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MWL#89: Cost-based choice between Materialization and IN->EXISTS transformation

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Fixes for multiple problems/bugs/test failures that resulted from moving
subquery optimization from the execution phase to the optimization phase.
This commit is contained in:
unknown
2010-09-05 18:43:47 +03:00
parent aa195b2570
commit 18ad3bdc2f
14 changed files with 528 additions and 269 deletions
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14
sql/sql_select.h
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@ -1573,8 +1573,15 @@ public:
bool union_part; ///< this subselect is part of union
bool optimized; ///< flag to avoid double optimization in EXPLAIN
bool initialized; ///< flag to avoid double init_execution calls
Array<Item_in_subselect> sj_subselects;
/*
Additional WHERE and HAVING predicates to be considered for IN=>EXISTS
subquery transformation of a JOIN object.
*/
Item *in_to_exists_where;
Item *in_to_exists_having;
/* Temporary tables used to weed-out semi-join duplicates */
List<TABLE> sj_tmp_tables;
@ -1649,6 +1656,7 @@ public:
ref_pointer_array_size= 0;
zero_result_cause= 0;
optimized= 0;
initialized= 0;
cond_equal= 0;
group_optimized_away= 0;
@ -1662,6 +1670,8 @@ public:
no_const_tables= FALSE;
first_select= sub_select;
in_to_exists_where= NULL;
in_to_exists_having= NULL;
}
int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num,
@ -1670,12 +1680,13 @@ public:
SELECT_LEX_UNIT *unit);
int optimize();
int reinit();
int init_execution();
void exec();
int destroy();
void restore_tmp();
bool alloc_func_list();
bool flatten_subqueries();
bool setup_subquery_materialization();
bool optimize_unflattened_subqueries();
bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
bool before_group_by, bool recompute= FALSE);
@ -1735,6 +1746,7 @@ public:
NULL : join_tab+const_tables;
}
bool setup_subquery_caches();
bool choose_subquery_plan();
private:
/**
TRUE if the query contains an aggregate function but has no GROUP