Backport of WL#5953 from MySQL 5.6

The patch differs from the original MySQL patch as follows:
- All test case differences have been reviewed one by one, and
  care has been taken to restore the original plan so that each
  test case executes the code path it was designed for.
- A bug was found and fixed in MariaDB 5.3 in
  Item_allany_subselect::cleanup().
- ORDER BY is not removed because we are unsure of all effects,
  and it would prevent enabling ORDER BY ... LIMIT subqueries.
- ref_pointer_array.m_size is not adjusted because we don't do
  array bounds checking, and because it looks risky.

Original comment by Jorgen Loland:
-------------------------------------------------------------
WL#5953 - Optimize away useless subquery clauses
      
For IN/ALL/ANY/SOME/EXISTS subqueries, the following clauses are 
meaningless:
      
* ORDER BY (since we don't support LIMIT in these subqueries)
* DISTINCT
* GROUP BY if there is no HAVING clause and no aggregate 
  functions
      
This WL detects and optimizes away these useless parts of the
query during JOIN::prepare()

mysql-test/include/mix1.inc

@@ -1184,9 +1184,9 @@ DROP TABLE t1;
 create table t1 (a bit(1) not null,b int) engine=myisam;
 create table t2 (c int) engine=innodb;
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
+set @@optimizer_switch='in_to_exists=on,materialization=off';
 explain
-select b from t1 where a not in (select b from t1,t2 group by a) group by a;
+select b from t1 where a not in (select max(b) from t1,t2 group by a) group by a;
 set optimizer_switch=@save_optimizer_switch;
 DROP TABLE t1,t2;
 

mysql-test/r/explain.result

@@ -265,7 +265,7 @@ CREATE TABLE t1(f1 VARCHAR(6) NOT NULL,
 FULLTEXT KEY(f1),UNIQUE(f1));
 INSERT INTO t1 VALUES ('test');
 EXPLAIN SELECT 1 FROM t1
-WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST (""))
+WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST (""))
 WHERE t1.f1 GROUP BY t1.f1));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
@@ -273,7 +273,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
- WHERE 1 > ALL((SELECT 1 FROM t1 RIGHT OUTER JOIN t1 a
+ WHERE 1 > ALL((SELECT t1.f1 FROM t1 RIGHT OUTER JOIN t1 a
  ON (MATCH(t1.f1) AGAINST (""))
  WHERE t1.f1 GROUP BY t1.f1))';
 EXECUTE stmt;
@@ -289,7 +289,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 DEALLOCATE PREPARE stmt;
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
- WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a
+ WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a
  ON (MATCH(t1.f1) AGAINST (""))
  WHERE t1.f1 GROUP BY t1.f1))';
 EXECUTE stmt;

mysql-test/r/fulltext.result

@@ -684,10 +684,8 @@ PREPARE stmt FROM
  WHERE t1.f1 GROUP BY t1.f1))';
 EXECUTE stmt;
 1
-1
 EXECUTE stmt;
 1
-1
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1;
 End of 5.1 tests

mysql-test/r/group_min_max.result

@@ -2963,7 +2963,7 @@ WHERE EXISTS ( SELECT DISTINCT b FROM t1 WHERE b <= alias1.a ) ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	b	5	NULL	10	Using index
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
-3	DEPENDENT SUBQUERY	t1	index	b	b	5	NULL	10	Using where; Using index; Using temporary
+3	DEPENDENT SUBQUERY	t1	index	b	b	5	NULL	10	Using where; Using index
 SELECT alias1.* FROM t1, (SELECT * FROM t1) AS alias1
 WHERE EXISTS ( SELECT DISTINCT b FROM t1 WHERE b <= alias1.a ) ;
 a	b
@@ -3073,7 +3073,7 @@ WHERE EXISTS ( SELECT DISTINCT b FROM t1 WHERE b <= alias1.a ) ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	b	5	NULL	10	Using index
 1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	ALL	b	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t1	index	b	b	5	NULL	10	Using where; Using index
 SELECT alias1.* FROM t1, t1 AS alias1
 WHERE EXISTS ( SELECT DISTINCT b FROM t1 WHERE b <= alias1.a ) ;
 a	b

mysql-test/r/myisam_mrr.result

@@ -350,9 +350,9 @@ GROUP BY t2.pk
 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
-2	SUBQUERY	t2	ref	int_key	int_key	5	const	1	100.00	Using index condition; Using where; Using filesort
+2	SUBQUERY	t2	ref	int_key	int_key	5	const	1	100.00	Using index condition
 Warnings:
-Note	1003	select min(1) AS `MIN(t1.pk)` from `test`.`t1` where exists(select `test`.`t2`.`pk` from `test`.`t2` where isnull(`test`.`t2`.`int_key`) group by `test`.`t2`.`pk`)
+Note	1003	select min(1) AS `MIN(t1.pk)` from `test`.`t1` where exists(select `test`.`t2`.`pk` from `test`.`t2` where isnull(`test`.`t2`.`int_key`))
 DROP TABLE t1, t2;
 #
 # BUG#42048 Discrepancy between MyISAM and Maria's ICP implementation

mysql-test/r/subselect.result

@@ -1662,7 +1662,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select NULL from `test`.`t2` group by 1) > <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(NULL) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1670,7 +1670,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,(<min>(select NULL from `test`.`t2` group by 1) <= <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(NULL) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1686,7 +1686,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1702,7 +1702,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -2980,9 +2980,9 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `tes
 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	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; Using temporary
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') group by `test`.`t2`.`one`,`test`.`t2`.`two` having (trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`))) and trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
 DROP TABLE t1,t2;
 set optimizer_switch=@tmp11867_optimizer_switch;
 CREATE TABLE t1 (a char(5), b char(5));
@@ -4463,20 +4463,20 @@ a
 drop table t1, t2;
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 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);
+Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 1 from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`1` = 1)
+Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.
@@ -4820,8 +4820,6 @@ SELECT * FROM t1
 WHERE EXISTS (SELECT DISTINCT a FROM t2 WHERE t1.a < t2.a ORDER BY b);
 pk	a
 1	10
-3	30
-2	20
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY b (b));
 INSERT INTO t1 VALUES (1,NULL), (9,NULL);
@@ -5246,18 +5244,21 @@ DROP table t1,t2;
 #
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 b
 0
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 #
 # Bug #11765713 58705:
@@ -5653,7 +5654,7 @@ WHERE f1_key != table2.f1_key AND f1_key >= table1.f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t2	ALL	f1_key	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t2	index	f1_key	f1_key	4	NULL	10	Using where; Using index
 DROP TABLE t1,t2;
 #
 # LP bug #826279: assertion failure with GROUP BY a result of subquery
@@ -5881,7 +5882,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
 EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	a	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index	NULL	a	4	NULL	1	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	4	func	2	Using index
 SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 a
 2009-01-01

mysql-test/r/subselect4.result

@@ -706,36 +706,34 @@ INSERT INTO t1 VALUES ('28','6','m'),('29','4','c');
 CREATE TABLE t2 (f11 varchar(1)) ;
 INSERT INTO t2 VALUES ('f'),('d');
 SET @old_optimizer_switch = @@session.optimizer_switch;
-SET SESSION optimizer_switch = 'materialization=on,in_to_exists=off,';
+SET @@optimizer_switch = 'materialization=on,in_to_exists=off,semijoin=off';
 EXPLAIN
 SELECT * FROM t1
 WHERE f3 = (
 SELECT t1.f3 FROM t1
-WHERE ( t1.f10 ) IN ( SELECT f11 FROM t2 GROUP BY f11 ));
+WHERE ( t1.f10 ) IN ( SELECT max(f11) FROM t2 GROUP BY f11 ));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	f3	f3	5	const	0	Using where
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	5	test.t1.f10	1	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using temporary
 SELECT * FROM t1
 WHERE f3 = (
 SELECT t1.f3 FROM t1
-WHERE ( t1.f10 ) IN ( SELECT f11 FROM t2 GROUP BY f11 ));
+WHERE ( t1.f10 ) IN ( SELECT max(f11) FROM t2 GROUP BY f11 ));
 f1	f3	f10
 EXPLAIN
 SELECT * FROM t1
 WHERE f3 = (
 SELECT f3 FROM t1
-WHERE ( f10, f10 ) IN ( SELECT f11, f11 FROM t2 GROUP BY f11 ));
+WHERE ( f10, f10 ) IN ( SELECT max(f11), f11 FROM t2 GROUP BY f11 ));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	f3	f3	5	const	0	Using where
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	10	test.t1.f10,test.t1.f10	1	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using temporary
 SELECT * FROM t1
 WHERE f3 = (
 SELECT f3 FROM t1
-WHERE ( f10, f10 ) IN ( SELECT f11, f11 FROM t2 GROUP BY f11 ));
+WHERE ( f10, f10 ) IN ( SELECT max(f11), f11 FROM t2 GROUP BY f11 ));
 f1	f3	f10
 SET SESSION optimizer_switch = @old_optimizer_switch;
 drop table t1,t2;
@@ -1331,7 +1329,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE
 (SELECT f2 FROM t2
 WHERE f4 <= ALL
-(SELECT SQ1_t1.f4
+(SELECT max(SQ1_t1.f4)
 FROM t3 AS SQ1_t1 JOIN t3 AS SQ1_t3 ON SQ1_t3.f4
 GROUP BY SQ1_t1.f4));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -1624,68 +1622,68 @@ INSERT INTO t2 VALUES
 (10,5,'d1d');
 set @save_optimizer_switch=@@optimizer_switch;
 SET optimizer_switch='outer_join_with_cache=off';
-set @@optimizer_switch = 'materialization=off';
+set @@optimizer_switch = 'in_to_exists=on,materialization=off,semijoin=off';
 EXPLAIN
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	PRIMARY	alias1	index	NULL	PRIMARY	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	2	
+2	DEPENDENT SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	2	Using temporary
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 f1	f2
 8	8
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 f1b	f2b	f3b
 10	5	d1d
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 f1b	f2b	f3b
 10	5	d1d
-SET @@optimizer_switch = 'materialization=on';
+set @@optimizer_switch = 'in_to_exists=off,materialization=on,semijoin=off';
 EXPLAIN
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	PRIMARY	alias1	index	NULL	PRIMARY	4	NULL	2	Using where; Using index
-2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	2	Using temporary
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 f1	f2
 8	8
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 f1b	f2b	f3b
 10	5	d1d
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 f1b	f2b	f3b
 10	5	d1d
 set @@optimizer_switch=@save_optimizer_switch;
@@ -1770,7 +1768,7 @@ FROM t1));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
-3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 drop table t1, t2, t3;
 #
 # LP BUG#802979 Assertion `table->key_read == 0' in close_thread_table
@@ -1793,7 +1791,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	f1	f1	5	const	0	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
-3	SUBQUERY	t4	index	NULL	f1	5	NULL	2	Using index; Using temporary
+3	SUBQUERY	t4	index	NULL	f1	5	NULL	2	Using index
 SELECT *
 FROM t1, t2
 WHERE t2.f2 = (SELECT f2 FROM t3
@@ -1810,7 +1808,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ref	f1	f1	5	const	0	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
-3	SUBQUERY	t4	index	NULL	f1	5	NULL	2	Using index; Using temporary
+3	SUBQUERY	t4	index	NULL	f1	5	NULL	2	Using index
 SELECT *
 FROM t1, t2
 WHERE t2.f2 = (SELECT f2 FROM t3
@@ -1838,7 +1836,7 @@ FROM t1));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	2	
-3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT *
 FROM t2, t3
 WHERE t3.f1 = (
@@ -1884,7 +1882,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	NULL	col_int_key	5	NULL	2	Using index
 2	SUBQUERY	SUBQUERY2_t1	index	NULL	col_int_key	5	NULL	2	Using index
 2	SUBQUERY	SUBQUERY2_t2	ALL	col_varchar_key	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT col_int_key
 FROM t2
 WHERE (SELECT SUBQUERY2_t1.col_int_key
@@ -1906,7 +1904,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	NULL	col_int_key	5	NULL	2	Using index
 2	SUBQUERY	SUBQUERY2_t1	index	NULL	col_int_key	5	NULL	2	Using index
 2	SUBQUERY	SUBQUERY2_t2	ALL	col_varchar_key	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT col_int_key
 FROM t2
 WHERE (SELECT SUBQUERY2_t1.col_int_key

mysql-test/r/subselect_innodb.result

@@ -291,7 +291,7 @@ GROUP BY 1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	1	Using temporary; Using filesort
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	1	
 SELECT MAX( f1 ) FROM t2
 WHERE f2 >= (
 SELECT SUM( f1 )

mysql-test/r/subselect_mat_cost_bugs.result

@@ -141,14 +141,14 @@ CREATE TABLE t3 ( f2 varchar(1)) ;
 EXPLAIN SELECT f2 FROM t3 WHERE (
 SELECT MAX( pk ) FROM t1
 WHERE EXISTS (
-SELECT DISTINCT f1
-FROM t2
+SELECT max(f1)
+FROM t2 GROUP BY f1
 )
 ) IS NULL ;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
 drop table t1, t2, t3;
 #
 # LP BUG#715034 Item_sum_distinct::clear(): Assertion `tree != 0' failed

mysql-test/r/subselect_no_mat.result

@@ -1669,7 +1669,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select NULL from `test`.`t2` group by 1) > <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(NULL) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1677,7 +1677,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,(<min>(select NULL from `test`.`t2` group by 1) <= <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(NULL) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1693,7 +1693,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1709,7 +1709,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -2986,9 +2986,9 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `tes
 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	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; Using temporary
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') group by `test`.`t2`.`one`,`test`.`t2`.`two` having (trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`))) and trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
 DROP TABLE t1,t2;
 set optimizer_switch=@tmp11867_optimizer_switch;
 CREATE TABLE t1 (a char(5), b char(5));
@@ -4467,18 +4467,18 @@ a
 drop table t1, t2;
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,<exists>(select 1 from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(1)))))
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 WHERE a > 3 GROUP BY a);
+Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,<exists>(select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`))))))
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,<exists>(select 1 from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` having (1 = <ref_null_helper>(1)))))
+Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,<exists>(select min(`test`.`t1`.`a`) from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`))))))
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.
@@ -4822,8 +4822,6 @@ SELECT * FROM t1
 WHERE EXISTS (SELECT DISTINCT a FROM t2 WHERE t1.a < t2.a ORDER BY b);
 pk	a
 1	10
-3	30
-2	20
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY b (b));
 INSERT INTO t1 VALUES (1,NULL), (9,NULL);
@@ -5247,18 +5245,21 @@ DROP table t1,t2;
 #
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 b
 0
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 #
 # Bug #11765713 58705:
@@ -5654,7 +5655,7 @@ WHERE f1_key != table2.f1_key AND f1_key >= table1.f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t2	ALL	f1_key	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t2	index	f1_key	f1_key	4	NULL	10	Using where; Using index
 DROP TABLE t1,t2;
 #
 # LP bug #826279: assertion failure with GROUP BY a result of subquery
@@ -5882,7 +5883,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
 EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	a	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index	NULL	a	4	NULL	1	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	4	func	2	Using index
 SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 a
 2009-01-01

mysql-test/r/subselect_no_opts.result

@@ -1665,7 +1665,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select NULL from `test`.`t2` group by 1) > <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(NULL) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1673,7 +1673,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,(<min>(select NULL from `test`.`t2` group by 1) <= <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(NULL) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1689,7 +1689,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1705,7 +1705,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -2982,9 +2982,9 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `tes
 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	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; Using temporary
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') group by `test`.`t2`.`one`,`test`.`t2`.`two` having (trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`))) and trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`))))) AS `test` from `test`.`t1`
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`))))) AS `test` from `test`.`t1`
 DROP TABLE t1,t2;
 set optimizer_switch=@tmp11867_optimizer_switch;
 CREATE TABLE t1 (a char(5), b char(5));
@@ -4463,18 +4463,18 @@ a
 drop table t1, t2;
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,<exists>(select 1 from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(1))))
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 WHERE a > 3 GROUP BY a);
+Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,<exists>(select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`)))))
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,<exists>(select 1 from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` having (1 = <ref_null_helper>(1))))
+Note	1003	select 1 AS `1` from `test`.`t1` where <in_optimizer>(1,<exists>(select min(`test`.`t1`.`a`) from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`)))))
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.
@@ -4818,8 +4818,6 @@ SELECT * FROM t1
 WHERE EXISTS (SELECT DISTINCT a FROM t2 WHERE t1.a < t2.a ORDER BY b);
 pk	a
 1	10
-3	30
-2	20
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY b (b));
 INSERT INTO t1 VALUES (1,NULL), (9,NULL);
@@ -5243,18 +5241,21 @@ DROP table t1,t2;
 #
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 b
 0
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 #
 # Bug #11765713 58705:
@@ -5650,7 +5651,7 @@ WHERE f1_key != table2.f1_key AND f1_key >= table1.f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t2	ALL	f1_key	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t2	index	f1_key	f1_key	4	NULL	10	Using where; Using index
 DROP TABLE t1,t2;
 #
 # LP bug #826279: assertion failure with GROUP BY a result of subquery
@@ -5878,7 +5879,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
 EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	a	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index	NULL	a	4	NULL	1	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	4	func	2	Using index
 SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 a
 2009-01-01

mysql-test/r/subselect_no_scache.result

@@ -1668,7 +1668,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select NULL from `test`.`t2` group by 1) > <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(NULL) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1676,7 +1676,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,(<min>(select NULL from `test`.`t2` group by 1) <= <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(NULL) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1692,7 +1692,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1708,7 +1708,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -2986,9 +2986,9 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `tes
 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	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; Using temporary
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') group by `test`.`t2`.`one`,`test`.`t2`.`two` having (trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`))) and trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`))))) AS `test` from `test`.`t1`
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`))))) AS `test` from `test`.`t1`
 DROP TABLE t1,t2;
 set optimizer_switch=@tmp11867_optimizer_switch;
 CREATE TABLE t1 (a char(5), b char(5));
@@ -4469,20 +4469,20 @@ a
 drop table t1, t2;
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 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);
+Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
+1	PRIMARY	<subquery2>	const	distinct_key	distinct_key	5	const	1	100.00	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from  <materialize> (select 1 from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`1` = 1)
+Note	1003	select 1 AS `1` from  <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` where (`test`.`t1`.`a` > 3) group by `test`.`t1`.`a`) join `test`.`t1` where (`<subquery2>`.`min(a)` = 1)
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.
@@ -4826,8 +4826,6 @@ SELECT * FROM t1
 WHERE EXISTS (SELECT DISTINCT a FROM t2 WHERE t1.a < t2.a ORDER BY b);
 pk	a
 1	10
-3	30
-2	20
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY b (b));
 INSERT INTO t1 VALUES (1,NULL), (9,NULL);
@@ -5252,18 +5250,21 @@ DROP table t1,t2;
 #
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 b
 0
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 #
 # Bug #11765713 58705:
@@ -5659,7 +5660,7 @@ WHERE f1_key != table2.f1_key AND f1_key >= table1.f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t2	ALL	f1_key	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t2	index	f1_key	f1_key	4	NULL	10	Using where; Using index
 DROP TABLE t1,t2;
 #
 # LP bug #826279: assertion failure with GROUP BY a result of subquery
@@ -5887,7 +5888,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
 EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	a	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index	NULL	a	4	NULL	1	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	4	func	2	Using index
 SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 a
 2009-01-01

mysql-test/r/subselect_no_semijoin.result

@@ -1665,7 +1665,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select NULL from `test`.`t2` group by 1) > <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(NULL) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
 select * from t3 where a >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where a >= some (select b from t2 group by 1);
@@ -1673,7 +1673,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,(<min>(select NULL from `test`.`t2` group by 1) <= <cache>(`test`.`t3`.`a`))))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(NULL) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
 select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
@@ -1689,7 +1689,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
@@ -1705,7 +1705,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
 2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,(<min>(select NULL from `test`.`t2` group by 1) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
 insert into t2 values (2,2), (2,1), (3,3), (3,1);
 select * from t3 where a > all (select max(b) from t2 group by a);
 a
@@ -2982,9 +2982,9 @@ Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `tes
 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	
-2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where; Using temporary
+2	MATERIALIZED	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`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),(`test`.`t1`.`one`,`test`.`t1`.`two`) in ( <materialize> (select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') group by `test`.`t2`.`one`,`test`.`t2`.`two` ), <primary_index_lookup>(`test`.`t1`.`one` in <temporary table> on distinct_key where ((`test`.`t1`.`one` = `<subquery2>`.`one`) and (`test`.`t1`.`two` = `<subquery2>`.`two`)))))) AS `test` from `test`.`t1`
+Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),(`test`.`t1`.`one`,`test`.`t1`.`two`) in ( <materialize> (select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where (`test`.`t2`.`flag` = '0') ), <primary_index_lookup>(`test`.`t1`.`one` in <temporary table> on distinct_key where ((`test`.`t1`.`one` = `<subquery2>`.`one`) and (`test`.`t1`.`two` = `<subquery2>`.`two`)))))) AS `test` from `test`.`t1`
 DROP TABLE t1,t2;
 set optimizer_switch=@tmp11867_optimizer_switch;
 CREATE TABLE t1 (a char(5), b char(5));
@@ -4463,18 +4463,18 @@ a
 drop table t1, t2;
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,1 in ( <materialize> (select 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);
+Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,1 in ( <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a` ), <primary_index_lookup>(1 in <temporary table> on distinct_key where ((1 = `<subquery2>`.`min(a)`))))))
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) 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	
 2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,1 in ( <materialize> (select 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`))))))
+Note	1003	select 1 AS `1` from `test`.`t1` where <expr_cache><1>(<in_optimizer>(1,1 in ( <materialize> (select min(`test`.`t1`.`a`) 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>`.`min(a)`))))))
 DROP TABLE t1;
 #
 # Bug#45061: Incorrectly market field caused wrong result.
@@ -4818,8 +4818,6 @@ SELECT * FROM t1
 WHERE EXISTS (SELECT DISTINCT a FROM t2 WHERE t1.a < t2.a ORDER BY b);
 pk	a
 1	10
-3	30
-2	20
 DROP TABLE t1,t2;
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY b (b));
 INSERT INTO t1 VALUES (1,NULL), (9,NULL);
@@ -5243,18 +5241,21 @@ DROP table t1,t2;
 #
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT b FROM t1
 WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
 GROUP BY b;
 b
 0
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 #
 # Bug #11765713 58705:
@@ -5650,7 +5651,7 @@ WHERE f1_key != table2.f1_key AND f1_key >= table1.f1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	table1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	table2	index	NULL	f1_key	4	NULL	10	Using where; Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t2	ALL	f1_key	NULL	NULL	NULL	10	Range checked for each record (index map: 0x1); Using temporary
+2	DEPENDENT SUBQUERY	t2	index	f1_key	f1_key	4	NULL	10	Using where; Using index
 DROP TABLE t1,t2;
 #
 # LP bug #826279: assertion failure with GROUP BY a result of subquery
@@ -5878,7 +5879,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
 EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	a	4	NULL	2	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index	NULL	a	4	NULL	1	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	4	func	2	Using index
 SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
 a
 2009-01-01

mysql-test/r/subselect_sj2_jcl6.result

@@ -972,10 +972,18 @@ SET join_cache_level = 3;
 EXPLAIN
 SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
+SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+a	b
+v	v
+EXPLAIN
+SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<subquery2>	hash_ALL	distinct_key	#hash#distinct_key	5	test.t1.b	1	Using join buffer (flat, BNLH join)
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	1	Using temporary
-SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
+SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
 a	b
 v	v
 set optimizer_switch=@tmp_optimizer_switch;

mysql-test/suite/innodb/r/innodb_mysql.result

@@ -1425,9 +1425,9 @@ DROP TABLE t1;
 create table t1 (a bit(1) not null,b int) engine=myisam;
 create table t2 (c int) engine=innodb;
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
+set @@optimizer_switch='in_to_exists=on,materialization=off';
 explain
-select b from t1 where a not in (select b from t1,t2 group by a) group by a;
+select b from t1 where a not in (select max(b) from t1,t2 group by a) group by a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	system	NULL	NULL	NULL	NULL	0	const row not found

mysql-test/suite/innodb_plugin/r/innodb_mysql.result

@@ -1425,9 +1425,9 @@ DROP TABLE t1;
 create table t1 (a bit(1) not null,b int) engine=myisam;
 create table t2 (c int) engine=innodb;
 set @save_optimizer_switch=@@optimizer_switch;
-set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
+set @@optimizer_switch='in_to_exists=on,materialization=off';
 explain
-select b from t1 where a not in (select b from t1,t2 group by a) group by a;
+select b from t1 where a not in (select max(b) from t1,t2 group by a) group by a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	system	NULL	NULL	NULL	NULL	0	const row not found

mysql-test/t/explain.test

@@ -243,12 +243,12 @@ FULLTEXT KEY(f1),UNIQUE(f1));
 INSERT INTO t1 VALUES ('test');
 
 EXPLAIN SELECT 1 FROM t1
-WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST (""))
+WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST (""))
 WHERE t1.f1 GROUP BY t1.f1));
 
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
- WHERE 1 > ALL((SELECT 1 FROM t1 RIGHT OUTER JOIN t1 a
+ WHERE 1 > ALL((SELECT t1.f1 FROM t1 RIGHT OUTER JOIN t1 a
  ON (MATCH(t1.f1) AGAINST (""))
  WHERE t1.f1 GROUP BY t1.f1))';
 
@@ -259,7 +259,7 @@ DEALLOCATE PREPARE stmt;
 
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
- WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a
+ WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a
  ON (MATCH(t1.f1) AGAINST (""))
  WHERE t1.f1 GROUP BY t1.f1))';
 

mysql-test/t/subselect.test

@@ -3418,8 +3418,8 @@ drop table t1, t2;
 
 CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 GROUP BY a);
-EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT 1 FROM t1 WHERE a > 3 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 GROUP BY a);
+EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1 IN (SELECT min(a) FROM t1 WHERE a > 3 GROUP BY a);
 DROP TABLE t1;
 
 --echo #
@@ -4442,7 +4442,8 @@ DROP table t1,t2;
 
 CREATE TABLE t1 (a int, b int) ;
 INSERT INTO t1 VALUES (0,0),(0,0);
-
+set @optimizer_switch_save=@@optimizer_switch;
+set @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=on';
 EXPLAIN
 SELECT b FROM t1
   WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
@@ -4451,7 +4452,7 @@ SELECT b FROM t1
 SELECT b FROM t1
   WHERE ('0') IN ( SELECT a  FROM t1 GROUP BY a )
     GROUP BY b;
-
+set @@optimizer_switch=@optimizer_switch_save;
 DROP TABLE t1;
 
 --echo #

mysql-test/t/subselect4.test

@@ -642,27 +642,27 @@ CREATE TABLE t2 (f11 varchar(1)) ;
 INSERT INTO t2 VALUES ('f'),('d');
 
 SET @old_optimizer_switch = @@session.optimizer_switch;
-SET SESSION optimizer_switch = 'materialization=on,in_to_exists=off,';
+SET @@optimizer_switch = 'materialization=on,in_to_exists=off,semijoin=off';
 
 EXPLAIN
 SELECT * FROM t1
 WHERE f3 = (
         SELECT t1.f3 FROM t1
-        WHERE ( t1.f10 ) IN ( SELECT f11 FROM t2 GROUP BY f11 ));
+        WHERE ( t1.f10 ) IN ( SELECT max(f11) FROM t2 GROUP BY f11 ));
 SELECT * FROM t1
 WHERE f3 = (
         SELECT t1.f3 FROM t1
-        WHERE ( t1.f10 ) IN ( SELECT f11 FROM t2 GROUP BY f11 ));
+        WHERE ( t1.f10 ) IN ( SELECT max(f11) FROM t2 GROUP BY f11 ));
 
 EXPLAIN
 SELECT * FROM t1
 WHERE f3 = (
         SELECT f3 FROM t1
-        WHERE ( f10, f10 ) IN ( SELECT f11, f11 FROM t2 GROUP BY f11 ));
+        WHERE ( f10, f10 ) IN ( SELECT max(f11), f11 FROM t2 GROUP BY f11 ));
 SELECT * FROM t1
 WHERE f3 = (
         SELECT f3 FROM t1
-        WHERE ( f10, f10 ) IN ( SELECT f11, f11 FROM t2 GROUP BY f11 ));
+        WHERE ( f10, f10 ) IN ( SELECT max(f11), f11 FROM t2 GROUP BY f11 ));
 
 SET SESSION optimizer_switch = @old_optimizer_switch;
 drop table t1,t2;
@@ -1084,7 +1084,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE
 (SELECT f2 FROM t2
  WHERE f4 <= ALL
-       (SELECT SQ1_t1.f4
+       (SELECT max(SQ1_t1.f4)
         FROM t3 AS SQ1_t1 JOIN t3 AS SQ1_t3 ON SQ1_t3.f4
         GROUP BY SQ1_t1.f4));
 
@@ -1305,47 +1305,47 @@ INSERT INTO t2 VALUES
 set @save_optimizer_switch=@@optimizer_switch;
 SET optimizer_switch='outer_join_with_cache=off';
 
-set @@optimizer_switch = 'materialization=off';
+set @@optimizer_switch = 'in_to_exists=on,materialization=off,semijoin=off';
 
 EXPLAIN
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 
-SET @@optimizer_switch = 'materialization=on';
+set @@optimizer_switch = 'in_to_exists=off,materialization=on,semijoin=off';
 
 EXPLAIN
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 
 SELECT alias2.f1 , alias2.f2
 FROM t0 AS alias1
 RIGHT JOIN t0 AS alias2 ON alias2.f10
-WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT f2 , f1 FROM t0 GROUP BY f2 , f1 );
+WHERE ( alias2.f1 , alias2.f2 ) IN ( SELECT max(f2) , f1 FROM t0 GROUP BY f2 , f1 );
 
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
-SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT f1a, f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b, f2b) IN (SELECT max(f1a), f2a FROM t1 GROUP BY f1a, f2a);
 
 EXPLAIN
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
-SELECT * FROM t2 WHERE (f1b) IN (SELECT f1a FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
+SELECT * FROM t2 WHERE (f1b) IN (SELECT max(f1a) FROM t1 GROUP BY f1a, f2a);
 
 set @@optimizer_switch=@save_optimizer_switch;
 

mysql-test/t/subselect_mat_cost_bugs.test

@@ -167,8 +167,8 @@ CREATE TABLE t3 ( f2 varchar(1)) ;
 EXPLAIN SELECT f2 FROM t3 WHERE (
         SELECT MAX( pk ) FROM t1
         WHERE EXISTS (
-                SELECT DISTINCT f1
-                FROM t2
+                SELECT max(f1)
+                FROM t2 GROUP BY f1
         )
 ) IS NULL ;
 

mysql-test/t/subselect_sj2_jcl6.test

@@ -94,6 +94,10 @@ EXPLAIN
 SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
 SELECT * FROM t1 WHERE b IN (SELECT a FROM t2 GROUP BY a);
 
+EXPLAIN
+SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
+SELECT * FROM t1 WHERE b IN (SELECT max(a) FROM t2 GROUP BY a);
+
 set optimizer_switch=@tmp_optimizer_switch;
 set join_cache_level=default;
 

mysql-test/t/subselect_sj_mat.test

@@ -88,8 +88,8 @@ select * from t1i where a1 in (select b1 from t2i where b1 > '0');
 
 --replace_column 6 # 8 # 11 #
 explain extended
-select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
-select * from t1i where a1 in (select b1 from t2i where b1 > '0' group by b1);
+select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b1);
+select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b1);
 
 --replace_column 7 #
 --replace_regex /it1.*/_it1_idx/  /test.t2i.*/_ref_/  /Using index$// /Using where$//
@@ -99,8 +99,8 @@ select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0');
 
 --replace_column 6 # 7 # 8 # 11 #
 explain extended
-select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
-select * from t1i where (a1, a2) in (select b1, b2 from t2i where b1 > '0' group by b1, b2);
+select * from t1i where (a1, a2) in (select b1, max(b2) from t2i where b1 > '0' group by b1);
+select * from t1i where (a1, a2) in (select b1, max(b2) from t2i where b1 > '0' group by b1);
 
 --replace_column 6 # 7 # 8 # 11 #
 explain extended
@@ -835,14 +835,14 @@ create table t2 (b1 int);
 insert into t1 values (5);
 
 # Query with group by, executed via materialization
-explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
-select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
+explain select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
+select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 # Query with group by, executed via IN=>EXISTS
 set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch=@optimizer_switch_local_default;
 set @@optimizer_switch='materialization=off,in_to_exists=on';
-explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
-select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
+explain select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
+select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 
 # Executed with materialization
 set @@optimizer_switch=@optimizer_switch_local_default;
@@ -900,7 +900,7 @@ WHERE (t1i)  IN (
    SELECT t2i
    FROM t2  
    WHERE (t2i)  IN (  
-     SELECT t3i
+     SELECT max(t3i)
      FROM t3  
      GROUP BY t3i
      )  

sql/item_subselect.cc

@@ -178,7 +178,7 @@ void Item_allany_subselect::cleanup()
   */
   for (SELECT_LEX *sl= unit->first_select();
        sl; sl= sl->next_select())
-    if (test_strategy(SUBS_MAXMIN_INJECTED))
+    if (test_set_strategy(SUBS_MAXMIN_INJECTED))
       sl->with_sum_func= false;
   Item_in_subselect::cleanup();
 }

sql/sql_select.cc

@@ -424,6 +424,73 @@ fix_inner_refs(THD *thd, List<Item> &all_fields, SELECT_LEX *select,
   return false;
 }
 
+/**
+   The following clauses are redundant for subqueries:
+
+   DISTINCT
+   GROUP BY   if there are no aggregate functions and no HAVING
+              clause
+
+   Because redundant clauses are removed both from JOIN and
+   select_lex, the removal is permanent. Thus, it only makes sense to
+   call this function for normal queries and on first execution of
+   SP/PS
+
+   @param subq_select_lex   select_lex that is part of a subquery 
+                            predicate. This object and the associated 
+                            join is modified.
+*/
+
+static
+void remove_redundant_subquery_clauses(st_select_lex *subq_select_lex)
+{
+  Item_subselect *subq_predicate= subq_select_lex->master_unit()->item;
+  /*
+    The removal should happen for IN, ALL, ANY and EXISTS subqueries,
+    which means all but single row subqueries. Example single row
+    subqueries: 
+       a) SELECT * FROM t1 WHERE t1.a = (<single row subquery>) 
+       b) SELECT a, (<single row subquery) FROM t1
+   */
+  if (subq_predicate->substype() == Item_subselect::SINGLEROW_SUBS)
+    return;
+
+  /* A subquery that is not single row should be one of IN/ALL/ANY/EXISTS. */
+  DBUG_ASSERT (subq_predicate->substype() == Item_subselect::EXISTS_SUBS ||
+               subq_predicate->is_in_predicate());
+
+  if (subq_select_lex->options & SELECT_DISTINCT)
+  {
+    subq_select_lex->join->select_distinct= false;
+    subq_select_lex->options&= ~SELECT_DISTINCT;
+  }
+
+  /*
+    Remove GROUP BY if there are no aggregate functions and no HAVING
+    clause
+  */
+  if (subq_select_lex->group_list.elements &&
+      !subq_select_lex->with_sum_func && !subq_select_lex->join->having)
+  {
+    subq_select_lex->join->group_list= NULL;
+    subq_select_lex->group_list.empty();
+  }
+
+  /*
+    TODO: This would prevent processing quries with ORDER BY ... LIMIT
+    therefore we disable this optimization for now.
+    Remove GROUP BY if there are no aggregate functions and no HAVING
+    clause
+  if (subq_select_lex->group_list.elements &&
+      !subq_select_lex->with_sum_func && !subq_select_lex->join->having)
+  {
+    subq_select_lex->join->group_list= NULL;
+    subq_select_lex->group_list.empty();
+  }
+  */
+}
+
+
 /**
   Function to setup clauses without sum functions.
 */
@@ -522,6 +589,22 @@ JOIN::prepare(Item ***rref_pointer_array,
                                     FALSE, SELECT_ACL, SELECT_ACL, FALSE))
       DBUG_RETURN(-1);
 
+  /*
+    Permanently remove redundant parts from the query if
+      1) This is a subquery
+      2) This is the first time this query is optimized (since the
+         transformation is permanent
+      3) Not normalizing a view. Removal should take place when a
+         query involving a view is optimized, not when the view
+         is created
+  */
+  if (select_lex->master_unit()->item &&                               // 1)
+      select_lex->first_cond_optimization &&                           // 2)
+      !(thd->lex->context_analysis_only & CONTEXT_ANALYSIS_ONLY_VIEW)) // 3)
+  {
+    remove_redundant_subquery_clauses(select_lex);
+  }
+  
   /*
     TRUE if the SELECT list mixes elements with and without grouping,
     and there is no GROUP BY clause. Mixing non-aggregated fields with