Problem was that for cases like:

SELECT ... WHERE XX IN (SELECT YY)
this was transformed to something like:
SELECT ... WHERE IF_EXISTS(SELECT ... HAVING XX=YY)

The bug was that for normal execution XX was fixed in the original outer SELECT context while in PS it was fixed in the sub query context and this confused the optimizer.

Fixed by ensuring that XX is always fixed in the outer context.

1 files changed, 7 insertions, 5 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 5ed7a67da61..e542b08f911 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -4904,6 +4904,8 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
   KEY_FIELD *key_fields, *end, *field;
   uint sz;
   uint m= max(select_lex->max_equal_elems,1);
+  DBUG_ENTER("update_ref_and_keys");
+  DBUG_PRINT("enter", ("normal_tables: %llx", normal_tables));
 
   SELECT_LEX *sel=thd->lex->current_select; 
   sel->cond_count= 0;
@@ -4950,7 +4952,7 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
   sz= max(sizeof(KEY_FIELD),sizeof(SARGABLE_PARAM))*
     ((sel->cond_count*2 + sel->between_count)*m+1);
   if (!(key_fields=(KEY_FIELD*)	thd->alloc(sz)))
-    return TRUE; /* purecov: inspected */
+    DBUG_RETURN(TRUE); /* purecov: inspected */
   and_level= 0;
   field= end= key_fields;
   *sargables= (SARGABLE_PARAM *) key_fields + 
@@ -4959,7 +4961,7 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
   (*sargables)[0].field= 0; 
 
   if (my_init_dynamic_array(keyuse,sizeof(KEYUSE),20,64))
-    return TRUE;
+    DBUG_RETURN(TRUE);
 
   if (cond)
   {
@@ -5009,16 +5011,16 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
   for ( ; field != end ; field++)
   {
     if (add_key_part(keyuse,field))
-      return TRUE;
+      DBUG_RETURN(TRUE);
   }
 
   if (select_lex->ftfunc_list->elements)
   {
     if (add_ft_keys(keyuse,join_tab,cond,normal_tables))
-      return TRUE;
+      DBUG_RETURN(TRUE);
   }
 
-  return FALSE;
+  DBUG_RETURN(FALSE);
 }