MWL#90: Subqueries: Inside-out execution for non-semijoin materialized...

MWL#90: Subqueries: Inside-out execution for non-semijoin materialized subqueries that are AND-parts of the WHERE
- Change "SUBQUERY#n" to "<subquery{n}>" in EXPLAIN output. We need to it to be
  lowercase so that EXPLAIN results do not differ in case between systems with
  case-sensitive and case-insensitive filesystems.
- Remove garbage comments, add better comments.

mysql-test/r/group_min_max.result

@@ -2255,8 +2255,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	distinct_key	NULL	NULL	NULL	8	
-1	PRIMARY	t1_outer	ref	a	a	5	SUBQUERY#2.max(b)	2	Using index
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	8	
+1	PRIMARY	t1_outer	ref	a	a	5	<subquery2>.max(b)	2	Using index
 2	SUBQUERY	t1	range	NULL	a	5	NULL	8	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 
 a > (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);

mysql-test/r/subselect.result

@@ -3418,7 +3418,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
@@ -3430,7 +3430,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	9	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	23	test.t1.a,test.t1.b	1	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
@@ -4325,17 +4325,17 @@ INSERT INTO t1 VALUES (1),(2);
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
 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	
-1	PRIMARY	SUBQUERY#2	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 1 AS `1` from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`SUBQUERY#2`.`1` = 1)
+Note	1003	select 1 AS `1` from  <materialize> (select 1 AS `1` from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`1` = 1)
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 WHERE a > 3 GROUP BY a);
 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	
-1	PRIMARY	SUBQUERY#2	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 1 AS `1` from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`SUBQUERY#2`.`1` = 1)
+Note	1003	select 1 AS `1` from  <materialize> (select 1 AS `1` from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`1` = 1)
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.

mysql-test/r/subselect3.result

@@ -1017,7 +1017,7 @@ update t22 set c = '2005-12-08 15:58:27' where a = 255;
 explain select t21.* from t21,t22 where t21.a = t22.a and 
 t22.a in (select t12.a from t11, t12 where t11.a in(255,256) and t11.a = t12.a and t11.c is null) and t22.c is null order by t21.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	8	Using temporary; Using filesort
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	8	Using temporary; Using filesort
 1	PRIMARY	t21	ALL	NULL	NULL	NULL	NULL	26	Using where; Using join buffer
 1	PRIMARY	t22	ALL	NULL	NULL	NULL	NULL	26	Using where; Using join buffer
 2	SUBQUERY	t11	ALL	NULL	NULL	NULL	NULL	8	Using where
@@ -1035,7 +1035,7 @@ select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) a
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	2	
 2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	DEPENDENT SUBQUERY	SUBQUERY#3	eq_ref	unique_key	unique_key	5	func	1	
+2	DEPENDENT SUBQUERY	<subquery3>	eq_ref	unique_key	unique_key	5	func	1	
 3	SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	2	
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 subq
@@ -1158,7 +1158,7 @@ create table t3 ( a int , filler char(100), key(a));
 insert into t3 select A.a + 10*B.a, 'filler' from t0 A, t0 B;
 explain select * from t3 where a in (select a from t2) and (a > 5 or a < 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	2	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 select * from t3 where a in (select a from t2);
@@ -1207,25 +1207,25 @@ insert into t3 select A.a + 10*B.a, A.a + 10*B.a, 'filler' from t1 A, t1 B, t1 C
 explain select * from t1, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30) and t1.a =3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where
 explain select straight_join * from t1 A, t1 B where A.a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.A.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.A.a	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	
 explain select * from t2 where a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 explain select * from t2 where a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 explain select straight_join * from t2 X, t2 Y 
@@ -1233,7 +1233,7 @@ where X.a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	Y	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.X.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.X.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 create table t0 (a int, b int);
@@ -1241,14 +1241,14 @@ insert into t0 values(1,1);
 explain select * from t0, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where
 create table t4 as select a as x, a as y from t1;
 explain select * from t0, t3 where (t3.a, t3.b) in (select x,y from t4) and (t3.a < 10 or t3.a >30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t4.x	10	Using where
 2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	10	Using where
 drop table t0,t1,t2,t3,t4;
@@ -1274,14 +1274,14 @@ set @@optimizer_switch='firstmatch=off';
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	10	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	10	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	100	
 set @save_optimizer_search_depth=@@optimizer_search_depth;
 set @@optimizer_search_depth=63;
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	10	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	10	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	100	
 set @@optimizer_search_depth=@save_optimizer_search_depth;
 set @@optimizer_switch=default;
@@ -1320,7 +1320,7 @@ insert into t2 select * from t2;
 explain select * from t1 where (a,b,c) in (select X.a, Y.a, Z.a from t2 X, t2 Y, t2 Z where X.b=33);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	15	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	15	func	1	
 2	SUBQUERY	X	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	6	Using join buffer
 2	SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	6	Using join buffer
@@ -1393,7 +1393,7 @@ INNER JOIN t2 c ON c.idContact=cona.idContact
 WHERE cona.postalStripped='T2H3B2'
 	);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	1.00	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	2	1.00	
 1	PRIMARY	a	index	PRIMARY	PRIMARY	4	NULL	2	100.00	Using where; Using index; Using join buffer
 2	SUBQUERY	cona	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 2	SUBQUERY	c	eq_ref	PRIMARY	PRIMARY	4	test.cona.idContact	1	100.00	

mysql-test/r/subselect3_jcl6.result

@@ -1021,7 +1021,7 @@ update t22 set c = '2005-12-08 15:58:27' where a = 255;
 explain select t21.* from t21,t22 where t21.a = t22.a and 
 t22.a in (select t12.a from t11, t12 where t11.a in(255,256) and t11.a = t12.a and t11.c is null) and t22.c is null order by t21.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	8	Using temporary; Using filesort
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	8	Using temporary; Using filesort
 1	PRIMARY	t21	ALL	NULL	NULL	NULL	NULL	26	Using where; Using join buffer
 1	PRIMARY	t22	ALL	NULL	NULL	NULL	NULL	26	Using where; Using join buffer
 2	SUBQUERY	t11	ALL	NULL	NULL	NULL	NULL	8	Using where
@@ -1040,7 +1040,7 @@ select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) a
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	2	
 2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	DEPENDENT SUBQUERY	SUBQUERY#3	eq_ref	unique_key	unique_key	5	func	1	
+2	DEPENDENT SUBQUERY	<subquery3>	eq_ref	unique_key	unique_key	5	func	1	
 3	SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	2	
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 subq
@@ -1163,7 +1163,7 @@ create table t3 ( a int , filler char(100), key(a));
 insert into t3 select A.a + 10*B.a, 'filler' from t0 A, t0 B;
 explain select * from t3 where a in (select a from t2) and (a > 5 or a < 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	2	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	1	Using join buffer
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 select * from t3 where a in (select a from t2);
@@ -1212,25 +1212,25 @@ insert into t3 select A.a + 10*B.a, A.a + 10*B.a, 'filler' from t1 A, t1 B, t1 C
 explain select * from t1, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30) and t1.a =3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	Using join buffer
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where
 explain select straight_join * from t1 A, t1 B where A.a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.A.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.A.a	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	
 explain select * from t2 where a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 explain select * from t2 where a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t2.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 explain select straight_join * from t2 X, t2 Y 
@@ -1238,7 +1238,7 @@ where X.a in (select straight_join A.a from t1 A, t1 B);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	Y	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	5	test.X.a	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.X.a	1	
 2	SUBQUERY	A	ALL	NULL	NULL	NULL	NULL	10	
 2	SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
 create table t0 (a int, b int);
@@ -1246,14 +1246,14 @@ insert into t0 values(1,1);
 explain select * from t0, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	Using join buffer
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where
 create table t4 as select a as x, a as y from t1;
 explain select * from t0, t3 where (t3.a, t3.b) in (select x,y from t4) and (t3.a < 10 or t3.a >30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	a	a	5	test.t4.x	10	Using where; Using join buffer
 2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	10	Using where
 drop table t0,t1,t2,t3,t4;
@@ -1279,14 +1279,14 @@ set @@optimizer_switch='firstmatch=off';
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	10	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	10	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	100	
 set @save_optimizer_search_depth=@@optimizer_search_depth;
 set @@optimizer_search_depth=63;
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	10	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	10	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	100	
 set @@optimizer_search_depth=@save_optimizer_search_depth;
 set @@optimizer_switch=default;
@@ -1325,7 +1325,7 @@ insert into t2 select * from t2;
 explain select * from t1 where (a,b,c) in (select X.a, Y.a, Z.a from t2 X, t2 Y, t2 Z where X.b=33);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	15	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	15	func	1	
 2	SUBQUERY	X	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	6	Using join buffer
 2	SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	6	Using join buffer
@@ -1398,7 +1398,7 @@ INNER JOIN t2 c ON c.idContact=cona.idContact
 WHERE cona.postalStripped='T2H3B2'
 	);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	1.00	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	2	1.00	
 1	PRIMARY	a	index	PRIMARY	PRIMARY	4	NULL	2	100.00	Using where; Using index; Using join buffer
 2	SUBQUERY	cona	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 2	SUBQUERY	c	eq_ref	PRIMARY	PRIMARY	4	test.cona.idContact	1	100.00	Using join buffer

mysql-test/r/subselect4.result

@@ -216,7 +216,7 @@ FROM t2
 WHERE PTYPE = 'Design'));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
@@ -231,13 +231,13 @@ WHERE EMPNUM IN
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	SIMPLE	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	SIMPLE	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 DEALLOCATE PREPARE stmt;
@@ -254,7 +254,7 @@ FROM t2
 WHERE PTYPE = 'Design'));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
@@ -269,13 +269,13 @@ WHERE EMPNUM IN
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
-1	SIMPLE	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	SIMPLE	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 DEALLOCATE PREPARE stmt;
@@ -291,7 +291,7 @@ FROM t2
 WHERE PTYPE = 'Design'));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
@@ -306,13 +306,13 @@ WHERE EMPNUM IN
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	SIMPLE	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	SIMPLE	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
 DEALLOCATE PREPARE stmt;

mysql-test/r/subselect_mat.result

@@ -42,7 +42,7 @@ 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
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`)))))
 select * from t1 where a1 in (select b1 from t2 where b1 > '0');
 a1	a2
 1 - 01	2 - 01
@@ -53,7 +53,7 @@ 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
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`)))))
 select * from t1 where a1 in (select b1 from t2 where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -64,7 +64,7 @@ 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
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`,`test`.`t2`.`b2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`,`test`.`t2`.`b2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`)))))
 select * from t1 where (a1, a2) in (select b1, b2 from t2 where b1 > '0' group by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -75,7 +75,7 @@ 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
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,min(`test`.`t2`.`b2`) AS `min(b2)` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`min(b2)`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,min(`test`.`t2`.`b2`) AS `min(b2)` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`min(b2)`)))))
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -86,7 +86,7 @@ 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
 Warnings:
-Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` AS `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` = `SUBQUERY#2`.`b1`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` AS `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` = `<subquery2>`.`b1`)))))
 select * from t1i where a1 in (select b1 from t2i where b1 > '0');
 a1	a2
 1 - 01	2 - 01
@@ -97,7 +97,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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 <in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` AS `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` = `SUBQUERY#2`.`b1`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select `test`.`t2i`.`b1` AS `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` = `<subquery2>`.`b1`)))))
 select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -108,7 +108,7 @@ 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
 Warnings:
-Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#2`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery2>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery2>`.`b2`)))))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
 a1	a2
 1 - 01	2 - 01
@@ -119,7 +119,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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 <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#2`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery2>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery2>`.`b2`)))))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -130,7 +130,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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 <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(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` = `SUBQUERY#2`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#2`.`min(b2)`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(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` = `<subquery2>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery2>`.`min(b2)`)))))
 select * from t1i where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -141,7 +141,7 @@ 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
 2	SUBQUERY	t2i	range	NULL	it2i3	9	NULL	3	100.00	Using index for group-by
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,max(`test`.`t2i`.`b2`) AS `max(b2)` from `test`.`t2i` group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`max(b2)`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,max(`test`.`t2i`.`b2`) AS `max(b2)` from `test`.`t2i` group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`max(b2)`)))))
 select * from t1 where (a1, a2) in (select b1, max(b2) from t2i group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -170,7 +170,7 @@ 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
 2	SUBQUERY	t2i	range	it2i1,it2i3	it2i3	18	NULL	3	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`min(b2)`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`min(b2)`)))))
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -211,7 +211,7 @@ 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
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` order by `test`.`t2`.`b1`,`test`.`t2`.`b2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` order by `test`.`t2`.`b1`,`test`.`t2`.`b2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`)))))
 select * from t1 where (a1, a2) in (select b1, b2 from t2 order by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -222,7 +222,7 @@ 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	NULL	it2i3	18	NULL	5	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` order by `test`.`t2i`.`b1`,`test`.`t2i`.`b2` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` order by `test`.`t2i`.`b1`,`test`.`t2i`.`b2` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery2>`.`b2`)))))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i order by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -277,7 +277,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 4	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
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#4`.`b1`) and (`test`.`t3`.`c2` = `SUBQUERY#4`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#3`.`c1`) and (`test`.`t1`.`a2` = `SUBQUERY#3`.`c2`))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery4>`.`b1`) and (`test`.`t3`.`c2` = `<subquery4>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery3>`.`c1`) and (`test`.`t1`.`a2` = `<subquery3>`.`c2`))))))
 select * from t1
 where (a1, a2) in (select b1, b2 from t2 where b1 >  '0') and
 (a1, a2) in (select c1, c2 from t3
@@ -296,7 +296,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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 (<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#2`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#2`.`b2`))))) and <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1` AS `c1`,`test`.`t3i`.`c2` AS `c2` from `test`.`t3i` where <in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#4`.`b1`) and (`test`.`t3i`.`c2` = `SUBQUERY#4`.`b2`))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `SUBQUERY#3`.`c1`) and (`test`.`t1i`.`a2` = `SUBQUERY#3`.`c2`))))))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where (<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery2>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery2>`.`b2`))))) and <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1` AS `c1`,`test`.`t3i`.`c2` AS `c2` from `test`.`t3i` where <in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery4>`.`b1`) and (`test`.`t3i`.`c2` = `<subquery4>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `<subquery3>`.`c1`) and (`test`.`t1i`.`a2` = `<subquery3>`.`c2`))))))
 select * from t1i
 where (a1, a2) in (select b1, b2 from t2i where b1 >  '0') and
 (a1, a2) in (select c1, c2 from t3i
@@ -319,7 +319,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#3`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#4`.`c2`)))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#6`.`b1`) and (`test`.`t3`.`c2` = `SUBQUERY#6`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#5`.`c1`) and (`test`.`t1`.`a2` = `SUBQUERY#5`.`c2`))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery4>`.`c2`)))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery6>`.`b1`) and (`test`.`t3`.`c2` = `<subquery6>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery5>`.`c1`) and (`test`.`t1`.`a2` = `<subquery5>`.`c2`))))))
 select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 where c2 LIKE '%02') or
@@ -344,7 +344,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	DEPENDENT SUBQUERY	t3a	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'test.t1.a1' of SELECT #3 was resolved in SELECT #1
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `SUBQUERY#4`.`c2`)))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3c`.`c1` AS `c1`,`test`.`t3c`.`c2` AS `c2` from `test`.`t3` `t3c` where <in_optimizer>((`test`.`t3c`.`c1`,`test`.`t3c`.`c2`),(`test`.`t3c`.`c1`,`test`.`t3c`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` where (`test`.`t2i`.`b2` > '0') ), <primary_index_lookup>(`test`.`t3c`.`c1` in <temporary table> on distinct_key where ((`test`.`t3c`.`c1` = `SUBQUERY#6`.`b1`) and (`test`.`t3c`.`c2` = `SUBQUERY#6`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#5`.`c1`) and (`test`.`t1`.`a2` = `SUBQUERY#5`.`c2`))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3c`.`c1` AS `c1`,`test`.`t3c`.`c2` AS `c2` from `test`.`t3` `t3c` where <in_optimizer>((`test`.`t3c`.`c1`,`test`.`t3c`.`c2`),(`test`.`t3c`.`c1`,`test`.`t3c`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` where (`test`.`t2i`.`b2` > '0') ), <primary_index_lookup>(`test`.`t3c`.`c1` in <temporary table> on distinct_key where ((`test`.`t3c`.`c1` = `<subquery6>`.`b1`) and (`test`.`t3c`.`c2` = `<subquery6>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery5>`.`c1`) and (`test`.`t1`.`a2` = `<subquery5>`.`c2`))))))
 select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 t3a where c1 = a1) or
@@ -380,7 +380,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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 (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#3`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#4`.`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` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#6`.`b1`) and (`test`.`t3`.`c2` = `SUBQUERY#6`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#5`.`c1`) and (`test`.`t1`.`a2` = `SUBQUERY#5`.`c2`))))))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where (<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#8`.`b1`) and (`test`.`t1i`.`a2` = `SUBQUERY#8`.`b2`))))) and <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1` AS `c1`,`test`.`t3i`.`c2` AS `c2` from `test`.`t3i` where <in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#10`.`b1`) and (`test`.`t3i`.`c2` = `SUBQUERY#10`.`b2`))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `SUBQUERY#9`.`c1`) and (`test`.`t1i`.`a2` = `SUBQUERY#9`.`c2`)))))))
+Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery4>`.`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` = `<subquery2>`.`b1`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`))))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery6>`.`b1`) and (`test`.`t3`.`c2` = `<subquery6>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery5>`.`c1`) and (`test`.`t1`.`a2` = `<subquery5>`.`c2`))))))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where (<in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery8>`.`b1`) and (`test`.`t1i`.`a2` = `<subquery8>`.`b2`))))) and <in_optimizer>((`test`.`t1i`.`a1`,`test`.`t1i`.`a2`),(`test`.`t1i`.`a1`,`test`.`t1i`.`a2`) in ( <materialize> (select `test`.`t3i`.`c1` AS `c1`,`test`.`t3i`.`c2` AS `c2` from `test`.`t3i` where <in_optimizer>((`test`.`t3i`.`c1`,`test`.`t3i`.`c2`),(`test`.`t3i`.`c1`,`test`.`t3i`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery10>`.`b1`) and (`test`.`t3i`.`c2` = `<subquery10>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `<subquery9>`.`c1`) and (`test`.`t1i`.`a2` = `<subquery9>`.`c2`)))))))
 (select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 where c2 LIKE '%02') or
@@ -409,7 +409,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	DEPENDENT UNION	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where ((`test`.`t1`.`a1` > '0') and (<cache>(`test`.`t1`.`a1`) = `test`.`t1`.`a1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t1`.`a2`)) union select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((`test`.`t2`.`b1` < '9') and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#5`.`b1`) and (`test`.`t3`.`c2` = `SUBQUERY#5`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `SUBQUERY#4`.`c1`) and (`test`.`t1`.`a2` = `SUBQUERY#4`.`c2`))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where ((`test`.`t1`.`a1` > '0') and (<cache>(`test`.`t1`.`a1`) = `test`.`t1`.`a1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t1`.`a2`)) union select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((`test`.`t2`.`b1` < '9') and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),(`test`.`t1`.`a1`,`test`.`t1`.`a2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery5>`.`b1`) and (`test`.`t3`.`c2` = `<subquery5>`.`b2`))))) ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery4>`.`c1`) and (`test`.`t1`.`a2` = `<subquery4>`.`c2`))))))
 select * from t1
 where (a1, a2) in (select * from t1 where a1 > '0' UNION select * from t2 where b1 < '9') and
 (a1, a2) in (select c1, c2 from t3
@@ -432,7 +432,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	DEPENDENT UNION	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`c1` = `test`.`t1`.`a1`) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where ((`test`.`t1`.`a1` > '0') and (<cache>(`test`.`t1`.`a1`) = `test`.`t1`.`a1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t1`.`a2`)) union select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((`test`.`t2`.`b1` < '9') and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `SUBQUERY#5`.`b1`) and (`test`.`t3`.`c2` = `SUBQUERY#5`.`b2`))))) ), <primary_index_lookup>(`test`.`t3`.`c1` in <temporary table> on distinct_key where ((`test`.`t3`.`c1` = `SUBQUERY#4`.`c1`) and (`test`.`t3`.`c2` = `SUBQUERY#4`.`c2`))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`c1` = `test`.`t1`.`a1`) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where ((`test`.`t1`.`a1` > '0') and (<cache>(`test`.`t1`.`a1`) = `test`.`t1`.`a1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t1`.`a2`)) union select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((`test`.`t2`.`b1` < '9') and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t3`.`c1` AS `c1`,`test`.`t3`.`c2` AS `c2` from `test`.`t3` where <in_optimizer>((`test`.`t3`.`c1`,`test`.`t3`.`c2`),(`test`.`t3`.`c1`,`test`.`t3`.`c2`) in ( <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `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` = `<subquery5>`.`b1`) and (`test`.`t3`.`c2` = `<subquery5>`.`b2`))))) ), <primary_index_lookup>(`test`.`t3`.`c1` in <temporary table> on distinct_key where ((`test`.`t3`.`c1` = `<subquery4>`.`c1`) and (`test`.`t3`.`c2` = `<subquery4>`.`c2`))))))
 select * from t1, t3
 where (a1, a2) in (select * from t1 where a1 > '0' UNION select * from t2 where b1 < '9') and
 (c1, c2) in (select c1, c2 from t3
@@ -478,7 +478,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1276	Field or reference 'test.t1.a1' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'test.t1.a2' of SELECT #6 was resolved in SELECT #1
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `SUBQUERY#4`.`c2`)))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t3c`.`c1` AS `c1`,`test`.`t3c`.`c2` AS `c2` from `test`.`t3` `t3c` where (<in_optimizer>((`test`.`t3c`.`c1`,`test`.`t3c`.`c2`),<exists>(<index_lookup>(<cache>(`test`.`t3c`.`c1`) in t2i on it2i3 where (((`test`.`t2i`.`b2` > '0') or (`test`.`t2i`.`b2` = `test`.`t1`.`a2`)) and (<cache>(`test`.`t3c`.`c1`) = `test`.`t2i`.`b1`) and (<cache>(`test`.`t3c`.`c2`) = `test`.`t2i`.`b2`))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t3c`.`c1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t3c`.`c2`)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (<in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where ((<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t2`.`b1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t2`.`b2`)))) and <in_optimizer>((`test`.`t1`.`a1`,`test`.`t1`.`a2`),<exists>(select `test`.`t3c`.`c1` AS `c1`,`test`.`t3c`.`c2` AS `c2` from `test`.`t3` `t3c` where (<in_optimizer>((`test`.`t3c`.`c1`,`test`.`t3c`.`c2`),<exists>(<index_lookup>(<cache>(`test`.`t3c`.`c1`) in t2i on it2i3 where (((`test`.`t2i`.`b2` > '0') or (`test`.`t2i`.`b2` = `test`.`t1`.`a2`)) and (<cache>(`test`.`t3c`.`c1`) = `test`.`t2i`.`b1`) and (<cache>(`test`.`t3c`.`c2`) = `test`.`t2i`.`b2`))))) and (<cache>(`test`.`t1`.`a1`) = `test`.`t3c`.`c1`) and (<cache>(`test`.`t1`.`a2`) = `test`.`t3c`.`c2`)))))
 explain extended
 select * from t1 where (a1, a2) in (select '1 - 01', '2 - 01');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -612,7 +612,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
-Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` where <in_optimizer>(`test`.`t1_16`.`a1`,`test`.`t1_16`.`a1` in ( <materialize> (select substr(`test`.`t2_16`.`b1`,1,16) AS `substring(b1,1,16)` from `test`.`t2_16` where (`test`.`t2_16`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1_16`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_16`.`a1` = `SUBQUERY#2`.`substring(b1,1,16)`)))))
+Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` where <in_optimizer>(`test`.`t1_16`.`a1`,`test`.`t1_16`.`a1` in ( <materialize> (select substr(`test`.`t2_16`.`b1`,1,16) AS `substring(b1,1,16)` from `test`.`t2_16` where (`test`.`t2_16`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1_16`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_16`.`a1` = `<subquery2>`.`substring(b1,1,16)`)))))
 select left(a1,7), left(a2,7)
 from t1_16
 where a1 in (select substring(b1,1,16) from t2_16 where b1 > '0');
@@ -641,7 +641,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` where <in_optimizer>(`test`.`t1_16`.`a1`,`test`.`t1_16`.`a1` in ( <materialize> (select group_concat(`test`.`t2_16`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_16` group by `test`.`t2_16`.`b2` ), <primary_index_lookup>(`test`.`t1_16`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_16`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` where <in_optimizer>(`test`.`t1_16`.`a1`,`test`.`t1_16`.`a1` in ( <materialize> (select group_concat(`test`.`t2_16`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_16` group by `test`.`t2_16`.`b2` ), <primary_index_lookup>(`test`.`t1_16`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_16`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_16
 where a1 in (select group_concat(b1) from t2_16 group by b2);
@@ -663,7 +663,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer
 4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(concat(`test`.`t1`.`a1`,'x'),<exists>(select 1 AS `Not_used` from `test`.`t1_16` where (<in_optimizer>((`test`.`t1_16`.`a1`,`test`.`t1_16`.`a2`),<exists>(select `test`.`t2_16`.`b1` AS `b1`,`test`.`t2_16`.`b2` AS `b2` from `test`.`t2_16` join `test`.`t2` where ((`test`.`t2`.`b2` = substr(`test`.`t2_16`.`b2`,1,6)) and <in_optimizer>(`test`.`t2`.`b1`,`test`.`t2`.`b1` in ( <materialize> (select `test`.`t3`.`c1` AS `c1` from `test`.`t3` where (`test`.`t3`.`c2` > '0') ), <primary_index_lookup>(`test`.`t2`.`b1` in <temporary table> on distinct_key where ((`test`.`t2`.`b1` = `SUBQUERY#4`.`c1`))))) and (<cache>(`test`.`t1_16`.`a1`) = `test`.`t2_16`.`b1`) and (<cache>(`test`.`t1_16`.`a2`) = `test`.`t2_16`.`b2`)))) and (<cache>(concat(`test`.`t1`.`a1`,'x')) = left(`test`.`t1_16`.`a1`,8)))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(concat(`test`.`t1`.`a1`,'x'),<exists>(select 1 AS `Not_used` from `test`.`t1_16` where (<in_optimizer>((`test`.`t1_16`.`a1`,`test`.`t1_16`.`a2`),<exists>(select `test`.`t2_16`.`b1` AS `b1`,`test`.`t2_16`.`b2` AS `b2` from `test`.`t2_16` join `test`.`t2` where ((`test`.`t2`.`b2` = substr(`test`.`t2_16`.`b2`,1,6)) and <in_optimizer>(`test`.`t2`.`b1`,`test`.`t2`.`b1` in ( <materialize> (select `test`.`t3`.`c1` AS `c1` from `test`.`t3` where (`test`.`t3`.`c2` > '0') ), <primary_index_lookup>(`test`.`t2`.`b1` in <temporary table> on distinct_key where ((`test`.`t2`.`b1` = `<subquery4>`.`c1`))))) and (<cache>(`test`.`t1_16`.`a1`) = `test`.`t2_16`.`b1`) and (<cache>(`test`.`t1_16`.`a2`) = `test`.`t2_16`.`b2`)))) and (<cache>(concat(`test`.`t1`.`a1`,'x')) = left(`test`.`t1_16`.`a1`,8)))))
 drop table t1_16, t2_16, t3_16;
 set @blob_len = 512;
 set @suffix_len = @blob_len - @prefix_len;
@@ -725,7 +725,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
-Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select substr(`test`.`t2_512`.`b1`,1,512) AS `substring(b1,1,512)` from `test`.`t2_512` where (`test`.`t2_512`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `SUBQUERY#2`.`substring(b1,1,512)`)))))
+Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select substr(`test`.`t2_512`.`b1`,1,512) AS `substring(b1,1,512)` from `test`.`t2_512` where (`test`.`t2_512`.`b1` > '0') ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `<subquery2>`.`substring(b1,1,512)`)))))
 select left(a1,7), left(a2,7)
 from t1_512
 where a1 in (select substring(b1,1,512) from t2_512 where b1 > '0');
@@ -739,7 +739,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2` ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2` ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
@@ -752,7 +752,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2` ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` where <in_optimizer>(`test`.`t1_512`.`a1`,`test`.`t1_512`.`a1` in ( <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2` ), <primary_index_lookup>(`test`.`t1_512`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_512`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
@@ -832,7 +832,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1024` where <in_optimizer>(`test`.`t1_1024`.`a1`,`test`.`t1_1024`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2` ), <primary_index_lookup>(`test`.`t1_1024`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1024`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1024` where <in_optimizer>(`test`.`t1_1024`.`a1`,`test`.`t1_1024`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2` ), <primary_index_lookup>(`test`.`t1_1024`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1024`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
@@ -845,7 +845,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1024` where <in_optimizer>(`test`.`t1_1024`.`a1`,`test`.`t1_1024`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2` ), <primary_index_lookup>(`test`.`t1_1024`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1024`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1024` where <in_optimizer>(`test`.`t1_1024`.`a1`,`test`.`t1_1024`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2` ), <primary_index_lookup>(`test`.`t1_1024`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1024`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
@@ -925,7 +925,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1025` where <in_optimizer>(`test`.`t1_1025`.`a1`,`test`.`t1_1025`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2` ), <primary_index_lookup>(`test`.`t1_1025`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1025`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1025` where <in_optimizer>(`test`.`t1_1025`.`a1`,`test`.`t1_1025`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2` ), <primary_index_lookup>(`test`.`t1_1025`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1025`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
@@ -938,7 +938,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1025` where <in_optimizer>(`test`.`t1_1025`.`a1`,`test`.`t1_1025`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2` ), <primary_index_lookup>(`test`.`t1_1025`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1025`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)))))
+Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1025` where <in_optimizer>(`test`.`t1_1025`.`a1`,`test`.`t1_1025`.`a1` in ( <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2` ), <primary_index_lookup>(`test`.`t1_1025`.`a1` in <temporary table> on distinct_key where ((`test`.`t1_1025`.`a1` = `<subquery2>`.`group_concat(b1)`)))))
 select left(a1,7), left(a2,7)
 from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
@@ -959,7 +959,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1bit	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2bit	ALL	NULL	NULL	NULL	NULL	3	100.00	
 Warnings:
-Note	1003	select conv(`test`.`t1bit`.`a1`,10,2) AS `bin(a1)`,conv(`test`.`t1bit`.`a2`,10,2) AS `bin(a2)` from `test`.`t1bit` where <in_optimizer>((`test`.`t1bit`.`a1`,`test`.`t1bit`.`a2`),(`test`.`t1bit`.`a1`,`test`.`t1bit`.`a2`) in ( <materialize> (select `test`.`t2bit`.`b1` AS `b1`,`test`.`t2bit`.`b2` AS `b2` from `test`.`t2bit` ), <primary_index_lookup>(`test`.`t1bit`.`a1` in <temporary table> on distinct_key where ((`test`.`t1bit`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t1bit`.`a2` = `SUBQUERY#2`.`b2`)))))
+Note	1003	select conv(`test`.`t1bit`.`a1`,10,2) AS `bin(a1)`,conv(`test`.`t1bit`.`a2`,10,2) AS `bin(a2)` from `test`.`t1bit` where <in_optimizer>((`test`.`t1bit`.`a1`,`test`.`t1bit`.`a2`),(`test`.`t1bit`.`a1`,`test`.`t1bit`.`a2`) in ( <materialize> (select `test`.`t2bit`.`b1` AS `b1`,`test`.`t2bit`.`b2` AS `b2` from `test`.`t2bit` ), <primary_index_lookup>(`test`.`t1bit`.`a1` in <temporary table> on distinct_key where ((`test`.`t1bit`.`a1` = `<subquery2>`.`b1`) and (`test`.`t1bit`.`a2` = `<subquery2>`.`b2`)))))
 select bin(a1), bin(a2)
 from t1bit
 where (a1, a2) in (select b1, b2 from t2bit);
@@ -1030,7 +1030,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 where a in (select c from t2 where d >= 20);
 a
 2
@@ -1044,7 +1044,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using where; Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 where a in (select c from t2 where d >= 20);
 a
 2
@@ -1058,7 +1058,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using where; Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 where a in (select c from t2 where d >= 20);
 a
 2
@@ -1071,7 +1071,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 group by a having a in (select c from t2 where d >= 20);
 a
 2
@@ -1083,7 +1083,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 group by a having a in (select c from t2 where d >= 20);
 a
 2
@@ -1200,7 +1200,7 @@ 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	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	
+1	PRIMARY	<subquery2>	ALL	unique_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);
@@ -1224,7 +1224,7 @@ 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	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_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

mysql-test/r/subselect_no_semijoin.result

@@ -1302,7 +1302,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
 2
@@ -1312,7 +1312,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
@@ -1323,7 +1323,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	index	PRIMARY	PRIMARY	4	NULL	3	100.00	Using index
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`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));
@@ -1345,7 +1345,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t1	index	NULL	a	10	NULL	10004	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
 2
@@ -1355,7 +1355,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t1	index	NULL	a	10	NULL	10004	100.00	Using where; Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
@@ -1366,7 +1366,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	index	a	a	5	NULL	3	100.00	Using index
 2	SUBQUERY	t1	index	NULL	a	10	NULL	10004	100.00	Using where; Using index; Using join buffer
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 insert into t1 values (3,31);
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
@@ -1382,7 +1382,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t1	index	NULL	a	10	NULL	10005	100.00	Using where; Using index
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `SUBQUERY#2`.`a`)))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`b` <> 30) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `<subquery2>`.`a`)))))
 drop table t0, t1, t2, t3;
 create table t1 (a int, b int);
 create table t2 (a int, b int);
@@ -2836,7 +2836,7 @@ 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	Using where
 2	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` where <in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),(`test`.`t1`.`one`,`test`.`t1`.`two`) in ( <materialize> (select `test`.`t2`.`one` AS `one`,`test`.`t2`.`two` AS `two` from `test`.`t2` where (`test`.`t2`.`flag` = 'N') ), <primary_index_lookup>(`test`.`t1`.`one` in <temporary table> on distinct_key where ((`test`.`t1`.`one` = `SUBQUERY#2`.`one`) and (`test`.`t1`.`two` = `SUBQUERY#2`.`two`)))))
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` where <in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),(`test`.`t1`.`one`,`test`.`t1`.`two`) in ( <materialize> (select `test`.`t2`.`one` AS `one`,`test`.`t2`.`two` AS `two` from `test`.`t2` where (`test`.`t2`.`flag` = 'N') ), <primary_index_lookup>(`test`.`t1`.`one` in <temporary table> on distinct_key where ((`test`.`t1`.`one` = `<subquery2>`.`one`) and (`test`.`t1`.`two` = `<subquery2>`.`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	
@@ -4329,13 +4329,13 @@ 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
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,1 in ( <materialize> (select 1 AS `1` from `test`.`t1` group by `test`.`t1`.`a` ), <primary_index_lookup>(1 in <temporary table> on distinct_key where ((1 = `SUBQUERY#2`.`1`)))))
+Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,1 in ( <materialize> (select 1 AS `1` from `test`.`t1` group by `test`.`t1`.`a` ), <primary_index_lookup>(1 in <temporary table> on distinct_key where ((1 = `<subquery2>`.`1`)))))
 EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 WHERE a > 3 GROUP BY a);
 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
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,1 in ( <materialize> (select 1 AS `1` from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` ), <primary_index_lookup>(1 in <temporary table> on distinct_key where ((1 = `SUBQUERY#2`.`1`)))))
+Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,1 in ( <materialize> (select 1 AS `1` from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` ), <primary_index_lookup>(1 in <temporary table> on distinct_key where ((1 = `<subquery2>`.`1`)))))
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.

mysql-test/r/subselect_sj.result

@@ -848,7 +848,7 @@ INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii','iiii','ffff','ffff','ffff','f
 EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	13	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	13	func	1	1.00	
 2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Using MRR
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
@@ -1017,7 +1017,7 @@ FROM t1
 WHERE `varchar_nokey`  < 'n' XOR `pk`  )   ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	18	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	8	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	8	func	1	1.00	
 2	SUBQUERY	t1	ALL	varchar_key	NULL	NULL	NULL	15	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key`) and ((`test`.`t1`.`varchar_nokey` < 'n') xor `test`.`t1`.`pk`))

mysql-test/r/subselect_sj2.result

@@ -32,7 +32,7 @@ a	b
 9	5
 explain select * from t2 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	3	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ref	b	b	5	test.t1.a	2	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
 select * from t2 where b in (select a from t1);
@@ -74,7 +74,7 @@ A.a + 10*B.a, A.a + 10*B.a, A.a + 10*B.a, A.a + 10*B.a
 from t0 A, t0 B where B.a <5;
 explain select * from t3 where b in (select a from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	b	b	5	test.t0.a	1	
 2	SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	
 set @save_ecp= @@engine_condition_pushdown;
@@ -101,7 +101,7 @@ set max_heap_table_size= @save_max_heap_table_size;
 explain select * from t1 where a in (select b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	t2	index	b	b	5	NULL	10	Using index
 select * from t1;
 a	b
@@ -129,7 +129,7 @@ explain select
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	22	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
@@ -163,7 +163,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -197,7 +197,7 @@ explain select
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	22	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
@@ -231,7 +231,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -348,7 +348,7 @@ WHERE t1.Code IN (
 SELECT t2.CountryCode FROM t2 WHERE Population > 5000000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	31	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
 SELECT Name FROM t1 
 WHERE t1.Code IN (
@@ -696,7 +696,7 @@ The following must use loose index scan over t3, key a:
 explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)

mysql-test/r/subselect_sj2_jcl6.result

@@ -36,7 +36,7 @@ a	b
 9	5
 explain select * from t2 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	3	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ref	b	b	5	test.t1.a	2	Using join buffer
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
 select * from t2 where b in (select a from t1);
@@ -78,7 +78,7 @@ A.a + 10*B.a, A.a + 10*B.a, A.a + 10*B.a, A.a + 10*B.a
 from t0 A, t0 B where B.a <5;
 explain select * from t3 where b in (select a from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	10	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	b	b	5	test.t0.a	1	Using join buffer
 2	SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	
 set @save_ecp= @@engine_condition_pushdown;
@@ -105,7 +105,7 @@ set max_heap_table_size= @save_max_heap_table_size;
 explain select * from t1 where a in (select b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	t2	index	b	b	5	NULL	10	Using index
 select * from t1;
 a	b
@@ -133,7 +133,7 @@ explain select
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	22	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
@@ -167,7 +167,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -201,7 +201,7 @@ explain select
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	22	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
@@ -235,7 +235,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2)
 from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
@@ -352,7 +352,7 @@ WHERE t1.Code IN (
 SELECT t2.CountryCode FROM t2 WHERE Population > 5000000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	31	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
 SELECT Name FROM t1 
 WHERE t1.Code IN (
@@ -702,7 +702,7 @@ The following must use loose index scan over t3, key a:
 explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	5	func	1	
 2	SUBQUERY	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)

mysql-test/r/subselect_sj_jcl6.result

@@ -852,7 +852,7 @@ INSERT INTO t2 VALUES (1,'i','iiii','iiii','iiii','iiii','ffff','ffff','ffff','f
 EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	13	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	13	func	1	1.00	
 2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Using MRR
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
@@ -1021,7 +1021,7 @@ FROM t1
 WHERE `varchar_nokey`  < 'n' XOR `pk`  )   ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	18	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	8	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	8	func	1	1.00	
 2	SUBQUERY	t1	ALL	varchar_key	NULL	NULL	NULL	15	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t2`.`varchar_nokey` AS `varchar_nokey` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`varchar_nokey` = `test`.`t1`.`varchar_key`) and ((`test`.`t1`.`varchar_nokey` < 'n') xor `test`.`t1`.`pk`))

mysql-test/r/subselect_sj_mat.result

@@ -39,7 +39,7 @@ explain extended
 select * from t1 where a1 in (select b1 from t2 where b1 > '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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	9	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	9	func	1	1.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`b1` > '0'))
@@ -51,10 +51,10 @@ explain extended
 select * from t1 where a1 in (select b1 from t2 where b1 > '0' group by b1);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	9	test.t1.a1	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	test.t1.a1	1	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`) join `test`.`t1` where (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`)
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`) join `test`.`t1` where (`<subquery2>`.`b1` = `test`.`t1`.`a1`)
 select * from t1 where a1 in (select b1 from t2 where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -63,10 +63,10 @@ explain extended
 select * from t1 where (a1, a2) in (select b1, b2 from t2 where b1 > '0' group by b1, b2);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) join `test`.`t1` where ((`SUBQUERY#2`.`b2` = `test`.`t1`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) join `test`.`t1` where ((`<subquery2>`.`b2` = `test`.`t1`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1`.`a1`))
 select * from t1 where (a1, a2) in (select b1, b2 from t2 where b1 > '0' group by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -75,10 +75,10 @@ explain extended
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using temporary; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,min(`test`.`t2`.`b2`) AS `min(b2)` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`) join `test`.`t1` where ((`SUBQUERY#2`.`min(b2)` = `test`.`t1`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,min(`test`.`t2`.`b2`) AS `min(b2)` from `test`.`t2` where (`test`.`t2`.`b1` > '0') group by `test`.`t2`.`b1`) join `test`.`t1` where ((`<subquery2>`.`min(b2)` = `test`.`t1`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1`.`a1`))
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2 where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -97,11 +97,11 @@ 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	SUBQUERY#2	ALL	distinct_key	#	NULL	#	3	100.00	#
+1	PRIMARY	<subquery2>	ALL	distinct_key	#	NULL	#	3	100.00	#
 1	PRIMARY	t1i	ref	it1i1,it1i3	#	9	#	1	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  <materialize> (select `test`.`t2i`.`b1` AS `b1` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1i` where (`test`.`t1i`.`a1` = `SUBQUERY#2`.`b1`)
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1i` where (`test`.`t1i`.`a1` = `<subquery2>`.`b1`)
 select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -121,10 +121,10 @@ 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	it1i1,it1i2,it1i3	#	#	#	3	100.00	#
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	#	#	#	1	100.00	#
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	#	#	#	1	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  <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`,`test`.`t2i`.`b2`) join `test`.`t1i` where ((`SUBQUERY#2`.`b2` = `test`.`t1i`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1i`.`a1`))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`,`test`.`t2i`.`b2`) join `test`.`t1i` where ((`<subquery2>`.`b2` = `test`.`t1i`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1i`.`a1`))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -133,10 +133,10 @@ 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	it1i1,it1i2,it1i3	#	#	#	3	100.00	#
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	#	#	#	1	100.00	#
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	#	#	#	1	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  <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1i` where ((`SUBQUERY#2`.`min(b2)` = `test`.`t1i`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1i`.`a1`))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1i` where ((`<subquery2>`.`min(b2)` = `test`.`t1i`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1i`.`a1`))
 select * from t1i where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -145,10 +145,10 @@ explain extended
 select * from t1 where (a1, a2) in (select b1, max(b2) from t2i group by b1);
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
 2	SUBQUERY	t2i	range	NULL	it2i3	9	NULL	3	100.00	Using index for group-by
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,max(`test`.`t2i`.`b2`) AS `max(b2)` from `test`.`t2i` group by `test`.`t2i`.`b1`) join `test`.`t1` where ((`SUBQUERY#2`.`max(b2)` = `test`.`t1`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,max(`test`.`t2i`.`b2`) AS `max(b2)` from `test`.`t2i` group by `test`.`t2i`.`b1`) join `test`.`t1` where ((`<subquery2>`.`max(b2)` = `test`.`t1`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1`.`a1`))
 select * from t1 where (a1, a2) in (select b1, max(b2) from t2i group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -157,12 +157,12 @@ prepare st1 from "explain select * from t1 where (a1, a2) in (select b1, max(b2)
 execute st1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	
 2	SUBQUERY	t2i	range	NULL	it2i3	9	NULL	3	Using index for group-by
 execute st1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	
 2	SUBQUERY	t2i	range	NULL	it2i3	9	NULL	3	Using index for group-by
 prepare st2 from "select * from t1 where (a1, a2) in (select b1, max(b2) from t2i group by b1)";
 execute st2;
@@ -177,10 +177,10 @@ explain extended
 select * from t1 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	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
 2	SUBQUERY	t2i	range	it2i1,it2i3	it2i3	18	NULL	3	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1` where ((`SUBQUERY#2`.`min(b2)` = `test`.`t1`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,min(`test`.`t2i`.`b2`) AS `min(b2)` from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1` where ((`<subquery2>`.`min(b2)` = `test`.`t1`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1`.`a1`))
 select * from t1 where (a1, a2) in (select b1, min(b2) from t2i where b1 > '0' group by b1);
 a1	a2
 1 - 01	2 - 01
@@ -219,10 +219,10 @@ 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
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1.a1,test.t1.a2	1	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` order by `test`.`t2`.`b1`,`test`.`t2`.`b2`) join `test`.`t1` where ((`SUBQUERY#2`.`b2` = `test`.`t1`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1`.`a1`))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` order by `test`.`t2`.`b1`,`test`.`t2`.`b2`) join `test`.`t1` where ((`<subquery2>`.`b2` = `test`.`t1`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1`.`a1`))
 select * from t1 where (a1, a2) in (select b1, b2 from t2 order by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -231,10 +231,10 @@ explain extended
 select * from t1i where (a1, a2) in (select b1, b2 from t2i order by b1, b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1i	index	it1i1,it1i2,it1i3	it1i3	18	NULL	3	100.00	Using index
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	18	test.t1i.a1,test.t1i.a2	1	100.00	
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	18	test.t1i.a1,test.t1i.a2	1	100.00	
 2	SUBQUERY	t2i	index	NULL	it2i3	18	NULL	5	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` order by `test`.`t2i`.`b1`,`test`.`t2i`.`b2`) join `test`.`t1i` where ((`SUBQUERY#2`.`b2` = `test`.`t1i`.`a2`) and (`SUBQUERY#2`.`b1` = `test`.`t1i`.`a1`))
+Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select `test`.`t2i`.`b1` AS `b1`,`test`.`t2i`.`b2` AS `b2` from `test`.`t2i` order by `test`.`t2i`.`b1`,`test`.`t2i`.`b2`) join `test`.`t1i` where ((`<subquery2>`.`b2` = `test`.`t1i`.`a2`) and (`<subquery2>`.`b1` = `test`.`t1i`.`a1`))
 select * from t1i where (a1, a2) in (select b1, b2 from t2i order by b1, b2);
 a1	a2
 1 - 01	2 - 01
@@ -285,8 +285,8 @@ where (a1, a2) in (select b1, b2 from t2 where b1 >  '0') and
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	18	func	1	1.00	
-1	PRIMARY	SUBQUERY#3	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery3>	eq_ref	unique_key	unique_key	18	func	1	1.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 3	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	it2i3	18	NULL	5	80.00	Using where; Using index; Using join buffer
@@ -306,8 +306,8 @@ where (a1, a2) in (select b1, b2 from t2i where b1 >  '0') and
 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	it1i1,it1i2,it1i3	#	#	#	3	100.00	#
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	#	#	#	1	1.00	#
-1	PRIMARY	SUBQUERY#3	eq_ref	unique_key	#	#	#	1	1.00	#
+1	PRIMARY	<subquery2>	eq_ref	unique_key	#	#	#	1	1.00	#
+1	PRIMARY	<subquery3>	eq_ref	unique_key	#	#	#	1	1.00	#
 2	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	#	#	#	5	100.00	#
 3	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	#	#	#	5	100.00	#
 3	SUBQUERY	t3i	index	it3i1,it3i2,it3i3	#	#	#	4	75.00	#
@@ -329,15 +329,15 @@ b2 in (select c2 from t3 where c2 LIKE '%03')) and
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	18	func	1	1.00	
-1	PRIMARY	SUBQUERY#5	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery5>	eq_ref	unique_key	unique_key	18	func	1	1.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 5	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 5	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	it2i3	18	NULL	5	80.00	Using where; Using index; Using join buffer
 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
 Warnings:
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3`) where ((`test`.`t2i`.`b2` = `test`.`t3`.`c2`) and (`test`.`t2i`.`b1` = `test`.`t3`.`c1`) and (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#3`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#4`.`c2`)))))) and (`test`.`t3`.`c2` > '0'))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3`) where ((`test`.`t2i`.`b2` = `test`.`t3`.`c2`) and (`test`.`t2i`.`b1` = `test`.`t3`.`c1`) and (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery4>`.`c2`)))))) and (`test`.`t3`.`c2` > '0'))
 select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 where c2 LIKE '%02') or
@@ -356,14 +356,14 @@ 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	Start temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; End temporary; Using join buffer
-1	PRIMARY	SUBQUERY#5	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery5>	eq_ref	unique_key	unique_key	18	func	1	1.00	
 5	SUBQUERY	t3c	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 5	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	it2i3	18	NULL	5	80.00	Using where; Using index; Using join buffer
 4	SUBQUERY	t3b	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 3	DEPENDENT SUBQUERY	t3a	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'test.t1.a1' of SELECT #3 was resolved in SELECT #1
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3` `t3c`) where ((`test`.`t2`.`b2` = `test`.`t1`.`a2`) and (`test`.`t2i`.`b2` = `test`.`t3c`.`c2`) and (`test`.`t2`.`b1` = `test`.`t1`.`a1`) and (`test`.`t2i`.`b1` = `test`.`t3c`.`c1`) and (<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `SUBQUERY#4`.`c2`)))))) and (`test`.`t3c`.`c2` > '0'))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3` `t3c`) where ((`test`.`t2`.`b2` = `test`.`t1`.`a2`) and (`test`.`t2i`.`b2` = `test`.`t3c`.`c2`) and (`test`.`t2`.`b1` = `test`.`t1`.`a1`) and (`test`.`t2i`.`b1` = `test`.`t3c`.`c1`) and (<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))) and (`test`.`t3c`.`c2` > '0'))
 select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 t3a where c1 = a1) or
@@ -387,7 +387,7 @@ 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	SUBQUERY#2	ALL	distinct_key	#	#	#	5	0.00	#
+1	PRIMARY	<subquery2>	ALL	distinct_key	#	#	#	5	0.00	#
 1	PRIMARY	t3	ALL	NULL	#	#	#	4	100.00	#
 1	PRIMARY	t1	ALL	NULL	#	#	#	3	100.00	#
 1	PRIMARY	t2i	ref	it2i1,it2i2,it2i3	#	#	#	2	100.00	#
@@ -395,14 +395,14 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 4	SUBQUERY	t3	ALL	NULL	#	#	#	4	100.00	#
 3	SUBQUERY	t3	ALL	NULL	#	#	#	4	100.00	#
 7	UNION	t1i	index	it1i1,it1i2,it1i3	#	#	#	3	100.00	#
-7	UNION	SUBQUERY#8	eq_ref	unique_key	#	#	#	1	1.00	#
-7	UNION	SUBQUERY#9	eq_ref	unique_key	#	#	#	1	1.00	#
+7	UNION	<subquery8>	eq_ref	unique_key	#	#	#	1	1.00	#
+7	UNION	<subquery9>	eq_ref	unique_key	#	#	#	1	1.00	#
 8	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	#	#	#	5	100.00	#
 9	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	#	#	#	5	100.00	#
 9	SUBQUERY	t3i	index	it3i1,it3i2,it3i3	#	#	#	4	75.00	#
 NULL	UNION RESULT	<union1,7>	ALL	NULL	#	#	#	NULL	NULL	#
 Warnings:
-Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#3`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `SUBQUERY#4`.`c2`)))))) group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) semi join (`test`.`t2i` join `test`.`t3`) join `test`.`t1` where ((`test`.`t3`.`c2` = `SUBQUERY#2`.`b2`) and (`test`.`t1`.`a2` = `SUBQUERY#2`.`b2`) and (`test`.`t2i`.`b2` = `SUBQUERY#2`.`b2`) and (`test`.`t3`.`c1` = `SUBQUERY#2`.`b1`) and (`test`.`t1`.`a1` = `SUBQUERY#2`.`b1`) and (`test`.`t2i`.`b1` = `SUBQUERY#2`.`b1`) and (`SUBQUERY#2`.`b2` > '0'))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t3i`.`c2` = `test`.`t2i`.`b2`) and (`test`.`t3i`.`c1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t2i`.`b2` > '0')))
+Note	1003	(select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from  <materialize> (select `test`.`t2`.`b1` AS `b1`,`test`.`t2`.`b2` AS `b2` from `test`.`t2` where (<in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery3>`.`c2`))))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3`.`c2` AS `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` = `<subquery4>`.`c2`)))))) group by `test`.`t2`.`b1`,`test`.`t2`.`b2`) semi join (`test`.`t2i` join `test`.`t3`) join `test`.`t1` where ((`test`.`t3`.`c2` = `<subquery2>`.`b2`) and (`test`.`t1`.`a2` = `<subquery2>`.`b2`) and (`test`.`t2i`.`b2` = `<subquery2>`.`b2`) and (`test`.`t3`.`c1` = `<subquery2>`.`b1`) and (`test`.`t1`.`a1` = `<subquery2>`.`b1`) and (`test`.`t2i`.`b1` = `<subquery2>`.`b1`) and (`<subquery2>`.`b2` > '0'))) union (select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` semi join (`test`.`t2i`) semi join (`test`.`t2i` join `test`.`t3i`) where ((`test`.`t3i`.`c2` = `test`.`t2i`.`b2`) and (`test`.`t3i`.`c1` = `test`.`t2i`.`b1`) and (`test`.`t2i`.`b1` > '0') and (`test`.`t2i`.`b2` > '0')))
 (select * from t1
 where (a1, a2) in (select b1, b2 from t2
 where b2 in (select c2 from t3 where c2 LIKE '%02') or
@@ -425,7 +425,7 @@ where (a1, a2) in (select * from t1 where a1 > '0' UNION select * from t2 where
 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
-1	PRIMARY	SUBQUERY#4	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery4>	eq_ref	unique_key	unique_key	18	func	1	1.00	
 4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 4	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	it2i3	18	NULL	5	80.00	Using where; Using index; Using join buffer
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
@@ -449,7 +449,7 @@ a1 = c1;
 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
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer
-1	PRIMARY	SUBQUERY#4	eq_ref	unique_key	unique_key	18	func	1	1.00	
+1	PRIMARY	<subquery4>	eq_ref	unique_key	unique_key	18	func	1	1.00	
 4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 4	SUBQUERY	t2i	index	it2i1,it2i2,it2i3	it2i3	18	NULL	5	80.00	Using where; Using index; Using join buffer
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
@@ -502,7 +502,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1276	Field or reference 'test.t1.a1' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'test.t1.a2' of SELECT #6 was resolved in SELECT #1
-Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3` `t3c`) where ((`test`.`t2i`.`b2` = `test`.`t1`.`a2`) and (`test`.`t3c`.`c2` = `test`.`t1`.`a2`) and (`test`.`t2`.`b2` = `test`.`t1`.`a2`) and (`test`.`t2i`.`b1` = `test`.`t1`.`a1`) and (`test`.`t3c`.`c1` = `test`.`t1`.`a1`) and (`test`.`t2`.`b1` = `test`.`t1`.`a1`) and (<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `SUBQUERY#4`.`c2`)))))))
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` semi join (`test`.`t2`) semi join (`test`.`t2i` join `test`.`t3` `t3c`) where ((`test`.`t2i`.`b2` = `test`.`t1`.`a2`) and (`test`.`t3c`.`c2` = `test`.`t1`.`a2`) and (`test`.`t2`.`b2` = `test`.`t1`.`a2`) and (`test`.`t2i`.`b1` = `test`.`t1`.`a1`) and (`test`.`t3c`.`c1` = `test`.`t1`.`a1`) and (`test`.`t2`.`b1` = `test`.`t1`.`a1`) and (<in_optimizer>(`test`.`t2`.`b2`,<exists>(select 1 AS `Not_used` from `test`.`t3` `t3a` where ((`test`.`t3a`.`c1` = `test`.`t1`.`a1`) and (<cache>(`test`.`t2`.`b2`) = `test`.`t3a`.`c2`)))) or <in_optimizer>(`test`.`t2`.`b2`,`test`.`t2`.`b2` in ( <materialize> (select `test`.`t3b`.`c2` AS `c2` from `test`.`t3` `t3b` where (`test`.`t3b`.`c2` like '%03') ), <primary_index_lookup>(`test`.`t2`.`b2` in <temporary table> on distinct_key where ((`test`.`t2`.`b2` = `<subquery4>`.`c2`)))))))
 explain extended
 select * from t1 where (a1, a2) in (select '1 - 01', '2 - 01');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -634,7 +634,7 @@ from t1_16
 where a1 in (select substring(b1,1,16) from t2_16 where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_16	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	20	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	20	func	1	1.00	
 2	SUBQUERY	t2_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
 Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from `test`.`t1_16` semi join (`test`.`t2_16`) where ((`test`.`t2_16`.`b1` > '0') and (`test`.`t1_16`.`a1` = substr(`test`.`t2_16`.`b1`,1,16)))
@@ -664,10 +664,10 @@ from t1_16
 where a1 in (select group_concat(b1) from t2_16 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_16	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_16.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_16.a1	1	100.00	Using where
 2	SUBQUERY	t2_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_16`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_16` group by `test`.`t2_16`.`b2`) join `test`.`t1_16` where (`test`.`t1_16`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_16`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_16`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_16`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_16` group by `test`.`t2_16`.`b2`) join `test`.`t1_16` where (`test`.`t1_16`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_16
 where a1 in (select group_concat(b1) from t2_16 group by b2);
@@ -749,7 +749,7 @@ from t1_512
 where a1 in (select substring(b1,1,512) from t2_512 where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	517	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	517	func	1	1.00	
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
 Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from `test`.`t1_512` semi join (`test`.`t2_512`) where ((`test`.`t2_512`.`b1` > '0') and (`test`.`t1_512`.`a1` = substr(`test`.`t2_512`.`b1`,1,512)))
@@ -764,10 +764,10 @@ from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_512.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_512.a1	1	100.00	Using where
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2`) join `test`.`t1_512` where (`test`.`t1_512`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2`) join `test`.`t1_512` where (`test`.`t1_512`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
@@ -778,10 +778,10 @@ from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_512	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_512.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_512.a1	1	100.00	Using where
 2	SUBQUERY	t2_512	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2`) join `test`.`t1_512` where (`test`.`t1_512`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_512`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_512`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_512`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_512` group by `test`.`t2_512`.`b2`) join `test`.`t1_512` where (`test`.`t1_512`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_512
 where a1 in (select group_concat(b1) from t2_512 group by b2);
@@ -845,7 +845,7 @@ from t1_1024
 where a1 in (select substring(b1,1,1024) from t2_1024 where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	15	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	15	func	1	1.00	
 2	SUBQUERY	t2_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
 Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1024` semi join (`test`.`t2_1024`) where ((`test`.`t2_1024`.`b1` > '0') and (`test`.`t1_1024`.`a1` = substr(`test`.`t2_1024`.`b1`,1,1024)))
@@ -858,10 +858,10 @@ from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_1024.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_1024.a1	1	100.00	Using where
 2	SUBQUERY	t2_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2`) join `test`.`t1_1024` where (`test`.`t1_1024`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2`) join `test`.`t1_1024` where (`test`.`t1_1024`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
@@ -872,10 +872,10 @@ from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_1024.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_1024.a1	1	100.00	Using where
 2	SUBQUERY	t2_1024	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2`) join `test`.`t1_1024` where (`test`.`t1_1024`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_1024`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1024`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1024`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1024` group by `test`.`t2_1024`.`b2`) join `test`.`t1_1024` where (`test`.`t1_1024`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_1024
 where a1 in (select group_concat(b1) from t2_1024 group by b2);
@@ -939,7 +939,7 @@ from t1_1025
 where a1 in (select substring(b1,1,1025) from t2_1025 where b1 > '0');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	15	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	15	func	1	1.00	
 2	SUBQUERY	t2_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
 Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from `test`.`t1_1025` semi join (`test`.`t2_1025`) where ((`test`.`t2_1025`.`b1` > '0') and (`test`.`t1_1025`.`a1` = substr(`test`.`t2_1025`.`b1`,1,1025)))
@@ -952,10 +952,10 @@ from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_1025.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_1025.a1	1	100.00	Using where
 2	SUBQUERY	t2_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2`) join `test`.`t1_1025` where (`test`.`t1_1025`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2`) join `test`.`t1_1025` where (`test`.`t1_1025`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
@@ -966,10 +966,10 @@ from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	distinct_key	distinct_key	261	test.t1_1025.a1	1	100.00	Using where
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	261	test.t1_1025.a1	1	100.00	Using where
 2	SUBQUERY	t2_1025	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
 Warnings:
-Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2`) join `test`.`t1_1025` where (`test`.`t1_1025`.`a1` = `SUBQUERY#2`.`group_concat(b1)`)
+Note	1003	select left(`test`.`t1_1025`.`a1`,7) AS `left(a1,7)`,left(`test`.`t1_1025`.`a2`,7) AS `left(a2,7)` from  <materialize> (select group_concat(`test`.`t2_1025`.`b1` separator ',') AS `group_concat(b1)` from `test`.`t2_1025` group by `test`.`t2_1025`.`b2`) join `test`.`t1_1025` where (`test`.`t1_1025`.`a1` = `<subquery2>`.`group_concat(b1)`)
 select left(a1,7), left(a2,7)
 from t1_1025
 where a1 in (select group_concat(b1) from t2_1025 group by b2);
@@ -988,7 +988,7 @@ from t1bit
 where (a1, a2) in (select b1, b2 from t2bit);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1bit	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	10	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	10	func	1	1.00	
 2	SUBQUERY	t2bit	ALL	NULL	NULL	NULL	NULL	3	100.00	
 Warnings:
 Note	1003	select conv(`test`.`t1bit`.`a1`,10,2) AS `bin(a1)`,conv(`test`.`t1bit`.`a2`,10,2) AS `bin(a2)` from `test`.`t1bit` semi join (`test`.`t2bit`) where 1
@@ -1059,7 +1059,7 @@ insert into t3 values (30);
 explain extended
 select a from t1 where a in (select c from t2 where d >= 20);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	6	1.00	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	6	1.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where; Using join buffer
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
 Warnings:
@@ -1074,7 +1074,7 @@ create index it1a on t1(a);
 explain extended
 select a from t1 where a in (select c from t2 where d >= 20);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	6	1.00	
+1	PRIMARY	<subquery2>	ALL	unique_key	NULL	NULL	NULL	6	1.00	
 1	PRIMARY	t1	ref	it1a	it1a	4	test.t2.c	2	100.00	Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
 Warnings:
@@ -1090,7 +1090,7 @@ explain extended
 select a from t1 where a in (select c from t2 where d >= 20);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	it1a	it1a	4	NULL	7	100.00	Using index
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	4	func	1	1.00	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	4	func	1	1.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`d` >= 20))
@@ -1106,7 +1106,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 group by a having a in (select c from t2 where d >= 20);
 a
 2
@@ -1118,7 +1118,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	it1a	4	NULL	7	100.00	Using index
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `SUBQUERY#2`.`c`)))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a` having <in_optimizer>(`test`.`t1`.`a`,`test`.`t1`.`a` in ( <materialize> (select `test`.`t2`.`c` AS `c` from `test`.`t2` where (`test`.`t2`.`d` >= 20) ), <primary_index_lookup>(`test`.`t1`.`a` in <temporary table> on distinct_key where ((`test`.`t1`.`a` = `<subquery2>`.`c`)))))
 select a from t1 group by a having a in (select c from t2 where d >= 20);
 a
 2
@@ -1174,7 +1174,7 @@ insert into t1 values (5);
 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	t1	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	SUBQUERY#2	const	distinct_key	distinct_key	5	const	1	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
 min(a1)
@@ -1217,7 +1217,7 @@ insert into t1 values ('aa', 'aaaa');
 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	
-1	PRIMARY	SUBQUERY#2	eq_ref	unique_key	unique_key	3	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 select a,b from t1 where b in (select a from t1);
 a	b
@@ -1238,7 +1238,7 @@ 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	SUBQUERY#2	ALL	unique_key	NULL	NULL	NULL	2	
+1	PRIMARY	<subquery2>	ALL	unique_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);
@@ -1262,7 +1262,7 @@ 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	SUBQUERY#2	eq_ref	unique_key	unique_key	5	func	1	
+1	PRIMARY	<subquery2>	eq_ref	unique_key	unique_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

sql/item_subselect.cc

@@ -3710,7 +3710,7 @@ bool subselect_hash_sj_engine::init_permanent(List<Item> *tmp_columns,
   }
 */
   char buf[32];
-  uint len= my_snprintf(buf, sizeof(buf), "SUBQUERY#%d", subquery_id);
+  uint len= my_snprintf(buf, sizeof(buf), "<subquery%d>", subquery_id);
   char *name;
   if (!(name= (char*)thd->alloc(len + 1)))
     DBUG_RETURN(TRUE);

sql/opt_subselect.cc

@@ -16,6 +16,136 @@
 
 #include <my_bit.h>
 
+/*
+  This file contains optimizations for semi-join subqueries.
+  
+  Contents
+  --------
+  1. What is a semi-join subquery
+  2. General idea about semi-join execution
+  2.1 Correlated vs uncorrelated semi-joins
+  2.2 Mergeable vs non-mergeable semi-joins
+  3. Code-level view of semi-join processing
+  3.1 Conversion
+  3.1.1 Merged semi-join TABLE_LIST object
+  3.1.2 Non-merged semi-join data structure
+  3.2 Semi-joins and query optimization
+  3.3 Semi-joins and query execution
+
+  1. What is a semi-join subquery
+  -------------------------------
+  We use this definition of semi-join:
+
+    outer_tbl SEMI JOIN inner_tbl ON cond = {set of outer_tbl.row such that
+                                             exist inner_tbl.row, for which 
+                                             cond(outer_tbl.row,inner_tbl.row)
+                                             is satisfied}
+  
+  That is, semi-join operation is similar to inner join operation, with
+  exception that we don't care how many matches a row from outer_tbl has in
+  inner_tbl.
+
+  In SQL, that translates into following: a semi-join subquery is an IN 
+  subquery that is an AND-part of the WHERE/ON clause.
+
+  2. General idea about semi-join execution
+  -----------------------------------------
+  We can execute semi-join in a way similar to inner join, with exception that 
+  we need to somehow ensure that we do not generate record combinations that 
+  differ only in rows of inner tables.
+  There is a number of different ways to achieve this property, implemented by
+  a number of semi-join execution strategies.
+  Some strategies can handle any semi-joins, other can be applied only to
+  semi-joins that have certain properties that are described below:
+
+  2.1 Correlated vs uncorrelated semi-joins
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  Uncorrelated semi-joins are special in the respect that they allow to
+   - execute the subquery (possible as it's uncorrelated)
+   - somehow make sure that generated set does not have duplicates
+   - perform an inner join with outer tables.
+  
+  or, rephrasing in SQL form:
+
+  SELECT ... FROM ot WHERE ot.col IN (SELECT it.col FROM it WHERE uncorr_cond)
+    ->
+  SELECT ... FROM ot JOIN (SELECT DISTINCT it.col FROM it WHERE uncorr_cond)
+
+  2.2 Mergeable vs non-mergeable semi-joins
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  Semi-join operation has some degree of commutability with inner join
+  operation: we can join subquery's tables with ouside table(s) and eliminate
+  duplicate record combination after that:
+
+    ot1 JOIN ot2 SEMI_JOIN{it1,it2} (it1 JOIN it2) ON sjcond(ot2,it*) ->
+              |
+              +-------------------------------+
+                                              v
+    ot1 SEMI_JOIN{it1,it2} (it1 JOIN it2 JOIN ot2) ON sjcond(ot2,it*)
+ 
+  In order for this to work, subquery's top-level operation must be join, and
+  grouping or ordering with limit (grouping or ordering with limit are not
+  commutative with duplicate removal). In other words, the conversion is
+  possible when the subquery doesn't have GROUP BY clause, any aggregate
+  functions*, or ORDER BY ... LIMIT clause.
+
+  Definitions:
+  - Subquery whose top-level operation is a join is called *mergeable semi-join*
+  - All other kinds of semi-join subqueries are considered non-mergeable.
+
+  *- this requirement is actually too strong, but its exceptions are too
+  complicated to be considered here.
+
+  3. Code-level view of semi-join processing
+  ------------------------------------------
+  
+  3.1 Conversion
+  --------------
+  * When doing JOIN::prepare for the subquery, we detect that it can be
+    converted into a semi-join and register it in parent_join->sj_subselects
+
+  * At the start of parent_join->optimize(), the predicate is converted into 
+    a semi-join node. A semi-join node is a TABLE_LIST object that is linked
+    somewhere in parent_join->join_list (either it is just present there, or
+    it is a descendant of some of its members).
+  
+  There are two kinds of semi-joins:
+  - Merged semi-joins
+  - Non-merged semi-joins
+   
+  3.1.1 Merged semi-join TABLE_LIST object
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  Merged semi-join object is a TABLE_LIST that contains a sub-join of 
+  subquery tables and the semi-join ON expression (in this respect it is 
+  ery similar to nested outer join representation)
+  Merged semi-join represents this SQL:
+
+    ... SEMI JOIN (inner_tbl1 JOIN ... JOIN inner_tbl_n) ON sj_on_expr
+  
+  Semi-join objects of this kind have TABLE_LIST::sj_subq_pred set.
+ 
+  3.1.2 Non-merged semi-join data structure
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  Non-merged semi-join object is a leaf TABLE_LIST object that has a subquery
+  that produces rows. It is similar to a base table and represents this SQL:
+    
+    ... SEMI_JOIN (SELECT non_mergeable_select) ON sj_on_expr
+  
+  Subquery items that were converted into semi-joins are removed from the WHERE
+  clause. (They do remain in PS-saved WHERE clause, and they replace themselves
+  with Item_int(1) on subsequent re-executions).
+
+  3.2 Semi-joins and query optimization
+  -------------------------------------
+  Query optimizer operates on semi-join nests.
+
+  3.3 Semi-joins and query execution
+  ----------------------------------
+  * Join executor has hooks for all semi-join strategies.
+    TODO elaborate
+*/
+
+
 static
 bool subquery_types_allow_materialization(Item_in_subselect *in_subs);
 static bool replace_where_subcondition(JOIN *join, Item **expr, 
@@ -1092,7 +1222,7 @@ static bool convert_subq_to_jtbm(JOIN *parent_join,
 
   TABLE_LIST *jtbm;
   char *tbl_alias;
-  const char alias_mask[]="SUBQUERY#%d";
+  const char alias_mask[]="<subquery%d>";
   if (!(tbl_alias= (char*)parent_join->thd->calloc(sizeof(alias_mask)+5)) || 
       !(jtbm= alloc_join_nest(parent_join->thd))) //todo: this is not a join nest!
   {

sql/sql_select.cc

@@ -5899,7 +5899,6 @@ get_best_combination(JOIN *join)
     TABLE *form;
     *j= *join->best_positions[tablenr].table;
     form=join->table[tablenr]=j->table;
- //psergey-merge: or is the above:   form=join->all_tables[tablenr]=j->table;
     used_tables|= form->map;
     form->reginfo.join_tab=j;
     if (!*j->on_expr_ref)
@@ -15052,8 +15051,6 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
 				       &usable_keys)) < MAX_KEY)
       {
 	/* Found key that can be used to retrieve data in sorted order */
-        //psergey-mrr:if (tab->pre_idx_push_select_cond)
-        //  tab->select_cond= tab->select->cond= tab->pre_idx_push_select_cond;
 	if (tab->ref.key >= 0)
 	{
           /*
@@ -17990,7 +17987,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
         /* table */
         int len= my_snprintf(table_name_buffer, 
                              sizeof(table_name_buffer)-1,
-                             "SUBQUERY#%d", 
+                             "<subquery%d>", 
                              tab->emb_sj_nest->sj_subq_pred->get_identifier());
 	item_list.push_back(new Item_string(table_name_buffer, len, cs));
         /* partitions */