diff options
Diffstat (limited to 'sql/sql_lex.h')
| -rw-r--r-- | sql/sql_lex.h | 81 |
1 files changed, 71 insertions, 10 deletions
diff --git a/sql/sql_lex.h b/sql/sql_lex.h index 7fd60cbfa58..0e91b2a786b 100644 --- a/sql/sql_lex.h +++ b/sql/sql_lex.h @@ -209,6 +209,47 @@ enum tablespace_op_type }; /* + String names used to print a statement with index hints. + Keep in sync with index_hint_type. +*/ +extern const char * index_hint_type_name[]; +typedef byte index_clause_map; + +/* + Bits in index_clause_map : one for each possible FOR clause in + USE/FORCE/IGNORE INDEX index hint specification +*/ +#define INDEX_HINT_MASK_JOIN (1) +#define INDEX_HINT_MASK_GROUP (1 << 1) +#define INDEX_HINT_MASK_ORDER (1 << 2) + +#define INDEX_HINT_MASK_ALL (INDEX_HINT_MASK_JOIN | INDEX_HINT_MASK_GROUP | \ + INDEX_HINT_MASK_ORDER) + +/* Single element of an USE/FORCE/IGNORE INDEX list specified as a SQL hint */ +class index_hint : public Sql_alloc +{ +public: + /* The type of the hint : USE/FORCE/IGNORE */ + enum index_hint_type type; + /* Where the hit applies to. A bitmask of INDEX_HINT_MASK_<place> values */ + index_clause_map clause; + /* + The index name. Empty (str=NULL) name represents an empty list + USE INDEX () clause + */ + LEX_STRING key_name; + + index_hint (enum index_hint_type type_arg, index_clause_map clause_arg, + char *str, uint length) : + type(type_arg), clause(clause_arg) + { + key_name.str= str; + key_name.length= length; + } +}; + +/* The state of the lex parsing for selects master and slaves are pointers to select_lex. @@ -386,15 +427,12 @@ public: virtual uint get_in_sum_expr(); virtual TABLE_LIST* get_table_list(); virtual List<Item>* get_item_list(); - virtual List<String>* get_use_index(); - virtual List<String>* get_ignore_index(); virtual ulong get_table_join_options(); virtual TABLE_LIST *add_table_to_list(THD *thd, Table_ident *table, LEX_STRING *alias, ulong table_options, thr_lock_type flags= TL_UNLOCK, - List<String> *use_index= 0, - List<String> *ignore_index= 0, + List<index_hint> *hints= 0, LEX_STRING *option= 0); virtual void set_lock_for_tables(thr_lock_type lock_type) {} @@ -521,8 +559,7 @@ public: SQL_LIST table_list; SQL_LIST group_list; /* GROUP BY clause. */ List<Item> item_list; /* list of fields & expressions */ - List<String> interval_list, use_index, *use_index_ptr, - ignore_index, *ignore_index_ptr; + List<String> interval_list; bool is_item_list_lookup; /* Usualy it is pointer to ftfunc_list_alloc, but in union used to create fake @@ -645,8 +682,7 @@ public: LEX_STRING *alias, ulong table_options, thr_lock_type flags= TL_UNLOCK, - List<String> *use_index= 0, - List<String> *ignore_index= 0, + List<index_hint> *hints= 0, LEX_STRING *option= 0); TABLE_LIST* get_table_list(); bool init_nested_join(THD *thd); @@ -655,8 +691,6 @@ public: void add_joined_table(TABLE_LIST *table); TABLE_LIST *convert_right_join(); List<Item>* get_item_list(); - List<String>* get_use_index(); - List<String>* get_ignore_index(); ulong get_table_join_options(); void set_lock_for_tables(thr_lock_type lock_type); inline void init_order() @@ -696,6 +730,33 @@ public: select lexes. */ void cleanup_all_joins(bool full); + + void set_index_hint_type(enum index_hint_type type, index_clause_map clause); + + /* + Add a index hint to the tagged list of hints. The type and clause of the + hint will be the current ones (set by set_index_hint()) + */ + bool add_index_hint (THD *thd, char *str, uint length); + + /* make a list to hold index hints */ + void alloc_index_hints (THD *thd); + /* read and clear the index hints */ + List<index_hint>* pop_index_hints(void) + { + List<index_hint> *hints= index_hints; + index_hints= NULL; + return hints; + } + + void clear_index_hints(void) { index_hints= NULL; } + +private: + /* current index hint kind. used in filling up index_hints */ + enum index_hint_type current_index_hint_type; + index_clause_map current_index_hint_clause; + /* a list of USE/FORCE/IGNORE INDEX */ + List<index_hint> *index_hints; }; typedef class st_select_lex SELECT_LEX; |