diff options
Diffstat (limited to 'sql/item_subselect.cc')
| -rw-r--r-- | sql/item_subselect.cc | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc index afc42dc08d5..9d6fe5ac5ab 100644 --- a/sql/item_subselect.cc +++ b/sql/item_subselect.cc @@ -1432,13 +1432,20 @@ void Item_exists_subselect::fix_length_and_dec() { DBUG_ENTER("Item_exists_subselect::fix_length_and_dec"); init_length_and_dec(); - /* - We need only 1 row to determine existence (i.e. any EXISTS that is not - an IN always requires LIMIT 1) - */ - thd->change_item_tree(&unit->global_parameters->select_limit, - new Item_int((int32) 1)); - DBUG_PRINT("info", ("Set limit to 1")); + // If limit is not set or it is constant more than 1 + if (!unit->global_parameters->select_limit || + (unit->global_parameters->select_limit->basic_const_item() && + unit->global_parameters->select_limit->val_int() > 1)) + { + /* + We need only 1 row to determine existence (i.e. any EXISTS that is not + an IN always requires LIMIT 1) + */ + thd->change_item_tree(&unit->global_parameters->select_limit, + new Item_int((int32) 1)); + unit->global_parameters->explicit_limit= 1; // we set the limit + DBUG_PRINT("info", ("Set limit to 1")); + } DBUG_VOID_RETURN; } |