Change the default @@optimizer_switch setting from

  semijoin=on,firstmatch=on,loosescan=on
to
  semijoin=off,firstmatch=off,loosescan=off
Adjust the testcases:
- Modify subselect*.test and join_cache.test so that all tests
  use the same execution paths as before (i.e. optimizations that
  are being tested are enabled)
- Let all other test files run with the new default settings (i.e.
  with new optimizations disabled)
- Copy subquery testcases from these files into t/subselect_extra.test
  which will run them with new optimizations enabled.

38 files changed, 263 insertions, 159 deletions

diff --git a/mysql-test/r/explain.result b/mysql-test/r/explain.result
index d18af9fd4e1..e123989567d 100644
--- a/mysql-test/r/explain.result
+++ b/mysql-test/r/explain.result
@@ -199,16 +199,16 @@ insert into t2 values ('2001-01-01 1:1:1'), ('2001-01-01 1:1:1');
 flush tables;
 EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where
 flush tables;
 SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
 dt
 flush tables;
 EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where
 flush tables;
 SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
 dt
diff --git a/mysql-test/r/group_by.result b/mysql-test/r/group_by.result
index 33376b22bc6..6bae35e27a2 100644
--- a/mysql-test/r/group_by.result
+++ b/mysql-test/r/group_by.result
@@ -1542,8 +1542,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT 1 FROM t1 WHERE a IN
 (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	PRIMARY,i2	PRIMARY	4	NULL	144	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	144	Using where; FirstMatch(t1)
+1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	144	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	Using where
 CREATE TABLE t2 (a INT, b INT, KEY(a));
 INSERT INTO t2 VALUES (1, 1), (2, 2), (3,3), (4,4);
 EXPLAIN SELECT a, SUM(b) FROM t2 GROUP BY a LIMIT 2;
@@ -1555,8 +1555,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT 1 FROM t2 WHERE a IN
 (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	index	a	a	5	NULL	4	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	144	Using where; FirstMatch(t2)
+1	PRIMARY	t2	index	NULL	a	5	NULL	4	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	Using where
 SHOW VARIABLES LIKE 'old';
 Variable_name	Value
 old	OFF
diff --git a/mysql-test/r/group_min_max.result b/mysql-test/r/group_min_max.result
index 0b3df689089..c33e632ffbb 100644
--- a/mysql-test/r/group_min_max.result
+++ b/mysql-test/r/group_min_max.result
@@ -1432,7 +1432,7 @@ group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	range	NULL	idx_t1_1	147	NULL	17	Using where; Using index for group-by
 2	DEPENDENT SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	164	Using where; Using index
-2	DEPENDENT SUBQUERY	t3	index	NULL	idx_t3_1	10	NULL	192	Using where; Using index; FirstMatch(t2)
+3	DEPENDENT SUBQUERY	t3	index	NULL	idx_t3_1	10	NULL	192	Using where; Using index
 select a1,a2,b,c,min(c), max(c) from t1
 where exists ( select * from t2
 where t2.c in (select c from t3 where t3.c > t1.b) and
@@ -1489,7 +1489,7 @@ group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	idx_t1_1	163	NULL	128	Using where; Using index
 2	DEPENDENT SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	164	Using where; Using index
-2	DEPENDENT SUBQUERY	t3	index	NULL	idx_t3_1	10	NULL	192	Using where; Using index; FirstMatch(t2)
+3	DEPENDENT SUBQUERY	t3	index	NULL	idx_t3_1	10	NULL	192	Using where; Using index
 select a1,a2,b,c,min(c), max(c) from t1
 where exists ( select * from t2
 where t2.c in (select c from t3 where t3.c > t1.c) and
diff --git a/mysql-test/r/join_cache.result b/mysql-test/r/join_cache.result
index 58a40bae4da..7b890e4d4aa 100644
--- a/mysql-test/r/join_cache.result
+++ b/mysql-test/r/join_cache.result
@@ -1,6 +1,7 @@
 DROP TABLE IF EXISTS t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11;
 DROP DATABASE IF EXISTS world;
 set @save_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @@optimizer_switch='semijoin_with_cache=on';
 set @@optimizer_switch='outer_join_with_cache=on';
 set names utf8;
diff --git a/mysql-test/r/optimizer_switch.result b/mysql-test/r/optimizer_switch.result
index 937b4dfeffa..ff077ed9fc9 100644
--- a/mysql-test/r/optimizer_switch.result
+++ b/mysql-test/r/optimizer_switch.result
@@ -4,19 +4,19 @@
 #
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='index_merge=off,index_merge_union=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='index_merge_union=on';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,index_merge_sort_union=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch=4;
 ERROR 42000: Variable 'optimizer_switch' can't be set to the value of '4'
 set optimizer_switch=NULL;
@@ -43,60 +43,60 @@ set optimizer_switch=default;
 set optimizer_switch='index_merge=off,index_merge_union=off,default';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch=default;
 select @@global.optimizer_switch;
 @@global.optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set @@global.optimizer_switch=default;
 select @@global.optimizer_switch;
 @@global.optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 #
 # Check index_merge's @@optimizer_switch flags
 #
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 
 BUG#37120 optimizer_switch allowable values not according to specification
 
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,materialization=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,semijoin=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,loosescan=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=off,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,semijoin=off,materialization=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,materialization=off,semijoin=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,semijoin=off,materialization=off,loosescan=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,semijoin=off,loosescan=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch='default,materialization=off,loosescan=off';
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=off,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
 set optimizer_switch=default;
 select @@optimizer_switch;
 @@optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 63f2775b094..56c2c915cb0 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -1,7 +1,8 @@
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
 drop view if exists v2;
-set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @subselect_tmp=@@optimizer_switch;
+set @@optimizer_switch=ifnull(@optimizer_switch_for_subselect_test,
+"semijoin=on,firstmatch=on,loosescan=on,partial_match_rowid_merge=off,partial_match_table_scan=off");
 select (select 2);
 (select 2)
 2
@@ -4803,7 +4804,6 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
-set @@optimizer_switch=@save_optimizer_switch;
 #
 # Bug #49512 : subquery with aggregate function crash 
 #   subselect_single_select_engine::exec()
@@ -5127,3 +5127,4 @@ ON t2.f10 = t3.f10
 f1
 DROP TABLE t1,t2,t3;
 End of 5.3 tests
+set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/r/subselect2.result b/mysql-test/r/subselect2.result
index 16273711a49..4fd86f10530 100644
--- a/mysql-test/r/subselect2.result
+++ b/mysql-test/r/subselect2.result
@@ -1,4 +1,6 @@
 drop table if exists t1, t2, t3, t4;
+set @subselect2_test_tmp=@@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on';
 CREATE TABLE t1
 (
 DOCID VARCHAR(32)BINARY NOT NULL
@@ -144,3 +146,4 @@ and t2.a='1' AND t1.a=t3.b) > 0;
 a
 2
 DROP TABLE t1,t2,t3;
+set optimizer_switch=@subselect2_test_tmp;
diff --git a/mysql-test/r/subselect3.result b/mysql-test/r/subselect3.result
index e88461173df..3d5091bf36b 100644
--- a/mysql-test/r/subselect3.result
+++ b/mysql-test/r/subselect3.result
@@ -1,5 +1,6 @@
 drop table if exists t0, t1, t2, t3, t4, t5, t11, t12, t21, t22;
-set @save_optimizer_switch=@@optimizer_switch;
+set @subselect3_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 create table t1 (oref int, grp int, ie int) ;
 insert into t1 (oref, grp, ie) values
 (1, 1, 1),
@@ -698,7 +699,6 @@ a	MAX(b)	test
 2	3	h
 3	4	i
 DROP TABLE t1, t2;
-set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
 CREATE TABLE t1 (a int);
 CREATE TABLE t2 (b int, PRIMARY KEY(b));
@@ -1084,7 +1084,8 @@ a
 17
 18
 19
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch='materialization=off';
 explain select * from t1 where 2 in (select a from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	11	Using where; FirstMatch
@@ -1399,7 +1400,7 @@ drop table t1,t2,t3;
 #
 # BUG#47367 Crash in Name_resolution_context::process_error
 #
-SET SESSION optimizer_switch = 'default,semijoin=off';
+SET SESSION optimizer_switch = 'semijoin=off';
 CREATE TABLE t1 (f1 INTEGER);
 CREATE TABLE t2 LIKE t1;
 CREATE PROCEDURE p1 () BEGIN SELECT f1 FROM t1 WHERE f1 IN (SELECT f1 FROM t2); END|
@@ -1421,4 +1422,4 @@ CALL p1;
 ERROR 42S22: Unknown column 'f1' in 'where clause'
 DROP PROCEDURE p1;
 DROP TABLE t1, t2;
-set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch=@subselect3_tmp;
diff --git a/mysql-test/r/subselect3_jcl6.result b/mysql-test/r/subselect3_jcl6.result
index e254fad2300..2225242c663 100644
--- a/mysql-test/r/subselect3_jcl6.result
+++ b/mysql-test/r/subselect3_jcl6.result
@@ -6,7 +6,8 @@ show variables like 'join_cache_level';
 Variable_name	Value
 join_cache_level	6
 drop table if exists t0, t1, t2, t3, t4, t5, t11, t12, t21, t22;
-set @save_optimizer_switch=@@optimizer_switch;
+set @subselect3_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 create table t1 (oref int, grp int, ie int) ;
 insert into t1 (oref, grp, ie) values
 (1, 1, 1),
@@ -705,7 +706,6 @@ a	MAX(b)	test
 2	3	h
 3	4	i
 DROP TABLE t1, t2;
-set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
 CREATE TABLE t1 (a int);
 CREATE TABLE t2 (b int, PRIMARY KEY(b));
@@ -1091,7 +1091,8 @@ a
 17
 18
 19
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch='materialization=off';
 explain select * from t1 where 2 in (select a from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	11	Using where; FirstMatch
@@ -1406,7 +1407,7 @@ drop table t1,t2,t3;
 #
 # BUG#47367 Crash in Name_resolution_context::process_error
 #
-SET SESSION optimizer_switch = 'default,semijoin=off';
+SET SESSION optimizer_switch = 'semijoin=off';
 CREATE TABLE t1 (f1 INTEGER);
 CREATE TABLE t2 LIKE t1;
 CREATE PROCEDURE p1 () BEGIN SELECT f1 FROM t1 WHERE f1 IN (SELECT f1 FROM t2); END|
@@ -1428,7 +1429,7 @@ CALL p1;
 ERROR 42S22: Unknown column 'f1' in 'where clause'
 DROP PROCEDURE p1;
 DROP TABLE t1, t2;
-set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch=@subselect3_tmp;
 set join_cache_level=default;
 show variables like 'join_cache_level';
 Variable_name	Value
diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result
index 4cdc75a29f8..de4f386f831 100644
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -1,4 +1,6 @@
 drop table if exists t1,t2,t3,t4,t5,t6;
+set @subselect4_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 #
 # Bug #46791: Assertion failed:(table->key_read==0),function unknown
 #    function,file sql_base.cc
@@ -1736,3 +1738,4 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
 3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
 drop table t1, t2, t3;
+set optimizer_switch=@subselect4_tmp;
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 889293d2908..409c14c3d57 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -1,4 +1,7 @@
-set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
+set @subselect_mat_test_optimizer_switch_value='materialization=on,in_to_exists=off,semijoin=off';
+set @subselect_sj_mat_tmp= @@optimizer_switch;
+set optimizer_switch=ifnull(@subselect_mat_test_optimizer_switch_value, 'semijoin=on,firstmatch=on,loosescan=on');
+set @optimizer_switch_local_default= @@optimizer_switch;
 drop table if exists t1, t2, t3, t1i, t2i, t3i;
 drop table if exists columns;
 drop table if exists t1_16, t2_16, t3_16;
@@ -180,28 +183,34 @@ a1	a2
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2i limit 1,1);
 ERROR 42000: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
 a1	a2
 1 - 01	2 - 01
@@ -1145,28 +1154,31 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 min(a1)
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 min(a1)
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 # with MariaDB and MWL#90, this particular case is solved:
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
-NULL
 # but when we go around MWL#90 code, the problem still shows up:
 explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -1199,7 +1211,8 @@ CREATE TABLE t2 LIKE t1;
 INSERT INTO t2 VALUES (1, 1.789);
 INSERT INTO t2 VALUES (13, 1.454);
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
@@ -1222,7 +1235,8 @@ INSERT INTO t1 VALUES (1,'o','ffff','ffff','ffoo'),(2,'f','ffff','ffff','ffff');
 CREATE TABLE t2 LIKE t1;
 INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii'),(2,'f','ffff','ffff','ffff');
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
@@ -1320,6 +1334,8 @@ select left(a1,7), left(a2,7) from t1_1024 where (a1,3) in (select substring(b1,
 left(a1,7)	left(a2,7)
 1 - 01x	2 - 01x
 drop table t1_1024, t2_1024;
+set optimizer_switch=@subselect_sj_mat_tmp;
+set @subselect_mat_test_optimizer_switch_value=null;
 set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
 create table t0 (a int);
 insert into t0 values (0),(1),(2);
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index eee9db65ae9..dabffd16d93 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -4,8 +4,9 @@ select @@optimizer_switch like '%materialization=on%';
 set optimizer_switch='materialization=off';
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
 drop view if exists v2;
-set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @subselect_tmp=@@optimizer_switch;
+set @@optimizer_switch=ifnull(@optimizer_switch_for_subselect_test,
+"semijoin=on,firstmatch=on,loosescan=on,partial_match_rowid_merge=off,partial_match_table_scan=off");
 select (select 2);
 (select 2)
 2
@@ -4807,7 +4808,6 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
-set @@optimizer_switch=@save_optimizer_switch;
 #
 # Bug #49512 : subquery with aggregate function crash 
 #   subselect_single_select_engine::exec()
@@ -5131,6 +5131,7 @@ ON t2.f10 = t3.f10
 f1
 DROP TABLE t1,t2,t3;
 End of 5.3 tests
+set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
 select @@optimizer_switch like '%materialization=on%';
 @@optimizer_switch like '%materialization=on%'
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 493ab9dba59..2e643027ce6 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -1,8 +1,9 @@
-set optimizer_switch='materialization=off,semijoin=off';
+set @optimizer_switch_for_subselect_test='materialization=off,semijoin=off';
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
 drop view if exists v2;
-set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @subselect_tmp=@@optimizer_switch;
+set @@optimizer_switch=ifnull(@optimizer_switch_for_subselect_test,
+"semijoin=on,firstmatch=on,loosescan=on,partial_match_rowid_merge=off,partial_match_table_scan=off");
 select (select 2);
 (select 2)
 2
@@ -4804,7 +4805,6 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
-set @@optimizer_switch=@save_optimizer_switch;
 #
 # Bug #49512 : subquery with aggregate function crash 
 #   subselect_single_select_engine::exec()
@@ -5128,4 +5128,5 @@ ON t2.f10 = t3.f10
 f1
 DROP TABLE t1,t2,t3;
 End of 5.3 tests
-set optimizer_switch=default;
+set optimizer_switch=@subselect_tmp;
+set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index 434bcd33a21..ebe85ca4670 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -1,8 +1,9 @@
-set optimizer_switch='semijoin=off';
+set @optimizer_switch_for_subselect_test='semijoin=off';
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
 drop view if exists v2;
-set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @subselect_tmp=@@optimizer_switch;
+set @@optimizer_switch=ifnull(@optimizer_switch_for_subselect_test,
+"semijoin=on,firstmatch=on,loosescan=on,partial_match_rowid_merge=off,partial_match_table_scan=off");
 select (select 2);
 (select 2)
 2
@@ -4804,7 +4805,6 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
-set @@optimizer_switch=@save_optimizer_switch;
 #
 # Bug #49512 : subquery with aggregate function crash 
 #   subselect_single_select_engine::exec()
@@ -5128,4 +5128,5 @@ ON t2.f10 = t3.f10
 f1
 DROP TABLE t1,t2,t3;
 End of 5.3 tests
-set optimizer_switch=default;
+set optimizer_switch=@subselect_tmp;
+set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_sj.result b/mysql-test/r/subselect_sj.result
index 316f8c7e815..23e216a282a 100644
--- a/mysql-test/r/subselect_sj.result
+++ b/mysql-test/r/subselect_sj.result
@@ -1,6 +1,8 @@
 drop table if exists t0, t1, t2, t3, t4, t10, t11, t12;
 drop view if exists v1, v2;
 drop procedure if exists p1;
+set @subselect_sj_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @save_optimizer_switch=@@optimizer_switch;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -1536,4 +1538,4 @@ AND t1.f1 = t2.f1 ;
 f1	f1
 DROP TABLE t1, t2;
 set optimizer_switch=@save_802965;
-set @@optimizer_switch=@save_optimizer_switch;
+set optimizer_switch=@subselect_sj_tmp;
diff --git a/mysql-test/r/subselect_sj2.result b/mysql-test/r/subselect_sj2.result
index 45dd12a6b77..7a770abb474 100644
--- a/mysql-test/r/subselect_sj2.result
+++ b/mysql-test/r/subselect_sj2.result
@@ -1,3 +1,5 @@
+set @subselect_sj2_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 drop table if exists t0, t1, t2, t3;
 drop view if exists v1;
 create table t0 (a int);
@@ -744,3 +746,4 @@ LEFT JOIN t2 AS SQ4_alias3 ON SQ4_alias3.f10
 GROUP BY field2;
 field2
 drop table t1, t2, t3;
+set optimizer_switch=@subselect_sj2_tmp;
diff --git a/mysql-test/r/subselect_sj2_jcl6.result b/mysql-test/r/subselect_sj2_jcl6.result
index 45cce630a22..5292e70e100 100644
--- a/mysql-test/r/subselect_sj2_jcl6.result
+++ b/mysql-test/r/subselect_sj2_jcl6.result
@@ -5,6 +5,8 @@ set join_cache_level=6;
 show variables like 'join_cache_level';
 Variable_name	Value
 join_cache_level	6
+set @subselect_sj2_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 drop table if exists t0, t1, t2, t3;
 drop view if exists v1;
 create table t0 (a int);
@@ -753,6 +755,7 @@ LEFT JOIN t2 AS SQ4_alias3 ON SQ4_alias3.f10
 GROUP BY field2;
 field2
 drop table t1, t2, t3;
+set optimizer_switch=@subselect_sj2_tmp;
 set join_cache_level=default;
 show variables like 'join_cache_level';
 Variable_name	Value
diff --git a/mysql-test/r/subselect_sj2_mat.result b/mysql-test/r/subselect_sj2_mat.result
index 0919e8701e2..83507909cf1 100644
--- a/mysql-test/r/subselect_sj2_mat.result
+++ b/mysql-test/r/subselect_sj2_mat.result
@@ -1,4 +1,6 @@
 set optimizer_switch='materialization=on';
+set @subselect_sj2_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 drop table if exists t0, t1, t2, t3;
 drop view if exists v1;
 create table t0 (a int);
@@ -755,6 +757,7 @@ LEFT JOIN t2 AS SQ4_alias3 ON SQ4_alias3.f10
 GROUP BY field2;
 field2
 drop table t1, t2, t3;
+set optimizer_switch=@subselect_sj2_tmp;
 set optimizer_switch=default;
 select @@optimizer_switch like '%materialization=on%';
 @@optimizer_switch like '%materialization=on%'
diff --git a/mysql-test/r/subselect_sj_jcl6.result b/mysql-test/r/subselect_sj_jcl6.result
index 282142496d1..684d3d805da 100644
--- a/mysql-test/r/subselect_sj_jcl6.result
+++ b/mysql-test/r/subselect_sj_jcl6.result
@@ -1,4 +1,5 @@
 set @save_optimizer_switch_jcl6=@@optimizer_switch;
+set @@optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @@optimizer_switch='semijoin_with_cache=on';
 set @@optimizer_switch='outer_join_with_cache=on';
 set @@optimizer_switch='join_cache_hashed=off';
@@ -9,6 +10,8 @@ join_cache_level	6
 drop table if exists t0, t1, t2, t3, t4, t10, t11, t12;
 drop view if exists v1, v2;
 drop procedure if exists p1;
+set @subselect_sj_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @save_optimizer_switch=@@optimizer_switch;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -1544,7 +1547,7 @@ AND t1.f1 = t2.f1 ;
 f1	f1
 DROP TABLE t1, t2;
 set optimizer_switch=@save_802965;
-set @@optimizer_switch=@save_optimizer_switch;
+set optimizer_switch=@subselect_sj_tmp;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off
 #
diff --git a/mysql-test/r/subselect_sj_mat.result b/mysql-test/r/subselect_sj_mat.result
index a3b19b38867..31afe6fed1c 100644
--- a/mysql-test/r/subselect_sj_mat.result
+++ b/mysql-test/r/subselect_sj_mat.result
@@ -1,3 +1,6 @@
+set @subselect_sj_mat_tmp= @@optimizer_switch;
+set optimizer_switch=ifnull(@subselect_mat_test_optimizer_switch_value, 'semijoin=on,firstmatch=on,loosescan=on');
+set @optimizer_switch_local_default= @@optimizer_switch;
 drop table if exists t1, t2, t3, t1i, t2i, t3i;
 drop table if exists columns;
 drop table if exists t1_16, t2_16, t3_16;
@@ -190,28 +193,34 @@ a1	a2
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2i limit 1,1);
 ERROR 42000: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
 a1	a2
 1 - 01	2 - 01
@@ -1182,21 +1191,24 @@ select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 min(a1)
 NULL
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 min(a1)
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
 2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 # with MariaDB and MWL#90, this particular case is solved:
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -1237,7 +1249,8 @@ CREATE TABLE t2 LIKE t1;
 INSERT INTO t2 VALUES (1, 1.789);
 INSERT INTO t2 VALUES (13, 1.454);
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
@@ -1260,7 +1273,8 @@ INSERT INTO t1 VALUES (1,'o','ffff','ffff','ffoo'),(2,'f','ffff','ffff','ffff');
 CREATE TABLE t2 LIKE t1;
 INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii'),(2,'f','ffff','ffff','ffff');
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
@@ -1358,3 +1372,4 @@ select left(a1,7), left(a2,7) from t1_1024 where (a1,3) in (select substring(b1,
 left(a1,7)	left(a2,7)
 1 - 01x	2 - 01x
 drop table t1_1024, t2_1024;
+set optimizer_switch=@subselect_sj_mat_tmp;
diff --git a/mysql-test/r/subselect_sj_nonmerged.result b/mysql-test/r/subselect_sj_nonmerged.result
index e0d1140da74..c1d733ad622 100644
--- a/mysql-test/r/subselect_sj_nonmerged.result
+++ b/mysql-test/r/subselect_sj_nonmerged.result
@@ -1,6 +1,6 @@
 drop table if exists t0, t1, t2, t3, t4;
 set @save_optimizer_switch=@@optimizer_switch;
-set optimizer_switch='materialization=on';
+set optimizer_switch='semijoin=on,materialization=on';
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
 create table t1 as select * from t0;
diff --git a/mysql-test/r/type_datetime.result b/mysql-test/r/type_datetime.result
index 092be494302..4dd2fc320ed 100644
--- a/mysql-test/r/type_datetime.result
+++ b/mysql-test/r/type_datetime.result
@@ -514,10 +514,11 @@ explain extended
 select * from t1
 where id in (select id from t1 as x1 where (t1.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1276	Field or reference 'test.t1.cur_date' of SELECT #2 was resolved in SELECT #1
-Note	1003	select 1 AS `id`,'2007-04-25 18:30:22' AS `cur_date` from `test`.`t1` semi join (`test`.`t1` `x1`) where (('2007-04-25 18:30:22' = 0))
+Note	1003	select 1 AS `id`,'2007-04-25 18:30:22' AS `cur_date` from `test`.`t1` where <expr_cache><1,'2007-04-25 18:30:22'>(<in_optimizer>(1,<exists>(select `test`.`x1`.`id` from `test`.`t1` `x1` where 0)))
 select * from t1
 where id in (select id from t1 as x1 where (t1.cur_date is null));
 id	cur_date
@@ -525,10 +526,11 @@ explain extended
 select * from t2
 where id in (select id from t2 as x1 where (t2.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1276	Field or reference 'test.t2.cur_date' of SELECT #2 was resolved in SELECT #1
-Note	1003	select 1 AS `id`,'2007-04-25' AS `cur_date` from `test`.`t2` semi join (`test`.`t2` `x1`) where (('2007-04-25' = 0))
+Note	1003	select 1 AS `id`,'2007-04-25' AS `cur_date` from `test`.`t2` where <expr_cache><1,'2007-04-25'>(<in_optimizer>(1,<exists>(select `test`.`x1`.`id` from `test`.`t2` `x1` where 0)))
 select * from t2
 where id in (select id from t2 as x1 where (t2.cur_date is null));
 id	cur_date
@@ -538,11 +540,11 @@ explain extended
 select * from t1
 where id in (select id from t1 as x1 where (t1.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary
-1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	DEPENDENT SUBQUERY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'test.t1.cur_date' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`cur_date` AS `cur_date` from `test`.`t1` semi join (`test`.`t1` `x1`) where ((`test`.`x1`.`id` = `test`.`t1`.`id`) and (`test`.`t1`.`cur_date` = 0))
+Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`cur_date` AS `cur_date` from `test`.`t1` where <expr_cache><`test`.`t1`.`id`,`test`.`t1`.`cur_date`>(<in_optimizer>(`test`.`t1`.`id`,<exists>(select `test`.`x1`.`id` from `test`.`t1` `x1` where ((`test`.`t1`.`cur_date` = 0) and (<cache>(`test`.`t1`.`id`) = `test`.`x1`.`id`)))))
 select * from t1
 where id in (select id from t1 as x1 where (t1.cur_date is null));
 id	cur_date
@@ -550,11 +552,11 @@ explain extended
 select * from t2
 where id in (select id from t2 as x1 where (t2.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary
-1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	DEPENDENT SUBQUERY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'test.t2.cur_date' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t2`.`id` AS `id`,`test`.`t2`.`cur_date` AS `cur_date` from `test`.`t2` semi join (`test`.`t2` `x1`) where ((`test`.`x1`.`id` = `test`.`t2`.`id`) and (`test`.`t2`.`cur_date` = 0))
+Note	1003	select `test`.`t2`.`id` AS `id`,`test`.`t2`.`cur_date` AS `cur_date` from `test`.`t2` where <expr_cache><`test`.`t2`.`id`,`test`.`t2`.`cur_date`>(<in_optimizer>(`test`.`t2`.`id`,<exists>(select `test`.`x1`.`id` from `test`.`t2` `x1` where ((`test`.`t2`.`cur_date` = 0) and (<cache>(`test`.`t2`.`id`) = `test`.`x1`.`id`)))))
 select * from t2
 where id in (select id from t2 as x1 where (t2.cur_date is null));
 id	cur_date
diff --git a/mysql-test/suite/pbxt/r/subselect.result b/mysql-test/suite/pbxt/r/subselect.result
index e183cf389c0..bcacfe3765e 100644
--- a/mysql-test/suite/pbxt/r/subselect.result
+++ b/mysql-test/suite/pbxt/r/subselect.result
@@ -1294,31 +1294,31 @@ a
 4
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY))))
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
 2
 4
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
 3
 explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	eq_ref	PRIMARY	PRIMARY	4	func	1	100.00	Using where
+2	DEPENDENT SUBQUERY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(select `test`.`t1`.`a` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))))
 drop table t1, t2, t3;
 create table t1 (a int, b int, index a (a,b));
 create table t2 (a int, index a (a));
@@ -1333,31 +1333,31 @@ a
 4
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
-1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using index; FirstMatch(t2)
+1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where (`test`.`t1`.`a` = `test`.`t2`.`a`)
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a))))
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
 2
 4
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
-1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index; FirstMatch(t2)
+1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
 3
 explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index; Start temporary
-1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using index
-1	PRIMARY	t3	index	a	a	5	NULL	3	100.00	Using where; Using index; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	ref	a	a	5	func	1	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t3	ref	a	a	5	test.t1.b	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1` join `test`.`t3`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(select `test`.`t1`.`a` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))))
 insert into t1 values (3,31);
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
@@ -1370,10 +1370,10 @@ a
 4
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
-1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index; FirstMatch(t2)
+1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <expr_cache><`test`.`t2`.`a`>(<in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))))
 drop table t1, t2, t3;
 create table t1 (a int, b int);
 create table t2 (a int, b int);
@@ -2827,10 +2827,10 @@ Warnings:
 Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`two`,`test`.`t1`.`one`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
 explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; FirstMatch(t1)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`two` = `test`.`t1`.`two`) and (`test`.`t2`.`one` = `test`.`t1`.`one`) and (`test`.`t2`.`flag` = 'N'))
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` where <expr_cache><`test`.`t1`.`two`,`test`.`t1`.`one`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = 'N') and (<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) and (<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`)))))
 explain extended SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = '0' group by one,two) as 'test' from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
@@ -4217,8 +4217,8 @@ CREATE INDEX I1 ON t1 (a);
 CREATE INDEX I2 ON t1 (b);
 EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	I1	I1	2	NULL	2	Using where; Using index; LooseScan
-1	PRIMARY	t1	ref	I2	I2	13	test.t1.a	1	Using where
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	index_subquery	I1	I1	2	func	1	Using index; Using where
 SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
 a	b
 CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10));
@@ -4227,15 +4227,15 @@ CREATE INDEX I1 ON t2 (a);
 CREATE INDEX I2 ON t2 (b);
 EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	index	I1	I1	4	NULL	2	Using where; Using index; LooseScan
-1	PRIMARY	t2	ref	I2	I2	13	test.t2.a	1	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	index_subquery	I1	I1	4	func	1	Using index; Using where
 SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
 a	b
 EXPLAIN
 SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	I1	I1	2	NULL	2	Using where; Using index; LooseScan
-1	PRIMARY	t1	ref	I2	I2	13	test.t1.a	1	Using where
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	index_subquery	I1	I1	2	func	1	Using index; Using where
 SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
 a	b
 DROP TABLE t1,t2;
diff --git a/mysql-test/suite/vcol/r/vcol_select_innodb.result b/mysql-test/suite/vcol/r/vcol_select_innodb.result
index 129022dd7cc..89a79b1acf8 100644
--- a/mysql-test/suite/vcol/r/vcol_select_innodb.result
+++ b/mysql-test/suite/vcol/r/vcol_select_innodb.result
@@ -63,8 +63,8 @@ a	b	c
 3	-3	-3
 explain select * from t1 where b in (select c from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	index	c	c	5	NULL	3	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	DEPENDENT SUBQUERY	t3	index_subquery	c	c	5	func	1	Using index
 # select_type=PRIMARY, type=range,ref
 select * from t1 where c in (select c from t3 where c between -2 and -1);
 a	b	c
@@ -73,8 +73,8 @@ a	b	c
 1	-1	-1
 explain select * from t1 where c in (select c from t3 where c between -2 and -1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	index	c	c	5	NULL	3	Using where; Using index
-1	PRIMARY	t1	ref	c	c	5	test.t3.c	1	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	DEPENDENT SUBQUERY	t3	index_subquery	c	c	5	func	1	Using index; Using where
 # select_type=UNION, type=system
 # select_type=UNION RESULT, type=<union1,2>
 select * from t1 union select * from t2;
diff --git a/mysql-test/suite/vcol/r/vcol_select_myisam.result b/mysql-test/suite/vcol/r/vcol_select_myisam.result
index 43ec4e90e88..bec56f841dc 100644
--- a/mysql-test/suite/vcol/r/vcol_select_myisam.result
+++ b/mysql-test/suite/vcol/r/vcol_select_myisam.result
@@ -63,8 +63,8 @@ a	b	c
 3	-3	-3
 explain select * from t1 where b in (select c from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	index	c	c	5	NULL	3	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	DEPENDENT SUBQUERY	t3	index_subquery	c	c	5	func	2	Using index
 # select_type=PRIMARY, type=range,ref
 select * from t1 where c in (select c from t3 where c between -2 and -1);
 a	b	c
@@ -73,8 +73,8 @@ a	b	c
 1	-1	-1
 explain select * from t1 where c in (select c from t3 where c between -2 and -1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	index	c	c	5	NULL	3	Using where; Using index
-1	PRIMARY	t1	ref	c	c	5	test.t3.c	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	DEPENDENT SUBQUERY	t3	index_subquery	c	c	5	func	2	Using index; Using where
 # select_type=UNION, type=system
 # select_type=UNION RESULT, type=<union1,2>
 select * from t1 union select * from t2;
diff --git a/mysql-test/t/join_cache.test b/mysql-test/t/join_cache.test
index 1d5addeb808..aac55dcb27b 100644
--- a/mysql-test/t/join_cache.test
+++ b/mysql-test/t/join_cache.test
@@ -4,6 +4,7 @@ DROP DATABASE IF EXISTS world;
 --enable_warnings
 
 set @save_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @@optimizer_switch='semijoin_with_cache=on';
 set @@optimizer_switch='outer_join_with_cache=on';
 
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index 3f843cdf534..d6aa73e8010 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -12,8 +12,9 @@ drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
 drop view if exists v2;
 --enable_warnings
 
-set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @subselect_tmp=@@optimizer_switch;
+set @@optimizer_switch=ifnull(@optimizer_switch_for_subselect_test,
+                              "semijoin=on,firstmatch=on,loosescan=on,partial_match_rowid_merge=off,partial_match_table_scan=off");
 
 select (select 2);
 explain extended select (select 2);
@@ -4066,7 +4067,7 @@ SELECT 1 FROM t1 GROUP BY
   (SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
 DROP TABLE t1;
 
-set @@optimizer_switch=@save_optimizer_switch;
+#Seems to be not needed here: set @@optimizer_switch=@subselect_tmp;
 --echo #
 --echo # Bug #49512 : subquery with aggregate function crash 
 --echo #   subselect_single_select_engine::exec()
@@ -4402,3 +4403,4 @@ WHERE
 DROP TABLE t1,t2,t3;
 
 --echo End of 5.3 tests
+set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/t/subselect2.test b/mysql-test/t/subselect2.test
index 162bdd0d90a..b6b1388be1c 100644
--- a/mysql-test/t/subselect2.test
+++ b/mysql-test/t/subselect2.test
@@ -8,6 +8,9 @@
 drop table if exists t1, t2, t3, t4;
 --enable_warnings
 
+set @subselect2_test_tmp=@@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on';
+
 CREATE TABLE t1
 (
 DOCID VARCHAR(32)BINARY NOT NULL
@@ -168,3 +171,6 @@ SELECT t1.* FROM t1 WHERE (SELECT COUNT(*) FROM t3,t2 WHERE t3.c=t2.a
                            and t2.a='1' AND t1.a=t3.b) > 0;
 
 DROP TABLE t1,t2,t3;
+
+set optimizer_switch=@subselect2_test_tmp;
+
diff --git a/mysql-test/t/subselect3.test b/mysql-test/t/subselect3.test
index 0c1523a04ca..73ee11eb78d 100644
--- a/mysql-test/t/subselect3.test
+++ b/mysql-test/t/subselect3.test
@@ -2,7 +2,8 @@
 drop table if exists t0, t1, t2, t3, t4, t5, t11, t12, t21, t22;
 --enable_warnings
 
-set @save_optimizer_switch=@@optimizer_switch;
+set @subselect3_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 
 #
 # 1. Subquery with GROUP/HAVING
@@ -538,7 +539,6 @@ SELECT a, MAX(b),
 DROP TABLE t1, t2;
 
 # The next three test cases must be executed with the IN=>EXISTS strategy
-set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
 
 #
@@ -906,7 +906,8 @@ set @@optimizer_switch='firstmatch=off,materialization=off';
 insert into t0 values(2);
 explain select * from t1 where 2 in (select a from t0);
 select * from t1 where 2 in (select a from t0);
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch='materialization=off';
 explain select * from t1 where 2 in (select a from t0);
 select * from t1 where 2 in (select a from t0);
 set @@optimizer_switch=@save_optimizer_switch;
@@ -1160,7 +1161,7 @@ drop table t1,t2,t3;
 --echo # BUG#47367 Crash in Name_resolution_context::process_error
 --echo #
 
-SET SESSION optimizer_switch = 'default,semijoin=off';
+SET SESSION optimizer_switch = 'semijoin=off';
 CREATE TABLE t1 (f1 INTEGER);
 CREATE TABLE t2 LIKE t1;
 delimiter |;
@@ -1186,4 +1187,4 @@ DROP PROCEDURE p1;
 DROP TABLE t1, t2;
 
 # The following command must be the last one the file 
-set @@optimizer_switch=@save_optimizer_switch;
+set @@optimizer_switch=@subselect3_tmp;
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index 39561d5114f..bed28400c2c 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -4,6 +4,9 @@
 drop table if exists t1,t2,t3,t4,t5,t6;
 --enable_warnings
 
+set @subselect4_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
+
 --echo #
 --echo # Bug #46791: Assertion failed:(table->key_read==0),function unknown
 --echo #    function,file sql_base.cc
@@ -1415,3 +1418,5 @@ WHERE t2.f1 = (
                 FROM t1));
 
 drop table t1, t2, t3;
+
+set optimizer_switch=@subselect4_tmp;
diff --git a/mysql-test/t/subselect_mat.test b/mysql-test/t/subselect_mat.test
index 9d6eb2775ab..172ef651407 100644
--- a/mysql-test/t/subselect_mat.test
+++ b/mysql-test/t/subselect_mat.test
@@ -5,9 +5,11 @@
 
 
 # force the use of materialization
-set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
+set @subselect_mat_test_optimizer_switch_value='materialization=on,in_to_exists=off,semijoin=off';
 
 --source t/subselect_sj_mat.test
+set @subselect_mat_test_optimizer_switch_value=null;
+
 set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
 #
 # Test that the contents of the temp table of a materialized subquery is
diff --git a/mysql-test/t/subselect_no_opts.test b/mysql-test/t/subselect_no_opts.test
index d72deab45bf..a29fa5a27ac 100644
--- a/mysql-test/t/subselect_no_opts.test
+++ b/mysql-test/t/subselect_no_opts.test
@@ -1,9 +1,9 @@
 # 
 # Run subselect.test without semi-join and materialization optimizations
 #  (test in-to-exists)
-set optimizer_switch='materialization=off,semijoin=off';
 
+set @optimizer_switch_for_subselect_test='materialization=off,semijoin=off'; 
 --source t/subselect.test
 
-set optimizer_switch=default;
+set @optimizer_switch_for_subselect_test=null; 
 
diff --git a/mysql-test/t/subselect_no_semijoin.test b/mysql-test/t/subselect_no_semijoin.test
index e9f2e0654ce..b8bcb6c4600 100644
--- a/mysql-test/t/subselect_no_semijoin.test
+++ b/mysql-test/t/subselect_no_semijoin.test
@@ -1,8 +1,8 @@
 # 
 # Run subselect.test without semi-join optimization (test materialize)
 #
-set optimizer_switch='semijoin=off';
+set @optimizer_switch_for_subselect_test='semijoin=off'; 
 
 --source t/subselect.test
 
-set optimizer_switch=default;
+set @optimizer_switch_for_subselect_test=null; 
diff --git a/mysql-test/t/subselect_sj.test b/mysql-test/t/subselect_sj.test
index 0c12cfd4be0..46c8306e144 100644
--- a/mysql-test/t/subselect_sj.test
+++ b/mysql-test/t/subselect_sj.test
@@ -7,6 +7,9 @@ drop view if exists v1, v2;
 drop procedure if exists p1;
 --enable_warnings
 
+set @subselect_sj_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
+# The 'default' value within the scope of this test:
 set @save_optimizer_switch=@@optimizer_switch;
 
 #
@@ -1396,4 +1399,4 @@ DROP TABLE t1, t2;
 set optimizer_switch=@save_802965;
 
 # The following command must be the last one the file 
-set @@optimizer_switch=@save_optimizer_switch;
+set optimizer_switch=@subselect_sj_tmp;
diff --git a/mysql-test/t/subselect_sj2.test b/mysql-test/t/subselect_sj2.test
index f4573a94407..7caf5da7b8b 100644
--- a/mysql-test/t/subselect_sj2.test
+++ b/mysql-test/t/subselect_sj2.test
@@ -2,6 +2,9 @@
 # DuplicateElimination strategy test
 #
 --source include/have_innodb.inc
+
+set @subselect_sj2_tmp= @@optimizer_switch;
+set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 --disable_warnings
 drop table if exists t0, t1, t2, t3;
 drop view if exists v1;
@@ -939,3 +942,5 @@ WHERE alias2.f11 IN (
 )
 GROUP BY field2;
 drop table t1, t2, t3;
+
+set optimizer_switch=@subselect_sj2_tmp;
diff --git a/mysql-test/t/subselect_sj_jcl6.test b/mysql-test/t/subselect_sj_jcl6.test
index 086d3bfaa4e..fb5b7ab5655 100644
--- a/mysql-test/t/subselect_sj_jcl6.test
+++ b/mysql-test/t/subselect_sj_jcl6.test
@@ -3,6 +3,7 @@
 #
 
 set @save_optimizer_switch_jcl6=@@optimizer_switch;
+set @@optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set @@optimizer_switch='semijoin_with_cache=on';
 set @@optimizer_switch='outer_join_with_cache=on';
 set @@optimizer_switch='join_cache_hashed=off';
diff --git a/mysql-test/t/subselect_sj_mat.test b/mysql-test/t/subselect_sj_mat.test
index 728945be880..db798e27037 100644
--- a/mysql-test/t/subselect_sj_mat.test
+++ b/mysql-test/t/subselect_sj_mat.test
@@ -3,6 +3,10 @@
 # (WL#1110: Subquery optimization: materialization)
 #
 
+set @subselect_sj_mat_tmp= @@optimizer_switch;
+set optimizer_switch=ifnull(@subselect_mat_test_optimizer_switch_value, 'semijoin=on,firstmatch=on,loosescan=on');
+set @optimizer_switch_local_default= @@optimizer_switch;
+
 --disable_warnings
 drop table if exists t1, t2, t3, t1i, t2i, t3i;
 drop table if exists columns;
@@ -121,20 +125,26 @@ select * from t1 where (a1, a2) in (select b1, min(b2) from t2i limit 1,1);
 # test re-optimization/re-execution with different execution methods
 # prepare once, exec with different modes
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
 
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 execute st1;
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 execute st1;
 set @@optimizer_switch=@save_optimizer_switch;
 
@@ -826,18 +836,21 @@ explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 # Query with group by, executed via IN=>EXISTS
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 
 # Executed with materialization
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 select min(a1) from t1 where 7 in (select b1 from t2);
 # Executed with semi-join. Notice, this time we get a different result (NULL).
 # This is the only correct result of all four queries. This difference is
 # filed as BUG#40037.
-set @@optimizer_switch='default,materialization=off';
+set @@optimizer_switch=@optimizer_switch_local_default;
+set @@optimizer_switch='materialization=off,in_to_exists=on';
 -- echo # with MariaDB and MWL#90, this particular case is solved:
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 select min(a1) from t1 where 7 in (select b1 from t2);
@@ -875,7 +888,8 @@ INSERT INTO t2 VALUES (1, 1.789);
 INSERT INTO t2 VALUES (13, 1.454);
 
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 set @@optimizer_switch= @save_optimizer_switch;
@@ -899,7 +913,8 @@ CREATE TABLE t2 LIKE t1;
 INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii'),(2,'f','ffff','ffff','ffff');
 
 set @save_optimizer_switch=@@optimizer_switch;
-SET @@optimizer_switch='default,semijoin=on,materialization=on';
+set @@optimizer_switch=@optimizer_switch_local_default;
+SET @@optimizer_switch='semijoin=on,materialization=on';
 EXPLAIN SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 SELECT pk FROM t1 WHERE (b,c,d) IN (SELECT b,c,d FROM t2 WHERE pk > 0);
@@ -972,3 +987,6 @@ explain select left(a1,7), left(a2,7) from t1_1024 where (a1,3) in (select subst
 select left(a1,7), left(a2,7) from t1_1024 where (a1,3) in (select substring(b1,1,1024), count(*) from t2_1024 where b1 > '0');
 
 drop table t1_1024, t2_1024;
+
+set optimizer_switch=@subselect_sj_mat_tmp;
+
diff --git a/mysql-test/t/subselect_sj_nonmerged.test b/mysql-test/t/subselect_sj_nonmerged.test
index 5c8fb6db424..f60871c9dd9 100644
--- a/mysql-test/t/subselect_sj_nonmerged.test
+++ b/mysql-test/t/subselect_sj_nonmerged.test
@@ -6,7 +6,7 @@ drop table if exists t0, t1, t2, t3, t4;
 --enable_warnings
 
 set @save_optimizer_switch=@@optimizer_switch;
-set optimizer_switch='materialization=on';
+set optimizer_switch='semijoin=on,materialization=on';
 
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);