diff options
Diffstat (limited to 'sql/item_subselect.cc')
| -rw-r--r-- | sql/item_subselect.cc | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc index 7033d38c07b..de9b5dc8438 100644 --- a/sql/item_subselect.cc +++ b/sql/item_subselect.cc @@ -752,6 +752,7 @@ bool Item_subselect::exec() DBUG_ENTER("Item_subselect::exec"); DBUG_ASSERT(fixed); + DBUG_ASSERT(!eliminated); /* Do not execute subselect in case of a fatal error @@ -1313,6 +1314,16 @@ Item* Item_singlerow_subselect::expr_cache_insert_transformer(THD *tmp_thd, DBUG_ASSERT(thd == tmp_thd); + /* + Do not create subquery cache if the subquery was eliminated. + The optimizer may eliminate subquery items (see + eliminate_subselect_processor). However it does not update + all query's data structures, so the eliminated item may be + still reachable. + */ + if (eliminated) + DBUG_RETURN(this); + if (expr_cache) DBUG_RETURN(expr_cache); |