diff options
Diffstat (limited to 'sql/item_subselect.h')
| -rw-r--r-- | sql/item_subselect.h | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/sql/item_subselect.h b/sql/item_subselect.h index 8d590bc4273..a0db43fe9fe 100644 --- a/sql/item_subselect.h +++ b/sql/item_subselect.h @@ -46,16 +46,17 @@ protected: < child_join->prepare < engine->prepare *ref= substitution; + substitution= NULL; < Item_subselect::fix_fields */ - Item *substitution; public: + Item *substitution; /* unit of subquery */ st_select_lex_unit *unit; -protected: Item *expr_cache; /* engine that perform execution of subselect (single select or union) */ subselect_engine *engine; +protected: /* old engine if engine was changed */ subselect_engine *old_engine; /* cache of used external tables */ @@ -148,6 +149,7 @@ public: bool mark_as_dependent(THD *thd, st_select_lex *select, Item *item); void fix_after_pullout(st_select_lex *new_parent, Item **ref); void recalc_used_tables(st_select_lex *new_parent, bool after_pullout); + virtual int optimize(); virtual bool exec(); virtual void fix_length_and_dec(); table_map used_tables() const; @@ -351,7 +353,9 @@ protected: all JOIN in UNION */ Item *expr; +public: Item_in_optimizer *optimizer; +protected: bool was_null; bool abort_on_null; public: @@ -397,6 +401,16 @@ public: }; enum_exec_method exec_method; + /* + TRUE<=>this is a flattenable semi-join, false overwise. + */ + bool is_flattenable_semijoin; + + /* + Cost to populate the temporary table (set on if-needed basis). + */ + //double startup_cost; + bool *get_cond_guard(int i) { return pushed_cond_guards ? pushed_cond_guards + i : NULL; @@ -446,7 +460,7 @@ public: bool fix_fields(THD *thd, Item **ref); void fix_after_pullout(st_select_lex *new_parent, Item **ref); void update_used_tables(); - bool setup_engine(); + bool setup_engine(bool dont_switch_arena); bool init_left_expr_cache(); /* Inform 'this' that it was computed, and contains a valid result. */ void set_first_execution() { if (first_execution) first_execution= FALSE; } @@ -522,6 +536,7 @@ public: THD * get_thd() { return thd; } virtual int prepare()= 0; virtual void fix_length_and_dec(Item_cache** row)= 0; + virtual int optimize() { DBUG_ASSERT(0); return 0; } /* Execute the engine @@ -752,7 +767,7 @@ inline bool Item_subselect::is_uncacheable() const class subselect_hash_sj_engine : public subselect_engine { -protected: +public: /* The table into which the subquery is materialized. */ TABLE *tmp_table; /* TRUE if the subquery was materialized into a temp table. */ @@ -764,14 +779,16 @@ protected: of subselect_single_select_engine::[prepare | cols]. */ subselect_single_select_engine *materialize_engine; +protected: /* The engine used to compute the IN predicate. */ subselect_engine *lookup_engine; /* QEP to execute the subquery and materialize its result into a temporary table. Created during the first call to exec(). */ +public: JOIN *materialize_join; - +protected: /* Keyparts of the only non-NULL composite index in a rowid merge. */ MY_BITMAP non_null_key_parts; /* Keyparts of the single column indexes with NULL, one keypart per index. */ @@ -784,7 +801,9 @@ protected: IN results because index lookups sometimes match values that are actually not equal to the search key in SQL terms. */ +public: Item_cond_and *semi_join_conds; +protected: /* Possible execution strategies that can be used to compute hash semi-join.*/ enum exec_strategy { UNDEFINED, @@ -818,10 +837,11 @@ public: {} ~subselect_hash_sj_engine(); - bool init_permanent(List<Item> *tmp_columns); + bool init_permanent(List<Item> *tmp_columns, uint subquery_id); bool init_runtime(); void cleanup(); int prepare() { return 0; } /* Override virtual function in base class. */ + int optimize(); int exec(); virtual void print(String *str, enum_query_type query_type); uint cols() |