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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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8
sql/sql_lex.h
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@ -439,6 +439,7 @@ public:
st_select_lex_node(): linkage(UNSPECIFIED_TYPE) {}
virtual ~st_select_lex_node() {}
inline st_select_lex_node* get_master() { return master; }
inline void set_master(st_select_lex_node* master_arg) { master= master_arg; }
virtual void init_query();
virtual void init_select();
void include_down(st_select_lex_node *upper);
@ -446,6 +447,7 @@ public:
void include_standalone(st_select_lex_node *sel, st_select_lex_node **ref);
void include_global(st_select_lex_node **plink);
void exclude();
void exclude_from_tree();
virtual st_select_lex_unit* master_unit()= 0;
virtual st_select_lex* outer_select()= 0;
@ -839,6 +841,12 @@ public:
void clear_index_hints(void) { index_hints= NULL; }
bool is_part_of_union() { return master_unit()->is_union(); }
/*
Optimize all subqueries that have not been flattened into semi-joins.
This functionality is a method of SELECT_LEX instead of JOIN because
some SQL statements as DELETE do not have a corresponding JOIN object.
*/
bool optimize_unflattened_subqueries();
private:
/* current index hint kind. used in filling up index_hints */
enum index_hint_type current_index_hint_type;