MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

This patch does three things:
- It adds the possibility to force the execution of top-level [NOT] IN
  subquery predicates via the IN=>EXISTS transformation. This is done by
  setting both optimizer switches partial_match_rowid_merge and
  partial_match_table_scan to "off".
- It adjusts all test cases where the complete optimizer_switch is
  selected because now we have two more switches.
- For those test cases where the plan changes because of the new available
  strategies, we switch off both partial match strategies in order to
  force the "old" IN=>EXISTS strategy. This is done because most of these
  test cases specifically test bugs in this strategy.

sql/opt_subselect.cc:
  Adds the possibility to force the execution of top-level [NOT] IN
  subquery predicates via the IN=>EXISTS transformation. This is done by
  setting both optimizer switches partial_match_rowid_merge and
  partial_match_table_scan to "off".

1 files changed, 3 insertions, 0 deletions

diff --git a/mysql-test/include/mix1.inc b/mysql-test/include/mix1.inc
index 6dabe4864a9..4457ac3a618 100644
--- a/mysql-test/include/mix1.inc
+++ b/mysql-test/include/mix1.inc
@@ -1177,8 +1177,11 @@ DROP TABLE t1;
 
 create table t1 (a bit(1) not null,b int) engine=myisam;
 create table t2 (c int) engine=innodb;
+set @save_optimizer_switch=@@optimizer_switch;
+set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
 explain
 select b from t1 where a not in (select b from t1,t2 group by a) group by a;
+set optimizer_switch=@save_optimizer_switch;
 DROP TABLE t1,t2;
 
 --echo End of 5.0 tests