diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 52 |
1 files changed, 33 insertions, 19 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index db3a0c90141..2d8ea72ed51 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -4910,13 +4910,13 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) JOIN_TAB *tab=join->join_tab+i; JOIN_TAB *first_inner_tab= tab->first_inner; table_map current_map= tab->table->map; + bool use_quick_range=0; /* Following force including random expression in last table condition. It solve problem with select like SELECT * FROM t1 WHERE rand() > 0.5 */ if (i == join->tables-1) current_map|= OUTER_REF_TABLE_BIT | RAND_TABLE_BIT; - bool use_quick_range=0; used_tables|=current_map; if (tab->type == JT_REF && tab->quick && @@ -4935,11 +4935,26 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) COND *tmp=make_cond_for_table(cond,used_tables,current_map); 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 + if (tab->type != JT_ALL) + { + /* + Don't use the quick method + We come here in the case where we have 'key=constant' and + the test is removed by make_cond_for_table() + */ + delete tab->quick; + tab->quick= 0; + } + else + { + /* + Hack to handle the case where we only refer to a table + in the ON part of an OUTER JOIN. In this case we want the code + below to check if we should use 'quick' instead. + */ + tmp= new Item_int((longlong) 1,1); // Always true + } + } if (tmp) { @@ -5989,6 +6004,7 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top) NESTED_JOIN *nested_join; TABLE_LIST *prev_table= 0; List_iterator<TABLE_LIST> li(*join_list); + DBUG_ENTER("simplify_joins"); /* Try to simplify join operations from join_list. @@ -6122,36 +6138,34 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top) li.replace(nested_join->join_list); } } - return conds; + DBUG_RETURN(conds); } static COND * optimize_cond(JOIN *join, COND *conds, Item::cond_result *cond_value) { + THD *thd= join->thd; SELECT_LEX *select= thd->lex->current_select; DBUG_ENTER("optimize_cond"); - THD *thd= join->thd; - SELECT_LEX *select= thd->lex->current_select; if (select->first_cond_optimization) { - Item_arena *arena, backup; + /* + The following code will allocate the new items in a permanent + MEMROOT for prepared statements and stored procedures. + */ + + Item_arena *arena=thd->current_arena, backup; select->first_cond_optimization= 0; - arena= thd->current_arena; - if (!arena->is_stmt_prepare()) - arena= 0; - else - thd->set_n_backup_item_arena(arena, &backup); + thd->set_n_backup_item_arena(arena, &backup); /* Convert all outer joins to inner joins if possible */ conds= simplify_joins(join, join->join_list, conds, TRUE); select->prep_where= conds ? conds->copy_andor_structure(thd) : 0; - select->first_cond_optimization= 0; - if (arena) - thd->restore_backup_item_arena(arena, &backup); + thd->restore_backup_item_arena(arena, &backup); } if (!conds) @@ -6161,7 +6175,7 @@ optimize_cond(JOIN *join, COND *conds, Item::cond_result *cond_value) } else { - DBUG_EXECUTE("where", print_where(conds, "after negation elimination");); + DBUG_EXECUTE("where", print_where(conds, "original");); /* change field = field to field = const for each found field = const */ propagate_cond_constants((I_List<COND_CMP> *) 0,conds,conds); /* |