MWL#90: Subqueries: Inside-out execution for materialized non-sj subqueries

- Merge into 5.3-main

1 files changed, 48 insertions, 33 deletions

diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 537129a4434..5a69dc2333b 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -1,3 +1,5 @@
+set @@optimizer_switch='semijoin=off';
+set optimizer_switch='firstmatch=off';
 drop table if exists t1, t2, t3, t1i, t2i, t3i;
 drop view if exists v1, v2, v1m, v2m;
 create table t1 (a1 char(8), a2 char(8));
@@ -30,7 +32,6 @@ create index it3i3 on t3i (c1, c2);
 insert into t1i select * from t1;
 insert into t2i select * from t2;
 insert into t3i select * from t3;
-set @@optimizer_switch='semijoin=off';
 /******************************************************************************
 * Simple tests.
 ******************************************************************************/
@@ -82,8 +83,8 @@ a1	a2
 explain extended
 select * from t1i where a1 in (select b1 from t2i where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-2	SUBQUERY	t2i	index	it2i1,it2i3	it2i1	9	NULL	5	100.00	Using where; Using index
+1	PRIMARY	t1i	index	NULL	_it1_idx	#	NULL	3	100.00	Using where; 
+2	SUBQUERY	t2i	index	it2i1,it2i3	it2i1	#	NULL	5	100.00	Using where; 
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a1`>(<in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`))))))
 select * from t1i where a1 in (select b1 from t2i where b1 > '0');
@@ -93,8 +94,8 @@ a1	a2
 explain extended
 select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-2	SUBQUERY	t2i	range	it2i1,it2i3	it2i1	9	NULL	3	100.00	Using where; Using index for group-by
+1	PRIMARY	t1i	index	NULL	#	18	#	3	100.00	#
+2	SUBQUERY	t2i	range	it2i1,it2i3	#	9	#	3	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a1`>(<in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`))))))
 select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
@@ -104,8 +105,8 @@ a1	a2
 explain extended
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-2	SUBQUERY	t2i	index	it2i1,it2i3	it2i3	18	NULL	5	100.00	Using where; Using index
+1	PRIMARY	t1i	index	NULL	_it1_idx	#	NULL	3	100.00	Using where; 
+2	SUBQUERY	t2i	index	it2i1,it2i3	it2i3	#	NULL	5	100.00	Using where; 
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`b2`))))))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
@@ -115,8 +116,8 @@ a1	a2
 explain extended
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-2	SUBQUERY	t2i	range	it2i1,it2i3	it2i3	18	NULL	3	100.00	Using where; Using index for group-by
+1	PRIMARY	t1i	index	NULL	#	#	#	3	100.00	#
+2	SUBQUERY	t2i	range	it2i1,it2i3	#	#	#	3	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`,`test`.`t2i`.`b2` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`b2`))))))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
@@ -126,8 +127,8 @@ a1	a2
 explain extended
 select * from t1i where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-2	SUBQUERY	t2i	range	it2i1,it2i3	it2i3	18	NULL	3	100.00	Using where; Using index for group-by
+1	PRIMARY	t1i	index	NULL	#	#	#	3	100.00	#
+2	SUBQUERY	t2i	range	it2i1,it2i3	#	#	#	3	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1`,min(`test`.`t2i`.`b2`) from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`min(b2)`))))))
 select * from t1i where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
@@ -176,6 +177,7 @@ a1	a2
 1 - 02	2 - 02
 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';
 prepare st1 from
 "select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1)";
@@ -202,7 +204,7 @@ execute st1;
 a1	a2
 1 - 01	2 - 01
 1 - 02	2 - 02
-set @@optimizer_switch='default,semijoin=off';
+set @@optimizer_switch=@save_optimizer_switch;
 explain extended
 select * from t1 where (a1, a2) in (select b1, b2 from t2 order by b1, b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -289,10 +291,10 @@ where (a1, a2) in (select b1, b2 from t2i where b1 >  '0') and
 (a1, a2) in (select c1, c2 from t3i
 where (c1, c2) in (select b1, b2 from t2i where b2 > '0'));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-3	SUBQUERY	t3i	index	NULL	it3i3	18	NULL	4	100.00	Using where; Using index
-4	SUBQUERY	t2i	index	it2i2	it2i3	18	NULL	5	100.00	Using where; Using index
-2	SUBQUERY	t2i	index	it2i1,it2i3	it2i3	18	NULL	5	100.00	Using where; Using index
+1	PRIMARY	t1i	index	NULL	#	#	#	3	100.00	#
+3	SUBQUERY	t3i	index	NULL	#	#	#	4	100.00	#
+4	SUBQUERY	t2i	index	it2i2	#	#	#	5	100.00	#
+2	SUBQUERY	t2i	index	it2i1,it2i3	#	#	#	5	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where (<expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`b2`)))))) and <expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1`,`test`.`t3i`.`c2` from `test`.`t3i` where <expr_cache><`test`.`t3i`.`c2`,`test`.`t3i`.`c1`>(<in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b2` > '0') ), <primary_index_lookup>(`test`.`t3i`.`c1` in <temporary table> on distinct_key where ((`test`.`t3i`.`c1` = `materialized subselect`.`b1`) and (`test`.`t3i`.`c2` = `materialized subselect`.`b2`)))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`c1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`c2`)))))))
 select * from t1i
@@ -366,17 +368,17 @@ where (a1, a2) in (select b1, b2 from t2i where b1 >  '0') and
 (a1, a2) in (select c1, c2 from t3i
 where (c1, c2) in (select b1, b2 from t2i where b2 > '0')));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-5	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
-6	SUBQUERY	t2i	index	it2i2	it2i3	18	NULL	5	100.00	Using where; Using index
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
-4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
-7	UNION	t1i	index	NULL	it1i3	18	NULL	3	100.00	Using where; Using index
-9	SUBQUERY	t3i	index	NULL	it3i3	18	NULL	4	100.00	Using where; Using index
-10	SUBQUERY	t2i	index	it2i2	it2i3	18	NULL	5	100.00	Using where; Using index
-8	SUBQUERY	t2i	index	it2i1,it2i3	it2i3	18	NULL	5	100.00	Using where; Using index
-NULL	UNION RESULT	<union1,7>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
+1	PRIMARY	t1	ALL	NULL	#	#	#	3	100.00	#
+5	SUBQUERY	t3	ALL	NULL	#	#	#	4	100.00	#
+6	SUBQUERY	t2i	index	it2i2	#	#	#	5	100.00	#
+2	SUBQUERY	t2	ALL	NULL	#	#	#	5	100.00	#
+4	SUBQUERY	t3	ALL	NULL	#	#	#	4	100.00	#
+3	SUBQUERY	t3	ALL	NULL	#	#	#	4	100.00	#
+7	UNION	t1i	index	NULL	#	#	#	3	100.00	#
+9	SUBQUERY	t3i	index	NULL	#	#	#	4	100.00	#
+10	SUBQUERY	t2i	index	it2i2	#	#	#	5	100.00	#
+8	SUBQUERY	t2i	index	it2i1,it2i3	#	#	#	5	100.00	#
+NULL	UNION RESULT	<union1,7>	ALL	NULL	#	#	#	NULL	NULL	#
 Warnings:
 Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<expr_cache><`test`.`t1`.`a2`,`test`.`t1`.`a1`>(<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1`,`test`.`t2`.`b2` from `test`.`t2` where (<expr_cache><`test`.`t2`.`b2`>(<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%02') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `materialized subselect`.`c2`)))))) or <expr_cache><`test`.`t2`.`b2`>(<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` from `test`.`t3` where (`test`.`t3`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `materialized subselect`.`c2`))))))) group by `test`.`t2`.`b1`,`test`.`t2`.`b2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1`.`a2` = `materialized subselect`.`b2`)))))) and <expr_cache><`test`.`t1`.`a2`,`test`.`t1`.`a1`>(<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1`,`test`.`t3`.`c2` from `test`.`t3` where <expr_cache><`test`.`t3`.`c2`,`test`.`t3`.`c1`>(<in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b2` > '0') ), <primary_index_lookup>(`test`.`t3`.`c1` in <temporary table> on distinct_key where ((`test`.`t3`.`c1` = `materialized subselect`.`b1`) and (`test`.`t3`.`c2` = `materialized subselect`.`b2`)))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `materialized subselect`.`c1`) and (`test`.`t1`.`a2` = `materialized subselect`.`c2`)))))))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where (<expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`b1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`b2`)))))) and <expr_cache><`test`.`t1i`.`a2`,`test`.`t1i`.`a1`>(<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1`,`test`.`t3i`.`c2` from `test`.`t3i` where <expr_cache><`test`.`t3i`.`c2`,`test`.`t3i`.`c1`>(<in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1`,`test`.`t2i`.`b2` from `test`.`t2i` where (`test`.`t2i`.`b2` > '0') ), <primary_index_lookup>(`test`.`t3i`.`c1` in <temporary table> on distinct_key where ((`test`.`t3i`.`c1` = `materialized subselect`.`b1`) and (`test`.`t3i`.`c2` = `materialized subselect`.`b2`)))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `materialized subselect`.`c1`) and (`test`.`t1i`.`a2` = `materialized subselect`.`c2`))))))))
 (select * from t1
@@ -549,7 +551,6 @@ a1	a2
 Test that BLOBs are not materialized (except when arguments of some functions).
 */
 # force materialization to be always considered
-set @@optimizer_switch='semijoin=off';
 set @prefix_len = 6;
 set @blob_len = 16;
 set @suffix_len = @blob_len - @prefix_len;
@@ -951,7 +952,6 @@ insert into t1bit values (b'010', b'110');
 insert into t2bit values (b'001', b'101');
 insert into t2bit values (b'010', b'110');
 insert into t2bit values (b'110', b'111');
-set @@optimizer_switch='semijoin=off';
 explain extended select bin(a1), bin(a2)
 from t1bit
 where (a1, a2) in (select b1, b2 from t2bit);
@@ -994,7 +994,7 @@ drop table t1, t2, t3, t1i, t2i, t3i, columns;
 /******************************************************************************
 * Test the cache of the left operand of IN.
 ******************************************************************************/
-set @@optimizer_switch='semijoin=off';
+# Test that default values of Cached_item are not used for comparison
 create table t1 (s1 int);
 create table t2 (s2 int);
 insert into t1 values (5),(1),(0);
@@ -1142,6 +1142,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 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 group by b1);
 min(a1)
+set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch='default,materialization=off';
 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
@@ -1157,17 +1158,25 @@ 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);
 min(a1)
 set @@optimizer_switch='default,materialization=off';
+# 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
 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
+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) or 2> 4;
+min(a1)
+set @@optimizer_switch= @save_optimizer_switch;
 drop table t1,t2;
 create table t1 (a char(2), b varchar(10));
 insert into t1 values ('a',  'aaa');
 insert into t1 values ('aa', 'aaaa');
-set @@optimizer_switch='default,semijoin=off';
 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	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -1187,15 +1196,17 @@ INSERT INTO t1 (f1, f2) VALUES (10, 1.668);
 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';
 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	subselect2	ALL	unique_key	NULL	NULL	NULL	2	
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 COUNT(*)
 2
+set @@optimizer_switch= @save_optimizer_switch;
 DROP TABLE t1, t2;
 CREATE TABLE t1 (
 pk int,
@@ -1208,11 +1219,12 @@ PRIMARY KEY (pk)
 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';
 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	
-1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
 2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	2	Using index condition; Using MRR
 SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
 pk
@@ -1221,6 +1233,7 @@ SELECT pk FROM t1 WHERE (b,c,d) IN (SELECT b,c,d FROM t2 WHERE pk > 0);
 pk
 2
 DROP TABLE t1, t2;
+set optimizer_switch=@save_optimizer_switch;
 #
 # BUG#50019: Wrong result for IN-subquery with materialization
 #
@@ -1272,6 +1285,8 @@ a	a in (select a from t1)
 1	0
 2	0
 drop table t0, t1;
+set optimizer_switch='firstmatch=on';
+set @@optimizer_switch=default;
 #
 # LPBUG#609121: RQG: wrong result on aggregate + NOT IN + HAVING and
 # partial_match_table_scan=on