++;
unknown's avatar
unknown committed
6603
  }
6604
  join->tmp_table_param.group_length=key_length+null_parts;
unknown's avatar
unknown committed
6605
  join->tmp_table_param.group_parts=parts;
6606
  join->tmp_table_param.group_null_parts=null_parts;
unknown's avatar
unknown committed
6607 6608 6609 6610 6611 6612 6613 6614 6615 6616 6617 6618 6619 6620 6621 6622 6623 6624 6625 6626 6627 6628 6629 6630 6631 6632 6633 6634 6635 6636 6637 6638 6639 6640 6641 6642 6643 6644 6645 6646 6647 6648 6649 6650 6651 6652 6653 6654 6655 6656
}


/*
** Get a list of buffers for saveing last group
** Groups are saved in reverse order for easyer check loop
*/

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)
{
  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;
  }
  return idx;
}



/*
** 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
*/

bool
unknown's avatar
unknown committed
6657
setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields)
unknown's avatar
unknown committed
6658 6659 6660 6661 6662 6663 6664
{
  Item *pos;
  List_iterator<Item> li(fields);
  Copy_field *copy;
  DBUG_ENTER("setup_copy_fields");

  if (!(copy=param->copy_field= new Copy_field[param->field_count]))
6665
    goto err2;
unknown's avatar
unknown committed
6666 6667 6668 6669 6670 6671 6672 6673 6674 6675 6676 6677 6678 6679 6680 6681 6682 6683 6684

  param->copy_funcs.empty();
  while ((pos=li++))
  {
    if (pos->type() == Item::FIELD_ITEM)
    {
      Item_field *item=(Item_field*) pos;
      if (item->field->flags & BLOB_FLAG)
      {
	if (!(pos=new Item_copy_string(pos)))
	  goto err;
	VOID(li.replace(pos));
	if (param->copy_funcs.push_back(pos))
	  goto err;
	continue;
      }

      /* set up save buffer and change result_field to point at saved value */
      Field *field= item->field;
unknown's avatar
unknown committed
6685
      item->result_field=field->new_field(&thd->mem_root,field->table);
unknown's avatar
unknown committed
6686 6687 6688 6689 6690 6691 6692 6693 6694 6695 6696 6697 6698 6699 6700 6701 6702 6703 6704 6705 6706 6707 6708 6709
      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++;
    }
    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;
      VOID(li.replace(pos));
      if (param->copy_funcs.push_back(pos))
	goto err;
    }
  }
unknown's avatar
unknown committed
6710
  param->copy_field_end= copy;
unknown's avatar
unknown committed
6711 6712 6713
  DBUG_RETURN(0);

 err:
6714
  delete [] param->copy_field;			// This is never 0
unknown's avatar
unknown committed
6715
  param->copy_field=0;
6716
err2:
unknown's avatar
unknown committed
6717 6718 6719 6720 6721 6722 6723 6724 6725 6726 6727 6728
  DBUG_RETURN(TRUE);
}


/*
** Copy fields and null values between two tables
*/

void
copy_fields(TMP_TABLE_PARAM *param)
{
  Copy_field *ptr=param->copy_field;
unknown's avatar
unknown committed
6729
  Copy_field *end=param->copy_field_end;
unknown's avatar
unknown committed
6730 6731 6732 6733

  for ( ; ptr != end; ptr++)
    (*ptr->do_copy)(ptr);

unknown's avatar
unknown committed
6734 6735
  List_iterator_fast<Item> &it=param->copy_funcs_it;
  it.rewind();
unknown's avatar
unknown committed
6736 6737 6738 6739 6740 6741 6742 6743 6744 6745 6746 6747 6748 6749 6750 6751 6752 6753 6754 6755 6756 6757 6758 6759 6760 6761 6762 6763 6764 6765 6766 6767 6768 6769 6770 6771 6772 6773 6774 6775 6776 6777 6778
  Item_copy_string *item;
  while ((item = (Item_copy_string*) it++))
    item->copy();
}


/*****************************************************************************
** Make an array of pointer to sum_functions to speed up sum_func calculation
*****************************************************************************/

static bool
make_sum_func_list(JOIN *join,List<Item> &fields)
{
  DBUG_ENTER("make_sum_func_list");
  Item_sum **func =
    (Item_sum**) sql_alloc(sizeof(Item_sum*)*
			   (join->tmp_table_param.sum_func_count+1));
  if (!func)
    DBUG_RETURN(TRUE);
  List_iterator<Item> it(fields);
  join->sum_funcs=func;

  Item *field;
  while ((field=it++))
  {
    if (field->type() == Item::SUM_FUNC_ITEM && !field->const_item())
    {
      *func++=(Item_sum*) field;
      /* let COUNT(DISTINCT) create the temporary table */
      if (((Item_sum*) field)->setup(join->thd))
	DBUG_RETURN(TRUE);
    }
  }
  *func=0;					// End marker
  DBUG_RETURN(FALSE);
}


/*
** Change all funcs and sum_funcs to fields in tmp table
*/

static bool
6779
change_to_use_tmp_fields(List<Item> &items)
unknown's avatar
unknown committed
6780 6781 6782 6783 6784 6785 6786 6787 6788 6789 6790 6791 6792 6793 6794 6795 6796 6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808 6809 6810 6811 6812 6813 6814 6815 6816 6817 6818 6819 6820 6821 6822 6823 6824 6825 6826 6827 6828 6829 6830 6831 6832 6833 6834 6835 6836 6837 6838 6839 6840 6841 6842 6843 6844 6845 6846 6847 6848 6849 6850 6851 6852 6853 6854 6855 6856 6857 6858 6859 6860 6861 6862 6863 6864 6865 6866 6867 6868 6869 6870 6871 6872 6873 6874 6875 6876 6877 6878 6879 6880 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 6915 6916 6917 6918 6919 6920 6921 6922 6923 6924 6925 6926 6927 6928 6929 6930 6931 6932 6933 6934 6935 6936 6937 6938 6939 6940 6941 6942 6943 6944 6945 6946 6947 6948 6949 6950 6951 6952 6953 6954 6955 6956 6957 6958 6959 6960 6961 6962 6963 6964 6965 6966 6967 6968 6969 6970 6971 6972 6973
{
  List_iterator<Item> it(items);
  Item *item_field,*item;

  while ((item=it++))
  {
    Field *field;
    if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM)
      continue;
    if (item->type() == Item::FIELD_ITEM)
    {
      ((Item_field*) item)->field=
	((Item_field*) item)->result_field;
    }
    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];
	String str(buff,sizeof(buff));
	str.length(0);
	item->print(&str);
	item_field->name=sql_strmake(str.ptr(),str.length());
      }
#endif
#ifdef DELETE_ITEMS
      delete it.replace(item_field);		/*lint -e613 */
#else
      (void) it.replace(item_field);		/*lint -e613 */
#endif
    }
  }
  return FALSE;
}


/*
** Change all sum_func refs to fields to point at fields in tmp table
** Change all funcs to be fields in tmp table
*/

static bool
change_refs_to_tmp_fields(THD *thd,List<Item> &items)
{
  List_iterator<Item> it(items);
  Item *item;

  while ((item= it++))
  {
    if (item->type() == Item::SUM_FUNC_ITEM)
    {
      if (!item->const_item())
      {
	Item_sum *sum_item= (Item_sum*) item;
	if (sum_item->result_field)		// If not a const sum func
	{
	  Field *result_field=sum_item->result_field;
	  for (uint i=0 ; i < sum_item->arg_count ; i++)
	  {
	    Item *arg= sum_item->args[i];
	    if (!arg->const_item())
	    {
	      if (arg->type() == Item::FIELD_ITEM)
		((Item_field*) arg)->field= result_field++;
	      else
		sum_item->args[i]= new Item_field(result_field++);
	    }
	  }
	}
      }
    }
    else if (item->with_sum_func)
      continue;
    else if ((item->type() == Item::FUNC_ITEM ||
	      item->type() == Item::COND_ITEM) &&
	     !item->const_item())
    {						/* All funcs are stored */
#ifdef DELETE_ITEMS
      delete it.replace(new Item_field(((Item_func*) item)->result_field));
#else
      (void) it.replace(new Item_field(((Item_func*) item)->result_field));
#endif
    }
    else if (item->type() == Item::FIELD_ITEM)	/* Change refs */
    {
      ((Item_field*)item)->field=((Item_field*) item)->result_field;
    }
  }
  return thd->fatal_error;
}



/******************************************************************************
** code for calculating functions
******************************************************************************/

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++)
    (void) func->save_in_field(func->result_field);
  return;
}


static void
init_sum_functions(Item_sum **func_ptr)
{
  Item_sum *func;
  for (; (func= (Item_sum*) *func_ptr) ; func_ptr++)
    func->reset();
}


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
copy_funcs(Item_result_field **func_ptr)
{
  Item_result_field *func;
  for (; (func = *func_ptr) ; func_ptr++)
    (void) func->save_in_field(func->result_field);
  return;
}


/*****************************************************************************
** Create a condition for a const reference and add this to the
** currenct select for the table
*****************************************************************************/

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++)
  {
    Field *field=table->field[table->key_info[join_tab->ref.key].key_part[i].fieldnr-1];
    Item *value=join_tab->ref.items[i];
    cond->add(new Item_func_equal(new Item_field(field),value));
  }
  if (thd->fatal_error)
    DBUG_RETURN(TRUE);
6974 6975 6976 6977 6978

  /*
    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).
  */
unknown's avatar
unknown committed
6979 6980 6981 6982 6983 6984 6985 6986 6987 6988 6989 6990 6991 6992 6993 6994
  cond->fix_fields((THD *) 0,(TABLE_LIST *) 0);
  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);
}

/****************************************************************************
** Send a description about what how the select will be done to stdout
****************************************************************************/

unknown's avatar
unknown committed
6995
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
unknown's avatar
unknown committed
6996
			    bool distinct,const char *message)
unknown's avatar
unknown committed
6997 6998 6999
{
  List<Item> field_list;
  Item *item;
7000
  List<Item> item_list;
unknown's avatar
unknown committed
7001
  THD *thd=join->thd;
7002
  MYSQL_LOCK *save_lock;
unknown's avatar
unknown committed
7003
  SELECT_LEX *select_lex = &(join->thd->lex.select_lex);
7004
  select_result *result=join->result;
unknown's avatar
unknown committed
7005
  DBUG_ENTER("select_describe");
unknown's avatar
unknown committed
7006

7007
  /* Don't log this into the slow query log */
unknown's avatar
unknown committed
7008
  select_lex->options&= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
7009
  thd->offset_limit=0;
7010
  if (thd->lex.select == select_lex)
unknown's avatar
unknown committed
7011 7012 7013 7014
  {
    field_list.push_back(new Item_empty_string("table",NAME_LEN));
    field_list.push_back(new Item_empty_string("type",10));
    field_list.push_back(item=new Item_empty_string("possible_keys",
unknown's avatar
unknown committed
7015
						  NAME_LEN*MAX_KEY));
unknown's avatar
unknown committed
7016 7017 7018 7019 7020 7021 7022 7023 7024 7025
    item->maybe_null=1;
    field_list.push_back(item=new Item_empty_string("key",NAME_LEN));
    item->maybe_null=1;
    field_list.push_back(item=new Item_int("key_len",0,3));
    item->maybe_null=1;
    field_list.push_back(item=new Item_empty_string("ref",
						    NAME_LEN*MAX_REF_PARTS));
    item->maybe_null=1;
    field_list.push_back(new Item_real("rows",0.0,0,10));
    field_list.push_back(new Item_empty_string("Extra",255));
7026
    if (result->send_fields(field_list,1))
unknown's avatar
unknown committed
7027 7028
      return;
  }
7029

unknown's avatar
unknown committed
7030
  if (message)
unknown's avatar
unknown committed
7031
  {
7032 7033 7034 7035 7036 7037 7038 7039 7040 7041
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_empty_string("",0));
    item_list.push_back(new Item_string(message,strlen(message)));
    if (result->send_data(item_list))
      result->send_error(0,NullS);
unknown's avatar
unknown committed
7042 7043 7044 7045 7046
  }
  else
  {
    table_map used_tables=0;
    for (uint i=0 ; i < join->tables ; i++)
unknown's avatar
unknown committed
7047
    {
unknown's avatar
unknown committed
7048 7049
      JOIN_TAB *tab=join->join_tab+i;
      TABLE *table=tab->table;
7050 7051 7052 7053 7054
      char buff[512],*buff_ptr=buff;
      char buff1[512], buff2[512], bufff[512];
      String tmp1(buff1,sizeof(buff1));
      String tmp2(buff2,sizeof(buff2));
      item_list.empty();
unknown's avatar
unknown committed
7055 7056
      if (tab->type == JT_ALL && tab->select && tab->select->quick)
	tab->type= JT_RANGE;
7057 7058 7059
      item_list.push_back(new Item_string(table->table_name,strlen(table->table_name)));
      item_list.push_back(new Item_string(join_type_str[tab->type],strlen(join_type_str[tab->type])));
      tmp1.length(0); tmp2.length(0);
unknown's avatar
unknown committed
7060 7061 7062
      key_map bits;
      uint j;
      for (j=0,bits=tab->keys ; bits ; j++,bits>>=1)
unknown's avatar
unknown committed
7063
      {
unknown's avatar
unknown committed
7064 7065
	if (bits & 1)
	{
7066 7067 7068
	  if (tmp1.length())
	    tmp1.append(',');
	  tmp1.append(table->key_info[j].name);
unknown's avatar
unknown committed
7069
	}
unknown's avatar
unknown committed
7070
      }
7071 7072
      if (tmp1.length())
	item_list.push_back(new Item_string(tmp1.ptr(),tmp1.length()));
unknown's avatar
unknown committed
7073
      else
7074
	item_list.push_back(new Item_null());
unknown's avatar
unknown committed
7075
      if (tab->ref.key_parts)
unknown's avatar
unknown committed
7076
      {
7077 7078 7079
	item_list.push_back(new Item_string(table->key_info[tab->ref.key].name,
					    strlen(table->key_info[tab->ref.key].name)));
	item_list.push_back(new Item_int((int32) tab->ref.key_length));
unknown's avatar
unknown committed
7080 7081
	for (store_key **ref=tab->ref.key_copy ; *ref ; ref++)
	{
7082 7083 7084
	  if (tmp2.length())
	    tmp2.append(',');
	  tmp2.append((*ref)->name());
unknown's avatar
unknown committed
7085
	}
7086
	item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length()));
unknown's avatar
unknown committed
7087 7088 7089
      }
      else if (tab->type == JT_NEXT)
      {
7090
	item_list.push_back(new Item_string(table->key_info[tab->index].name,strlen(table->key_info[tab->index].name)));
7091
	item_list.push_back(new Item_int((int32) table->key_info[tab->index].key_length));
7092
	item_list.push_back(new Item_null());
unknown's avatar
unknown committed
7093 7094 7095
      }
      else if (tab->select && tab->select->quick)
      {
7096
	item_list.push_back(new Item_string(table->key_info[tab->select->quick->index].name,strlen(table->key_info[tab->select->quick->index].name)));
7097
	item_list.push_back(new Item_int((int32) tab->select->quick->max_used_key_length));
7098
	item_list.push_back(new Item_null());
unknown's avatar
unknown committed
7099 7100 7101
      }
      else
      {
7102 7103 7104
	item_list.push_back(new Item_null());
	item_list.push_back(new Item_null());
	item_list.push_back(new Item_null());
unknown's avatar
unknown committed
7105
      }
7106 7107
      sprintf(bufff,"%.0f",join->best_positions[i].records_read);
      item_list.push_back(new Item_string(bufff,strlen(bufff)));
unknown's avatar
unknown committed
7108 7109 7110 7111 7112 7113
      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)
7114
	item_list.push_back(new Item_string(tab->info,strlen(tab->info)));
unknown's avatar
unknown committed
7115
      else if (tab->select)
unknown's avatar
unknown committed
7116
      {
unknown's avatar
unknown committed
7117 7118 7119 7120 7121 7122 7123 7124
	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,"where used");
unknown's avatar
unknown committed
7125
      }
unknown's avatar
unknown committed
7126
      if (key_read)
unknown's avatar
unknown committed
7127
      {
unknown's avatar
unknown committed
7128 7129 7130 7131 7132
	if (buff != buff_ptr)
	{
	  buff_ptr[0]=';' ; buff_ptr[1]=' '; buff_ptr+=2;
	}
	buff_ptr=strmov(buff_ptr,"Using index");
unknown's avatar
unknown committed
7133
      }
unknown's avatar
unknown committed
7134
      if (table->reginfo.not_exists_optimize)
unknown's avatar
unknown committed
7135
      {
unknown's avatar
unknown committed
7136 7137 7138 7139 7140
	if (buff != buff_ptr)
	{
	  buff_ptr[0]=';' ; buff_ptr[1]=' '; buff_ptr+=2;
	}
	buff_ptr=strmov(buff_ptr,"Not exists");
unknown's avatar
unknown committed
7141
      }
unknown's avatar
unknown committed
7142
      if (need_tmp_table)
unknown's avatar
unknown committed
7143
      {
unknown's avatar
unknown committed
7144 7145 7146 7147 7148 7149
	need_tmp_table=0;
	if (buff != buff_ptr)
	{
	  buff_ptr[0]=';' ; buff_ptr[1]=' '; buff_ptr+=2;
	}
	buff_ptr=strmov(buff_ptr,"Using temporary");
unknown's avatar
unknown committed
7150
      }
unknown's avatar
unknown committed
7151 7152 7153 7154 7155 7156 7157 7158 7159 7160 7161 7162 7163 7164 7165 7166 7167
      if (need_order)
      {
	need_order=0;
	if (buff != buff_ptr)
	{
	  buff_ptr[0]=';' ; buff_ptr[1]=' '; buff_ptr+=2;
	}
	buff_ptr=strmov(buff_ptr,"Using filesort");
      }
      if (distinct & test_all_bits(used_tables,thd->used_tables))
      {
	if (buff != buff_ptr)
	{
	  buff_ptr[0]=';' ; buff_ptr[1]=' '; buff_ptr+=2;
	}
	buff_ptr=strmov(buff_ptr,"Distinct");
      }
7168
      item_list.push_back(new Item_string(buff,(uint) (buff_ptr - buff)));
unknown's avatar
unknown committed
7169 7170
      // For next iteration
      used_tables|=table->map;
7171 7172
      if (result->send_data(item_list))
	result->send_error(0,NullS);
unknown's avatar
unknown committed
7173
    }
unknown's avatar
unknown committed
7174
  }
unknown's avatar
unknown committed
7175
  if (!join->thd->lex.select->next)
7176 7177 7178 7179 7180 7181
  {
    save_lock=thd->lock;
    thd->lock=(MYSQL_LOCK *)0;
    result->send_eof();
    thd->lock=save_lock;
  }
unknown's avatar
unknown committed
7182 7183 7184 7185
  DBUG_VOID_RETURN;
}


7186
static void describe_info(THD *thd, const char *info)
unknown's avatar
unknown committed
7187 7188 7189 7190
{
  List<Item> field_list;
  String *packet= &thd->packet;

7191
  /* Don't log this into the slow query log */
7192
  thd->lex.select_lex.options&= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
unknown's avatar
unknown committed
7193 7194 7195 7196 7197 7198 7199 7200
  field_list.push_back(new Item_empty_string("Comment",80));
  if (send_fields(thd,field_list,1))
    return; /* purecov: inspected */
  packet->length(0);
  net_store_data(packet,info);
  if (!my_net_write(&thd->net,(char*) packet->ptr(),packet->length()))
    send_eof(&thd->net);
}