diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 51 |
1 files changed, 36 insertions, 15 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 1c8b6a75cfe..0e3856240ca 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1,4 +1,4 @@ -/* Copyright (C) 2000-2006 MySQL AB +/* Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc. 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 @@ -114,7 +114,7 @@ static COND* substitute_for_best_equal_field(COND *cond, void *table_join_idx); static COND *simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top); -static bool check_interleaving_with_nj(JOIN_TAB *last, JOIN_TAB *next); +static bool check_interleaving_with_nj(JOIN_TAB *next); static void restore_prev_nj_state(JOIN_TAB *last); static void reset_nj_counters(List<TABLE_LIST> *join_list); static uint build_bitmap_for_nested_joins(List<TABLE_LIST> *join_list, @@ -1677,14 +1677,22 @@ JOIN::exec() (zero_result_cause?zero_result_cause:"No tables used")); else { - result->send_fields(*columns_list, - Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF); + if (result->send_fields(*columns_list, + Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF)) + { + DBUG_VOID_RETURN; + } /* We have to test for 'conds' here as the WHERE may not be constant even if we don't have any tables for prepared statements or if conds uses something like 'rand()'. + If the HAVING clause is either impossible or always true, then + JOIN::having is set to NULL by optimize_cond. + In this case JOIN::exec must check for JOIN::having_value, in the + same way it checks for JOIN::cond_value. */ if (cond_value != Item::COND_FALSE && + having_value != Item::COND_FALSE && (!conds || conds->val_int()) && (!having || having->val_int())) { @@ -2606,7 +2614,7 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables, COND *conds, if (s->dependent & table->map) s->dependent |= table->reginfo.join_tab->dependent; } - if (s->dependent) + if (outer_join & s->table->map) s->table->maybe_null= 1; } /* Catch illegal cross references for outer joins */ @@ -4908,6 +4916,18 @@ greedy_search(JOIN *join, */ join->positions[idx]= best_pos; + /* + Update the interleaving state after extending the current partial plan + with a new table. + We are doing this here because best_extension_by_limited_search reverts + the interleaving state to the one of the non-extended partial plan + on exit. + */ + IF_DBUG(bool is_interleave_error= ) + check_interleaving_with_nj (best_table); + /* This has been already checked by best_extension_by_limited_search */ + DBUG_ASSERT(!is_interleave_error); + /* find the position of 'best_table' in 'join->best_ref' */ best_idx= idx; JOIN_TAB *pos= join->best_ref[best_idx]; @@ -4925,7 +4945,7 @@ greedy_search(JOIN *join, --size_remain; ++idx; - DBUG_EXECUTE("opt", print_plan(join, join->tables, + DBUG_EXECUTE("opt", print_plan(join, idx, record_count, read_time, read_time, "extended");); } while (TRUE); @@ -5083,7 +5103,7 @@ best_extension_by_limited_search(JOIN *join, table_map real_table_bit= s->table->map; if ((remaining_tables & real_table_bit) && !(remaining_tables & s->dependent) && - (!idx || !check_interleaving_with_nj(join->positions[idx-1].table, s))) + (!idx || !check_interleaving_with_nj(s))) { double current_record_count, current_read_time; @@ -5229,7 +5249,7 @@ find_best(JOIN *join,table_map rest_tables,uint idx,double record_count, { table_map real_table_bit=s->table->map; if ((rest_tables & real_table_bit) && !(rest_tables & s->dependent) && - (!idx|| !check_interleaving_with_nj(join->positions[idx-1].table, s))) + (!idx|| !check_interleaving_with_nj(s))) { double records, best; best_access_path(join, s, thd, rest_tables, idx, record_count, @@ -8809,9 +8829,6 @@ static void reset_nj_counters(List<TABLE_LIST> *join_list) the partial join order. @endverbatim - @param join Join being processed - @param last_tab Last table in current partial join order (this function is - not called for empty partial join orders) @param next_tab Table we're going to extend the current partial join with @retval @@ -8821,10 +8838,10 @@ static void reset_nj_counters(List<TABLE_LIST> *join_list) TRUE Requested join order extension not allowed. */ -static bool check_interleaving_with_nj(JOIN_TAB *last_tab, JOIN_TAB *next_tab) +static bool check_interleaving_with_nj(JOIN_TAB *next_tab) { TABLE_LIST *next_emb= next_tab->table->pos_in_table_list->embedding; - JOIN *join= last_tab->join; + JOIN *join= next_tab->join; if (join->cur_embedding_map & ~next_tab->embedding_map) { @@ -14061,6 +14078,7 @@ join_init_cache(THD *thd,JOIN_TAB *tables,uint table_count) length=0; for (i=0 ; i < table_count ; i++) { + bool have_bit_fields= FALSE; uint null_fields=0,used_fields; Field **f_ptr,*field; MY_BITMAP *read_set= tables[i].table->read_set; @@ -14075,13 +14093,16 @@ join_init_cache(THD *thd,JOIN_TAB *tables,uint table_count) length+=field->fill_cache_field(copy); if (copy->blob_field) (*blob_ptr++)=copy; - if (field->maybe_null()) + if (field->real_maybe_null()) null_fields++; + if (field->type() == MYSQL_TYPE_BIT && + ((Field_bit*)field)->bit_len) + have_bit_fields= TRUE; copy++; } } /* Copy null bits from table */ - if (null_fields && tables[i].table->s->null_fields) + if (null_fields || have_bit_fields) { /* must copy null bits */ copy->str= tables[i].table->null_flags; copy->length= tables[i].table->s->null_bytes; |