Fixed LP bug #608744

The bug is a result of the following change by Monty:
  Revision Id: monty@askmonty.org-20100716073301-gstby2062nqd42qv
  Timestamp: Fri 2010-07-16 10:33:01 +0300
Where Monty changed the queues interface and implementation.

The fix adjusts the queue_remove call to the new interface.


mysql-test/r/subselect_partial_match.result:
  Added new file for tests related to MWL#89.
mysql-test/t/subselect_partial_match.test:
  Added new file for tests related to MWL#89.

mysql-test/r/subselect_partial_match.result

+drop table if exists t1, t2;
+#launchpad BUG#608744
+set @save_optimizer_switch=@@optimizer_switch;
+set @@optimizer_switch="materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=off";
+create table t1 (a1 char(1), a2 char(1));
+insert into t1 values (NULL, 'b');
+create table t2 (b1 char(1), b2 char(2));
+insert into t2 values ('a','b'), ('c', 'd');
+select * from t1 where (a1, a2) NOT IN (select b1, b2 from t2);
+a1	a2
+drop table t1,t2;
+set @@optimizer_switch=@save_optimizer_switch;

mysql-test/t/subselect_partial_match.test

+#
+# Tests for
+# MWL#68: Subquery optimization: Efficient NOT IN execution with NULLs
+#
+
+--disable_warnings
+drop table if exists t1, t2;
+--enable_warnings
+
+#
+--echo #launchpad BUG#608744
+#
+set @save_optimizer_switch=@@optimizer_switch;
+set @@optimizer_switch="materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=off";
+create table t1 (a1 char(1), a2 char(1));
+insert into t1 values (NULL, 'b');
+create table t2 (b1 char(1), b2 char(2));
+insert into t2 values ('a','b'), ('c', 'd');
+select * from t1 where (a1, a2) NOT IN (select b1, b2 from t2);
+drop table t1,t2;
+set @@optimizer_switch=@save_optimizer_switch;

sql/item_subselect.cc

@@ -4992,6 +4992,8 @@ bool subselect_rowid_merge_engine::partial_match()
 
   /* If there is a non-NULL key, it must be the first key in the keys array. */
   DBUG_ASSERT(!non_null_key || (non_null_key && merge_keys[0] == non_null_key));
+  /* The prioryty queue for keys must be empty. */
+  DBUG_ASSERT(!pq.elements);
 
   /* All data accesses during execution are via handler::ha_rnd_pos() */
   tmp_table->file->ha_rnd_init(0);
@@ -5056,7 +5058,7 @@ bool subselect_rowid_merge_engine::partial_match()
 
   DBUG_ASSERT(pq.elements);
 
-  min_key= (Ordered_key*) queue_remove(&pq, 0);
+  min_key= (Ordered_key*) queue_remove_top(&pq);
   min_row_num= min_key->current();
   bitmap_copy(&matching_keys, &null_only_columns);
   bitmap_set_bit(&matching_keys, min_key->get_keyid());
@@ -5076,7 +5078,7 @@ bool subselect_rowid_merge_engine::partial_match()
 
   while (TRUE)
   {
-    cur_key= (Ordered_key*) queue_remove(&pq, 0);
+    cur_key= (Ordered_key*) queue_remove_top(&pq);
     cur_row_num= cur_key->current();
 
     if (cur_row_num == min_row_num)
@@ -5115,6 +5117,7 @@ bool subselect_rowid_merge_engine::partial_match()
   DBUG_ASSERT(FALSE);
 
 end:
+  queue_remove_all(&pq);
   tmp_table->file->ha_rnd_end();
   return res;
 }