diff options
Diffstat (limited to 'sql/handler.h')
| -rw-r--r-- | sql/handler.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/sql/handler.h b/sql/handler.h index 749c1aaf497..674b58aacd7 100644 --- a/sql/handler.h +++ b/sql/handler.h @@ -949,6 +949,10 @@ struct handler_iterator { }; class handler; +class group_by_handler; +typedef class st_select_lex SELECT_LEX; +typedef struct st_order ORDER; + /* handlerton is a singleton structure - one instance per storage engine - to provide access to storage engine functionality that works on the @@ -1251,6 +1255,24 @@ struct handlerton */ const char **tablefile_extensions; // by default - empty list + /********************************************************************** + Functions to intercept queries + **********************************************************************/ + + /* + Create and return a group_by_handler, if the storage engine can execute + the summary / group by query. + If the storage engine can't do that, return NULL. + + This is only called for SELECT's where all tables are from the same + storage engine. + */ + group_by_handler *(*create_group_by)(THD *thd, SELECT_LEX *select_lex, + List<Item> *fields, + TABLE_LIST *table_list, ORDER *group_by, + ORDER *order_by, Item *where, + Item *having); + /********************************************************************* Table discovery API. It allows the server to "discover" tables that exist in the storage @@ -4080,6 +4102,7 @@ protected: }; #include "multi_range_read.h" +#include "group_by_handler.h" bool key_uses_partial_cols(TABLE_SHARE *table, uint keyno); |