diff options
Diffstat (limited to 'sql/sql_select.h')
| -rw-r--r-- | sql/sql_select.h | 86 |
1 files changed, 77 insertions, 9 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h index 34eaa7e272d..a1487693b79 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -75,23 +75,32 @@ typedef struct st_join_cache { /* ** The structs which holds the join connections and join states */ - enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF, JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL, - JT_UNIQUE_SUBQUERY, JT_INDEX_SUBQUERY}; + JT_UNIQUE_SUBQUERY, JT_INDEX_SUBQUERY, JT_INDEX_MERGE}; class JOIN; +typedef int (*Next_select_func)(JOIN *,struct st_join_table *,bool); +typedef int (*Read_record_func)(struct st_join_table *tab); + + typedef struct st_join_table { TABLE *table; KEYUSE *keyuse; /* pointer to first used key */ SQL_SELECT *select; COND *select_cond; - QUICK_SELECT *quick; - Item *on_expr; + QUICK_SELECT_I *quick; + Item *on_expr; /* associated on expression */ + st_join_table *first_inner; /* first inner table for including outerjoin */ + bool found; /* true after all matches or null complement */ + bool not_null_compl;/* true before null complement is added */ + st_join_table *last_inner; /* last table table for embedding outer join */ + st_join_table *first_upper; /* first inner table for embedding outer join */ + st_join_table *first_unmatched; /* used for optimization purposes only */ const char *info; - int (*read_first_record)(struct st_join_table *tab); - int (*next_select)(JOIN *,struct st_join_table *,bool); + Read_record_func read_first_record; + Next_select_func next_select; READ_RECORD read_record; double worst_seeks; key_map const_keys; /* Keys with constant part */ @@ -116,6 +125,7 @@ typedef struct st_join_table { typedef struct st_position /* Used in find_best */ { double records_read; + double read_time; JOIN_TAB *table; KEYUSE *key; } POSITION; @@ -133,8 +143,9 @@ typedef struct st_rollup class JOIN :public Sql_alloc { public: - JOIN_TAB *join_tab,**best_ref,**map2table; - JOIN_TAB *join_tab_save; //saved join_tab for subquery reexecution + JOIN_TAB *join_tab,**best_ref; + JOIN_TAB **map2table; // mapping between table indexes and JOIN_TABs + JOIN_TAB *join_tab_save; // saved join_tab for subquery reexecution TABLE **table,**all_tables,*sort_by_table; uint tables,const_tables; uint send_group_parts; @@ -142,6 +153,16 @@ class JOIN :public Sql_alloc bool do_send_rows; table_map const_table_map,found_const_table_map,outer_join; ha_rows send_records,found_records,examined_rows,row_limit, select_limit; + /* + Used to fetch no more than given amount of rows per one + fetch operation of server side cursor. + The value is checked in end_send and end_send_group in fashion, similar + to offset_limit_cnt: + - fetch_limit= HA_POS_ERROR if there is no cursor. + - when we open a cursor, we set fetch_limit to 0, + - on each fetch iteration we add num_rows to fetch to fetch_limit + */ + ha_rows fetch_limit; POSITION positions[MAX_TABLES+1],best_positions[MAX_TABLES+1]; double best_read; List<Item> *fields; @@ -199,8 +220,10 @@ class JOIN :public Sql_alloc ORDER *order, *group_list, *proc_param; //hold parameters of mysql_select COND *conds; // ---"--- Item *conds_history; // store WHERE for explain - TABLE_LIST *tables_list; //hold 'tables' parameter of mysql_selec + TABLE_LIST *tables_list; //hold 'tables' parameter of mysql_select + List<TABLE_LIST> *join_list; // list of joined tables in reverse order SQL_SELECT *select; //created in optimisation phase + JOIN_TAB *return_tab; //used only for outer joins Item **ref_pointer_array; //used pointer reference for this select // Copy of above to be used with different lists Item **items0, **items1, **items2, **items3, **current_ref_pointer_array; @@ -224,11 +247,13 @@ class JOIN :public Sql_alloc table= 0; tables= 0; const_tables= 0; + join_list= 0; sort_and_group= 0; first_record= 0; do_send_rows= 1; send_records= 0; found_records= 0; + fetch_limit= HA_POS_ERROR; examined_rows= 0; exec_tmp_table1= 0; exec_tmp_table2= 0; @@ -254,6 +279,7 @@ class JOIN :public Sql_alloc fields_list= fields_arg; error= 0; select= 0; + return_tab= 0; ref_pointer_array= items0= items1= items2= items3= 0; ref_pointer_array_size= 0; zero_result_cause= 0; @@ -308,6 +334,44 @@ class JOIN :public Sql_alloc }; +/* + Server-side cursor (now stands only for basic read-only cursor) + See class implementation in sql_select.cc +*/ + +class Cursor: public Sql_alloc, public Item_arena +{ + JOIN *join; + SELECT_LEX_UNIT *unit; + + TABLE *open_tables; + MYSQL_LOCK *lock; + TABLE *derived_tables; + /* List of items created during execution */ + ulong query_id; +public: + select_send result; + + /* Temporary implementation as now we replace THD state by value */ + /* Save THD state into cursor */ + void init_from_thd(THD *thd); + /* Restore THD from cursor to continue cursor execution */ + void init_thd(THD *thd); + /* bzero cursor state in THD */ + void reset_thd(THD *thd); + + int open(JOIN *join); + int fetch(ulong num_rows); + void reset() { join= 0; } + bool is_open() const { return join != 0; } + void close(); + + void set_unit(SELECT_LEX_UNIT *unit_arg) { unit= unit_arg; } + Cursor() :join(0), unit(0) {} + ~Cursor(); +}; + + typedef struct st_select_check { uint const_ref,reg_ref; } SELECT_CHECK; @@ -332,10 +396,14 @@ void copy_fields(TMP_TABLE_PARAM *param); void copy_funcs(Item **func_ptr); bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param, int error, bool ignore_last_dupp_error); +uint find_shortest_key(TABLE *table, const key_map *usable_keys); /* functions from opt_sum.cc */ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds); +/* from sql_delete.cc, used by opt_range.cc */ +extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b); + /* class to copying an field/item to a key struct */ class store_key :public Sql_alloc |