diff options
Diffstat (limited to 'sql/sql_select.h')
| -rw-r--r-- | sql/sql_select.h | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h index 352378b7dff..bcf9ff6ff1e 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -166,11 +166,23 @@ class JOIN :public Sql_alloc JOIN *tmp_join; // copy of this JOIN to be used with temporary tables ROLLUP rollup; // Used with rollup - bool select_distinct, //Is select distinct? - no_order, simple_order, simple_group, - skip_sort_order, need_tmp, - hidden_group_fields, - buffer_result; + bool select_distinct; // Set if SELECT DISTINCT + + /* + simple_xxxxx is set if ORDER/GROUP BY doesn't include any references + to other tables than the first non-constant table in the JOIN. + It's also set if ORDER/GROUP BY is empty. + */ + bool simple_order, simple_group; + /* + Is set only in case if we have a GROUP BY clause + and no ORDER BY after constant elimination of 'order'. + */ + bool no_order; + /* Is set if we have a GROUP BY and we have ORDER BY on a constant. */ + bool skip_sort_order; + + bool need_tmp, hidden_group_fields, buffer_result; DYNAMIC_ARRAY keyuse; Item::cond_result cond_value; List<Item> all_fields; // to store all fields that used in query @@ -196,14 +208,14 @@ class JOIN :public Sql_alloc bool union_part; // this subselect is part of union bool optimized; // flag to avoid double optimization in EXPLAIN - JOIN(THD *thd_arg, List<Item> &fields, ulong select_options_arg, + JOIN(THD *thd_arg, List<Item> &fields_arg, ulong select_options_arg, select_result *result_arg) - :fields_list(fields) + :fields_list(fields_arg) { - init(thd_arg, fields, select_options_arg, result_arg); + init(thd_arg, fields_arg, select_options_arg, result_arg); } - void init(THD *thd_arg, List<Item> &fields, ulong select_options_arg, + void init(THD *thd_arg, List<Item> &fields_arg, ulong select_options_arg, select_result *result_arg) { join_tab= join_tab_save= 0; @@ -236,8 +248,8 @@ class JOIN :public Sql_alloc hidden_group_fields= 0; /*safety*/ buffer_result= test(select_options & OPTION_BUFFER_RESULT) && !test(select_options & OPTION_FOUND_ROWS); - all_fields= fields; - fields_list= fields; + all_fields= fields_arg; + fields_list= fields_arg; error= 0; select= 0; ref_pointer_array= items0= items1= items2= items3= 0; @@ -246,7 +258,7 @@ class JOIN :public Sql_alloc optimized= 0; cond_equal= 0; - fields_list= fields; + fields_list= fields_arg; bzero((char*) &keyuse,sizeof(keyuse)); tmp_table_param.copy_field=0; tmp_table_param.end_write_records= HA_POS_ERROR; @@ -256,7 +268,7 @@ class JOIN :public Sql_alloc int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num, COND *conds, uint og_num, ORDER *order, ORDER *group, Item *having, ORDER *proc_param, SELECT_LEX *select, - SELECT_LEX_UNIT *unit, bool tables_and_fields_initied); + SELECT_LEX_UNIT *unit); int optimize(); int reinit(); void exec(); |