diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/opt_subselect.cc | 10 | ||||
| -rw-r--r-- | sql/sql_select.cc | 17 | ||||
| -rw-r--r-- | sql/sql_select.h | 19 |
3 files changed, 30 insertions, 16 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index 0819667e068..217966eb296 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -4138,6 +4138,16 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, { /* Looks like we'll be using join buffer */ first_table= join->const_tables; + /* + Make sure that possible sorting of rows from the head table + is not to be employed. + */ + if (join->get_sort_by_join_tab()) + { + join->simple_order= 0; + join->simple_group= 0; + join->need_tmp= join->test_if_need_tmp_table(); + } break; } } diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 7a86557901f..a4f3a1ee467 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1524,22 +1524,7 @@ JOIN::optimize() } } - /* - Check if we need to create a temporary table. - This has to be done if all tables are not already read (const tables) - and one of the following conditions holds: - - We are using DISTINCT (simple distinct's are already optimized away) - - We are using an ORDER BY or GROUP BY on fields not in the first table - - We are using different ORDER BY and GROUP BY orders - - The user wants us to buffer the result. - When the WITH ROLLUP modifier is present, we cannot skip temporary table - creation for the DISTINCT clause just because there are only const tables. - */ - need_tmp= ((const_tables != table_count && - ((select_distinct || !simple_order || !simple_group) || - (group_list && order) || - test(select_options & OPTION_BUFFER_RESULT))) || - (rollup.state != ROLLUP::STATE_NONE && select_distinct)); + need_tmp= test_if_need_tmp_table(); /* If the hint FORCE INDEX FOR ORDER BY/GROUP BY is used for the table diff --git a/sql/sql_select.h b/sql/sql_select.h index e24cab714fd..5a8dc846c92 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -1318,6 +1318,25 @@ public: return test(allowed_join_cache_types & JOIN_CACHE_HASHED_BIT) && max_allowed_join_cache_level > JOIN_CACHE_HASHED_BIT; } + /* + Check if we need to create a temporary table. + This has to be done if all tables are not already read (const tables) + and one of the following conditions holds: + - We are using DISTINCT (simple distinct's are already optimized away) + - We are using an ORDER BY or GROUP BY on fields not in the first table + - We are using different ORDER BY and GROUP BY orders + - The user wants us to buffer the result. + When the WITH ROLLUP modifier is present, we cannot skip temporary table + creation for the DISTINCT clause just because there are only const tables. + */ + bool test_if_need_tmp_table() + { + return ((const_tables != table_count && + ((select_distinct || !simple_order || !simple_group) || + (group_list && order) || + test(select_options & OPTION_BUFFER_RESULT))) || + (rollup.state != ROLLUP::STATE_NONE && select_distinct)); + } bool choose_subquery_plan(table_map join_tables); void get_partial_cost_and_fanout(int end_tab_idx, table_map filter_map, |