diff options
Diffstat (limited to 'sql/sql_lex.cc')
| -rw-r--r-- | sql/sql_lex.cc | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc index e863308159e..853b4d8cc1a 100644 --- a/sql/sql_lex.cc +++ b/sql/sql_lex.cc @@ -3170,7 +3170,41 @@ bool st_select_lex_unit::union_needs_tmp_table() global_parameters()->order_list.elements != 0 || thd->lex->sql_command == SQLCOM_INSERT_SELECT || thd->lex->sql_command == SQLCOM_REPLACE_SELECT; -} +} + + +/* + @brief + Check if the ORDER BY clause is redundant or empty + + @retval + TRUE order by is redundant or empty + FALSE OTHERWISE +*/ + +bool st_select_lex_unit::is_order_by_clause_redundant() +{ + if (global_parameters()->order_list.elements == 0) + return true; + if (is_union_op_inside_in_predicate()) + return true; + return false; +} + + +/* + @brief + Check if UNION is in side an IN/ALL/ANY subquery + + @retval + TRUE UNION inside in an IN/ALL/ANY subquery + FALSE Otherwise +*/ +bool st_select_lex_unit::is_union_op_inside_in_predicate() +{ + return is_union() && item && item->is_in_predicate(); +} + /** @brief Set the initial purpose of this TABLE_LIST object in the list of used @@ -4678,7 +4712,7 @@ int st_select_lex_unit::save_union_explain(Explain_query *output) eu->add_select(sl->select_number); eu->fake_select_type= "UNION RESULT"; - eu->using_filesort= MY_TEST(global_parameters()->order_list.first); + eu->using_filesort= MY_TEST(!is_order_by_clause_redundant()); eu->using_tmp= union_needs_tmp_table(); // Save the UNION node |