diff options
Diffstat (limited to 'sql/item.h')
| -rw-r--r-- | sql/item.h | 77 |
1 files changed, 70 insertions, 7 deletions
diff --git a/sql/item.h b/sql/item.h index 9574bdc63bf..64e60e7fec2 100644 --- a/sql/item.h +++ b/sql/item.h @@ -569,6 +569,7 @@ typedef bool (Item::*Item_processor) (void *arg); typedef bool (Item::*Item_analyzer) (uchar **argp); typedef Item* (Item::*Item_transformer) (THD *thd, uchar *arg); typedef void (*Cond_traverser) (const Item *item, void *arg); +typedef bool (Item::*Pushdown_checker) (uchar *arg); struct st_cond_statistic; @@ -601,6 +602,7 @@ public: String_copier_for_item(THD *thd): m_thd(thd) { } }; + class Item: public Value_source, public Type_all_attributes { @@ -1647,7 +1649,15 @@ public: or can be converted to such an exression using equalities. Not to be used for AND/OR formulas. */ - virtual bool excl_dep_on_grouping_fields(st_select_lex *sel) { return false; } + virtual bool excl_dep_on_grouping_fields(st_select_lex *sel) + { return false; } + /* + TRUE if the expression depends only on fields from the left part of + IN subquery or can be converted to such an expression using equalities. + Not to be used for AND/OR formulas. + */ + virtual bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) + { return false; } virtual bool switch_to_nullable_fields_processor(void *arg) { return 0; } virtual bool find_function_processor (void *arg) { return 0; } @@ -1825,8 +1835,12 @@ public: { return this; } virtual Item *derived_field_transformer_for_where(THD *thd, uchar *arg) { return this; } - virtual Item *derived_grouping_field_transformer_for_where(THD *thd, - uchar *arg) + virtual Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) + { return this; } + /* Now is not used. */ + virtual Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) + { return this; } + virtual Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) { return this; } virtual Item *in_predicate_to_in_subs_transformer(THD *thd, uchar *arg) { return this; } @@ -2023,6 +2037,33 @@ public: { marker &= ~EXTRACTION_MASK; } + void check_pushable_cond(Pushdown_checker excl_dep_func, uchar *arg); + bool pushable_cond_checker_for_derived(uchar *arg) + { + return excl_dep_on_table(*((table_map *)arg)); + } + bool pushable_cond_checker_for_subquery(uchar *arg) + { + return excl_dep_on_in_subq_left_part((Item_in_subselect *)arg); + } + Item *get_corresponding_field_in_insubq(Item_in_subselect *subq_pred); + Item *build_pushable_cond(THD *thd, + Pushdown_checker checker, + uchar *arg); + /* + Checks if this item depends only on the arg table + */ + bool pushable_equality_checker_for_derived(uchar *arg) + { + return (used_tables() == *((table_map *)arg)); + } + /* + Checks if this item consists in the left part of arg IN subquery predicate + */ + bool pushable_equality_checker_for_subquery(uchar *arg) + { + return get_corresponding_field_in_insubq((Item_in_subselect *)arg); + } }; MEM_ROOT *get_thd_memroot(THD *thd); @@ -2151,6 +2192,17 @@ protected: } return true; } + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) + { + for (uint i= 0; i < arg_count; i++) + { + if (args[i]->const_item()) + continue; + if (!args[i]->excl_dep_on_in_subq_left_part(subq_pred)) + return false; + } + return true; + } public: Item_args(void) :args(NULL), arg_count(0) @@ -3046,10 +3098,13 @@ public: virtual Item *update_value_transformer(THD *thd, uchar *select_arg); Item *derived_field_transformer_for_having(THD *thd, uchar *arg); Item *derived_field_transformer_for_where(THD *thd, uchar *arg); - Item *derived_grouping_field_transformer_for_where(THD *thd, uchar *arg); + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg); + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg); + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg); virtual void print(String *str, enum_query_type query_type); bool excl_dep_on_table(table_map tab_map); bool excl_dep_on_grouping_fields(st_select_lex *sel); + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred); bool cleanup_excluding_fields_processor(void *arg) { return field ? 0 : cleanup_processor(arg); } bool cleanup_excluding_const_fields_processor(void *arg) @@ -4874,6 +4929,8 @@ public: } bool excl_dep_on_grouping_fields(st_select_lex *sel) { return (*ref)->excl_dep_on_grouping_fields(sel); } + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) + { return (*ref)->excl_dep_on_in_subq_left_part(subq_pred); } bool cleanup_excluding_fields_processor(void *arg) { Item *item= real_item(); @@ -5188,10 +5245,12 @@ public: } bool excl_dep_on_table(table_map tab_map); bool excl_dep_on_grouping_fields(st_select_lex *sel); + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred); Item *derived_field_transformer_for_having(THD *thd, uchar *arg); Item *derived_field_transformer_for_where(THD *thd, uchar *arg); - Item *derived_grouping_field_transformer_for_where(THD *thd, - uchar *arg); + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg); + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg); + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg); void save_val(Field *to) { @@ -6110,7 +6169,11 @@ public: { return convert_to_basic_const_item(thd); } Item *derived_field_transformer_for_where(THD *thd, uchar *arg) { return convert_to_basic_const_item(thd); } - Item *derived_grouping_field_transformer_for_where(THD *thd, uchar *arg) + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) + { return convert_to_basic_const_item(thd); } + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) + { return convert_to_basic_const_item(thd); } + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) { return convert_to_basic_const_item(thd); } }; |