diff options
Diffstat (limited to 'sql/table.h')
| -rw-r--r-- | sql/table.h | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/sql/table.h b/sql/table.h index 54c820d391c..086df5f28f8 100644 --- a/sql/table.h +++ b/sql/table.h @@ -299,6 +299,12 @@ typedef struct st_table_share /* Information for one open table */ +enum index_hint_type +{ + INDEX_HINT_IGNORE, + INDEX_HINT_USE, + INDEX_HINT_FORCE +}; struct st_table { st_table() {} /* Remove gcc warning */ @@ -318,8 +324,12 @@ struct st_table { byte *write_row_record; /* Used as optimisation in THD::write_row */ byte *insert_values; /* used by INSERT ... UPDATE */ - key_map quick_keys, used_keys; - + /* + Map of keys that can be used to retrieve all data from this table + needed by the query without reading the row. + */ + key_map covering_keys; + key_map quick_keys, merge_keys; /* A set of keys that can be used in the query that references this table. @@ -332,7 +342,10 @@ struct st_table { The set is implemented as a bitmap. */ key_map keys_in_use_for_query; - key_map merge_keys; + /* Map of keys that can be used to calculate GROUP BY without sorting */ + key_map keys_in_use_for_group_by; + /* Map of keys that can be used to calculate ORDER BY without sorting */ + key_map keys_in_use_for_order_by; KEY *key_info; /* data of keys in database */ Field *next_number_field; /* Set if next_number is activated */ @@ -666,6 +679,7 @@ public: (TABLE_LIST::join_using_fields != NULL) */ +class index_hint; typedef struct st_table_list { st_table_list() {} /* Remove gcc warning */ @@ -722,7 +736,7 @@ typedef struct st_table_list */ struct st_table_list *next_name_resolution_table; /* Index names in a "... JOIN ... USE/IGNORE INDEX ..." clause. */ - List<String> *use_index, *ignore_index; + List<index_hint> *index_hints; TABLE *table; /* opened table */ uint table_id; /* table id (from binlog) for opened table */ /* @@ -896,6 +910,13 @@ typedef struct st_table_list void reinit_before_use(THD *thd); Item_subselect *containing_subselect(); + /* + Compiles the tagged hints list and fills up st_table::keys_in_use_for_query, + st_table::keys_in_use_for_group_by, st_table::keys_in_use_for_order_by, + st_table::force_index and st_table::covering_keys. + */ + bool process_index_hints(TABLE *table); + private: bool prep_check_option(THD *thd, uint8 check_opt_type); bool prep_where(THD *thd, Item **conds, bool no_where_clause); |