Make subquery Materialization, as well as semi-join Materialization be shown

in EXPLAIN as select_type==MATERIALIZED. 

Before, we had select_type==SUBQUERY and it was difficult to tell materialized
subqueries from uncorrelated scalar-context subqueries.

mysql-test/r/func_group.result

@@ -1865,7 +1865,7 @@ SELECT v
 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 Warnings:
 Warning	1292	Truncated incorrect INTEGER value: 'j'
 
@@ -1891,7 +1891,7 @@ SELECT v
 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No matching min/max row
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 
 #
 # 3) Test that subquery materialization is setup for query with
@@ -1915,7 +1915,7 @@ SELECT v
 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 
 #
 # 4) Test that subquery materialization is setup for query with
@@ -1940,7 +1940,7 @@ SELECT v
 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
-3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 set optimizer_switch=@tmp_optimizer_switch;
 
@@ -1967,8 +1967,8 @@ SELECT v
 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	2	Using where; Using index
-3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 set @@optimizer_switch=@save_optimizer_switch;
 #
 # Cleanup for BUG#46680

mysql-test/r/group_by.result

@@ -1544,7 +1544,7 @@ EXPLAIN SELECT 1 FROM t1 WHERE a IN
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	PRIMARY,i2	PRIMARY	4	NULL	144	Using index
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	144	
 CREATE TABLE t2 (a INT, b INT, KEY(a));
 INSERT INTO t2 VALUES (1, 1), (2, 2), (3,3), (4,4);
 EXPLAIN SELECT a, SUM(b) FROM t2 GROUP BY a LIMIT 2;

mysql-test/r/group_min_max.result

@@ -2403,7 +2403,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	8	Using where
 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
+2	MATERIALIZED	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);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

mysql-test/r/myisam_icp.result

@@ -763,8 +763,8 @@ t2.b NOT IN (SELECT t4.b FROM t3 STRAIGHT_JOIN t4 WHERE t4.b <= 2 AND t4.c = t3.
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t4	range	b	b	5	NULL	1	Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join)
+2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t4	range	b	b	5	NULL	1	Using index condition; Using where; Rowid-ordered scan; Using join buffer (flat, BNL join)
 SELECT * FROM t1 LEFT JOIN t2 ON t1.c=t2.b
 WHERE 
 t2.b NOT IN (SELECT t4.b FROM t3 STRAIGHT_JOIN t4 WHERE t4.b <= 2 AND t4.c = t3.c);

mysql-test/r/subselect.result

@@ -2973,7 +2973,7 @@ explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FR
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
+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` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
 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;
@@ -3563,7 +3563,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 a	b
@@ -3575,7 +3575,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
 insert into t1 values (1,1),(2,2);
@@ -4466,14 +4466,14 @@ 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
+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);
 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	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+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)
 DROP TABLE t1;
@@ -5160,8 +5160,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	24	Using where
 1	PRIMARY	ot4	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it2	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
+2	MATERIALIZED	it2	ALL	NULL	NULL	NULL	NULL	4	
+2	MATERIALIZED	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
 DROP TABLE IF EXISTS ot1, ot4, it2, it3;
 #
 # Bug#729039: NULL keys used to evaluate subquery
@@ -5861,7 +5861,7 @@ SET @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=off,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	SUBQUERY	t1	index	NULL	a	4	NULL	2	Using index
+2	MATERIALIZED	t1	index	NULL	a	4	NULL	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/subselect3.result

@@ -1180,7 +1180,7 @@ 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	<subquery2>	ALL	distinct_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
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 select * from t3 where a in (select a from t2);
 a	filler
 1	filler
@@ -1474,7 +1474,7 @@ FROM t3
 );
 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	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where (not(<expr_cache><(select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9))>(<in_optimizer>((select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9)),(select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9)) in ( <materialize> (select `test`.`t3`.`b` from `test`.`t3` ), <primary_index_lookup>(9 in <temporary table> on distinct_key where ((9 = `<subquery3>`.`b`))))))))

mysql-test/r/subselect3_jcl6.result

@@ -1189,7 +1189,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 select * from t3 where a in (select a from t2);
 a	filler
 1	filler
@@ -1483,7 +1483,7 @@ FROM t3
 );
 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	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where (not(<expr_cache><(select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9))>(<in_optimizer>((select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9)),(select `test`.`t2`.`a` from `test`.`t2` where (`test`.`t2`.`a` = 9)) in ( <materialize> (select `test`.`t3`.`b` from `test`.`t3` ), <primary_index_lookup>(9 in <temporary table> on distinct_key where ((9 = `<subquery3>`.`b`))))))))

mysql-test/r/subselect_cache.result

@@ -1807,7 +1807,7 @@ set optimizer_switch='default,semijoin=off,materialization=on,subquery_cache=on'
 explain select * from t1 where a in (select pk from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	15	Using where
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	10	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	10	
 flush status;
 select * from t1 where a in (select pk from t2);
 a	b

mysql-test/r/subselect_extra.result

@@ -308,7 +308,7 @@ EXPLAIN SELECT 1 FROM t1 WHERE a IN
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	PRIMARY,i2	PRIMARY	4	NULL	144	Using index
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	4	func	1	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	144	
 CREATE TABLE t2 (a INT, b INT, KEY(a));
 INSERT INTO t2 VALUES (1, 1), (2, 2), (3,3), (4,4);
 EXPLAIN SELECT a, SUM(b) FROM t2 GROUP BY a LIMIT 2;

mysql-test/r/subselect_extra_no_semijoin.result

@@ -311,7 +311,7 @@ EXPLAIN SELECT 1 FROM t1 WHERE a IN
 (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	144	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	144	
 CREATE TABLE t2 (a INT, b INT, KEY(a));
 INSERT INTO t2 VALUES (1, 1), (2, 2), (3,3), (4,4);
 EXPLAIN SELECT a, SUM(b) FROM t2 GROUP BY a LIMIT 2;
@@ -324,7 +324,7 @@ EXPLAIN SELECT 1 FROM t2 WHERE a IN
 (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	144	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	144	
 DROP TABLE t1, t2;
 # 
 # From derived_view.test
@@ -349,7 +349,7 @@ WHERE t.a IN (SELECT b FROM t1);
 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	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
-3	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
+3	MATERIALIZED	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,0 AS `a`,0 AS `b` from `test`.`t1` left join `test`.`t2` on((0 <> 0)) where <expr_cache><0>(<in_optimizer>(0,0 in ( <materialize> (select 0 from `test`.`t1` ), <primary_index_lookup>(0 in <temporary table> on distinct_key where ((0 = `<subquery3>`.`b`))))))
 SELECT * FROM t2 RIGHT JOIN v1 AS t ON t.a != 0
@@ -362,7 +362,7 @@ WHERE t.a IN (SELECT b FROM t1);
 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	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
-2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
+2	MATERIALIZED	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,0 AS `a`,0 AS `b` from `test`.`t1` left join `test`.`t2` on((0 <> 0)) where <expr_cache><0>(<in_optimizer>(0,0 in ( <materialize> (select 0 from `test`.`t1` ), <primary_index_lookup>(0 in <temporary table> on distinct_key where ((0 = `<subquery2>`.`b`))))))
 DROP VIEW v1;

mysql-test/r/subselect_mat_cost.result

@@ -65,7 +65,7 @@ Name LIKE 'L%') AND
 surfacearea > 1000000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	Country	ALL	Name,SurfaceArea	NULL	NULL	NULL	239	Using where
-2	SUBQUERY	City	ALL	Population,Country	NULL	NULL	NULL	4080	Using where
+2	MATERIALIZED	City	ALL	Population,Country	NULL	NULL	NULL	4080	Using where
 SELECT Name FROM Country
 WHERE (Code IN (select Country from City where City.Population > 100000) OR
 Name LIKE 'L%') AND
@@ -134,7 +134,7 @@ City.name LIKE '%Island%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	Country	ALL	PRIMARY,SurfaceArea	NULL	NULL	NULL	239	Using where
 1	PRIMARY	City	ref	Country	Country	3	world.Country.Code	18	Using where
-2	SUBQUERY	CountryLanguage	ALL	Percentage,Language	NULL	NULL	NULL	984	Using where
+2	MATERIALIZED	CountryLanguage	ALL	Percentage,Language	NULL	NULL	NULL	984	Using where
 SELECT *
 FROM Country, City
 WHERE City.Country = Country.Code AND
@@ -204,7 +204,7 @@ OR
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	Country	ALL	PRIMARY,SurfaceArea	NULL	NULL	NULL	239	Using where
 1	PRIMARY	City	ref	Country	Country	3	world.Country.Code	18	Using where
-3	SUBQUERY	CountryLanguage	index	PRIMARY,Language	PRIMARY	33	NULL	984	Using index
+3	MATERIALIZED	CountryLanguage	index	PRIMARY,Language	PRIMARY	33	NULL	984	Using index
 2	DEPENDENT SUBQUERY	CountryLanguage	unique_subquery	PRIMARY,Percentage,Language	PRIMARY	33	func,func	1	Using where
 SELECT City.Name, Country.Name
 FROM City,Country
@@ -233,7 +233,7 @@ where City.id not in (select capital from Country
 where capital is not null and population < 100000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	City	index	NULL	PRIMARY	4	NULL	4080	Using where; Using index
-2	SUBQUERY	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
+2	MATERIALIZED	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
 
 Q2.2e:
 Countries that speak French, but do not speak English
@@ -287,7 +287,7 @@ AND Code = Country;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	CountryLanguage	range	PRIMARY,Language	Language	30	NULL	45	Using index condition; Using where; Rowid-ordered scan
 1	PRIMARY	Country	eq_ref	PRIMARY	PRIMARY	3	world.CountryLanguage.Country	1	Using index condition
-2	SUBQUERY	CountryLanguage	ref	PRIMARY,Language	Language	30	const	47	Using index condition
+2	MATERIALIZED	CountryLanguage	ref	PRIMARY,Language	Language	30	const	47	Using index condition
 SELECT Country.Name
 FROM Country, CountryLanguage 
 WHERE Code NOT IN (SELECT Country FROM CountryLanguage WHERE Language = 'English')
@@ -371,8 +371,8 @@ FROM City LEFT JOIN Country ON (Country = Code)
 HAVING City.Name LIKE "Santa%");
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	CountryLanguage	index	NULL	PRIMARY	33	NULL	984	Using where; Using index
-2	SUBQUERY	City	ALL	NULL	NULL	NULL	NULL	4080	
-2	SUBQUERY	Country	eq_ref	PRIMARY	PRIMARY	3	world.City.Country	1	Using index
+2	MATERIALIZED	City	ALL	NULL	NULL	NULL	NULL	4080	
+2	MATERIALIZED	Country	eq_ref	PRIMARY	PRIMARY	3	world.City.Country	1	Using index
 select count(*)
 from CountryLanguage
 where (Language, Country) NOT IN
@@ -399,10 +399,10 @@ WHERE Code = Country GROUP BY Code)
 order by Country;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	CountryLanguage	index	NULL	PRIMARY	33	NULL	984	Using where; Using index
-3	SUBQUERY	CountryLanguage	index	PRIMARY	PRIMARY	33	NULL	984	Using index; Using temporary
-3	SUBQUERY	Country	eq_ref	PRIMARY	PRIMARY	3	world.CountryLanguage.Country	1	Using index
-2	SUBQUERY	CountryLanguage	index	PRIMARY	PRIMARY	33	NULL	984	Using index; Using temporary
-2	SUBQUERY	Country	eq_ref	PRIMARY	PRIMARY	3	world.CountryLanguage.Country	1	Using index
+3	MATERIALIZED	CountryLanguage	index	PRIMARY	PRIMARY	33	NULL	984	Using index; Using temporary
+3	MATERIALIZED	Country	eq_ref	PRIMARY	PRIMARY	3	world.CountryLanguage.Country	1	Using index
+2	MATERIALIZED	CountryLanguage	index	PRIMARY	PRIMARY	33	NULL	984	Using index; Using temporary
+2	MATERIALIZED	Country	eq_ref	PRIMARY	PRIMARY	3	world.CountryLanguage.Country	1	Using index
 select count(*)
 from CountryLanguage
 where
@@ -429,7 +429,7 @@ capital is null);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
 1	PRIMARY	City	eq_ref	PRIMARY	PRIMARY	4	world.Country.Capital	1	Using where
-2	SUBQUERY	City	index	NULL	CityName	35	NULL	4080	Using index
+2	MATERIALIZED	City	index	NULL	CityName	35	NULL	4080	Using index
 select * from Country, City
 where capital = id and
 (City.name in (SELECT name FROM City
@@ -450,7 +450,7 @@ WHERE Country.Code NOT IN
 (SELECT Country FROM City GROUP BY Name HAVING COUNT(Name) = 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
-2	SUBQUERY	City	ALL	NULL	NULL	NULL	NULL	4080	Using temporary
+2	MATERIALIZED	City	ALL	NULL	NULL	NULL	NULL	4080	Using temporary
 SELECT Name
 FROM Country
 WHERE Country.Code NOT IN
@@ -480,7 +480,7 @@ from City
 where City.population > 10000000;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	City	range	Population	Population	5	NULL	4	Using index condition; Rowid-ordered scan
-2	SUBQUERY	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
+2	MATERIALIZED	Country	ALL	NULL	NULL	NULL	NULL	239	Using where
 select Name, City.id in (select capital from Country where capital is not null) as is_capital
 from City
 where City.population > 10000000;
@@ -514,7 +514,7 @@ HAVING City.Name IN (select Name from Country where population < 1000000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	City	ALL	Country	NULL	NULL	NULL	4080	Using temporary; Using filesort
 1	PRIMARY	Country	eq_ref	PRIMARY	PRIMARY	3	world.City.Country	1	Using index
-2	SUBQUERY	Country	ALL	Name	NULL	NULL	NULL	239	Using where
+2	MATERIALIZED	Country	ALL	Name	NULL	NULL	NULL	239	Using where
 SELECT City.Name, City.Population
 FROM City JOIN Country ON City.Country = Country.Code
 GROUP BY City.Name

mysql-test/r/subselect_mat_cost_bugs.result

@@ -260,8 +260,8 @@ WHERE alias1.f11 OR alias1.f3 = 50 AND alias1.f10
 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	alias1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	alias1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	MATERIALIZED	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 SELECT * FROM t2
 WHERE ( f12 ) IN (
 SELECT alias2.f3
@@ -277,8 +277,8 @@ FROM t1 AS alias1, t1 AS alias2
 WHERE (alias2.f10 = alias1.f11) AND (alias1.f11 OR alias1.f3 = 50 AND alias1.f10));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	alias1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	alias1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	MATERIALIZED	alias2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 SELECT * FROM t2
 WHERE ( f12 ) IN (
 SELECT alias2.f3
@@ -380,14 +380,14 @@ set @@optimizer_switch='in_to_exists=off,materialization=on,partial_match_rowid_
 explain select * from t1 where c1 = 'a2' and (c1, c2) not in (select * from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 select * from t1 where c1 = 'a2' and (c1, c2) not in (select * from t2);
 c1	c2
 set @@optimizer_switch='in_to_exists=off,materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off';
 explain select * from t1 where c1 = 'a2' and (c1, c2) not in (select * from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
 select * from t1 where c1 = 'a2' and (c1, c2) not in (select * from t2);
 c1	c2
 drop table t1, t2;

mysql-test/r/subselect_no_mat.result

@@ -5860,7 +5860,7 @@ SET @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=off,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	SUBQUERY	t1	index	NULL	a	4	NULL	2	Using index
+2	MATERIALIZED	t1	index	NULL	a	4	NULL	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

@@ -5856,7 +5856,7 @@ SET @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=off,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	SUBQUERY	t1	index	NULL	a	4	NULL	2	Using index
+2	MATERIALIZED	t1	index	NULL	a	4	NULL	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

@@ -2977,7 +2977,7 @@ explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FR
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
+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` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
 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;
@@ -3567,7 +3567,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 a	b
@@ -3579,7 +3579,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
 insert into t1 values (1,1),(2,2);
@@ -4470,14 +4470,14 @@ 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	<subquery2>	const	distinct_key	distinct_key	4	const	1	100.00	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
+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);
 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	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+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)
 DROP TABLE t1;
@@ -5164,8 +5164,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	24	Using where
 1	PRIMARY	ot4	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it2	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
+2	MATERIALIZED	it2	ALL	NULL	NULL	NULL	NULL	4	
+2	MATERIALIZED	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
 DROP TABLE IF EXISTS ot1, ot4, it2, it3;
 #
 # Bug#729039: NULL keys used to evaluate subquery
@@ -5865,7 +5865,7 @@ SET @@optimizer_switch='semijoin=off,materialization=on,in_to_exists=off,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	SUBQUERY	t1	index	NULL	a	4	NULL	2	Using index
+2	MATERIALIZED	t1	index	NULL	a	4	NULL	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_sj.result

@@ -79,7 +79,7 @@ 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	
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-2	SUBQUERY	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
+2	MATERIALIZED	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on((<in_optimizer>(`test`.`B`.`A`,`test`.`B`.`A` in ( <mAteriAlize> (select `test`.`t10`.`pk` from `test`.`t10` ), <primAry_index_lookup>(`test`.`B`.`A` in <temporAry tABle> on distinct_key where ((`test`.`B`.`A` = `<suBquery2>`.`pk`))))) And (`test`.`A`.`A` = `test`.`t1`.`A`))) where 1
 t2 should be wrapped into OJ-nest, so we have "t1 LJ (t2 J t10)"
@@ -88,7 +88,7 @@ select * from t1 left join t2 on (t2.A= t1.A And t2.A in (select pk from t10));
 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	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-2	SUBQUERY	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
+2	MATERIALIZED	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on((<in_optimizer>(`test`.`t2`.`A`,`test`.`t2`.`A` in ( <mAteriAlize> (select `test`.`t10`.`pk` from `test`.`t10` ), <primAry_index_lookup>(`test`.`t2`.`A` in <temporAry tABle> on distinct_key where ((`test`.`t2`.`A` = `<suBquery2>`.`pk`))))) And (`test`.`t2`.`A` = `test`.`t1`.`A`))) where 1
 we shouldn't flatten if we're going to get a join of > MAX_TABLES.
@@ -726,8 +726,8 @@ FROM it1 LEFT JOIN it2 ON it2.datetime_key);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	11	
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it1	index	NULL	int_key	4	NULL	2	Using index
-2	SUBQUERY	it2	ALL	int_key,datetime_key	NULL	NULL	NULL	20	Using where
+2	MATERIALIZED	it1	index	NULL	int_key	4	NULL	2	Using index
+2	MATERIALIZED	it2	ALL	int_key,datetime_key	NULL	NULL	NULL	20	Using where
 DROP TABLE ot1, it1, it2;
 # End of BUG#38075
 #
@@ -800,7 +800,7 @@ EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk
 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>	eq_ref	distinct_key	distinct_key	13	func,func	1	100.00	
-2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
+2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
 SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
@@ -969,7 +969,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
-2	SUBQUERY	t1	ALL	varchar_key	NULL	NULL	NULL	15	100.00	Using where
+2	MATERIALIZED	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_key` < 'n') xor `test`.`t1`.`pk`))
 SELECT varchar_nokey
@@ -1052,8 +1052,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
 1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	14	func	1	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	14	func	1	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1275,8 +1275,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	C	ALL	NULL	NULL	NULL	NULL	3	
-3	SUBQUERY	D	ALL	NULL	NULL	NULL	NULL	3	
+2	MATERIALIZED	C	ALL	NULL	NULL	NULL	NULL	3	
+3	MATERIALIZED	D	ALL	NULL	NULL	NULL	NULL	3	
 drop table t1, t2;
 # 
 # BUG#784441: Abort on semijoin with a view as the inner table
@@ -1291,7 +1291,7 @@ SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	<derived3>	system	NULL	NULL	NULL	NULL	1	
+2	MATERIALIZED	<derived3>	system	NULL	NULL	NULL	NULL	1	
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
 a	a
@@ -1386,8 +1386,8 @@ explain select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a=t2.a);
 b
 drop table t1, t2, t3;
@@ -1990,8 +1990,8 @@ SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
-2	SUBQUERY	t2	ref	b	b	4	test.t3.a	1	Using index
+2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
+2	MATERIALIZED	t2	ref	b	b	4	test.t3.a	1	Using index
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
 a
 19

mysql-test/r/subselect_sj2.result

@@ -48,7 +48,7 @@ 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	<subquery2>	ALL	distinct_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	Using where
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 select * from t2 where b in (select a from t1);
 a	b
 1	1
@@ -68,7 +68,7 @@ explain select * from t3 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	20	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	
 select * from t3 where b in (select a from t1);
 a	b	pk1	pk2	pk3
 1	1	1	1	1
@@ -94,7 +94,7 @@ 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	<subquery2>	ALL	distinct_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	Using where
+2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
 set @save_ecp= @@engine_condition_pushdown;
 set engine_condition_pushdown=0;
 select * from t3 where b in (select A.a+B.a from t0 A, t0 B where B.a<5);
@@ -148,7 +148,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -181,7 +181,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	32	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -216,7 +216,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -249,7 +249,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	52	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -290,9 +290,9 @@ from t0 where a in
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
-2	SUBQUERY	t1	index	a	a	5	NULL	10	Using where; Using index
-2	SUBQUERY	t2	ref	a	a	5	test.t1.a	1	Using index
-2	SUBQUERY	t3	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
+2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
 ID int(11) NOT NULL auto_increment,
@@ -370,7 +370,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	3	func	1	
-2	SUBQUERY	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
+2	MATERIALIZED	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
 SELECT Name FROM t1 
 WHERE t1.Code IN (
 SELECT t2.CountryCode FROM t2 WHERE Population > 5000000);
@@ -605,7 +605,7 @@ select * from t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t3));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
-2	SUBQUERY	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
+2	MATERIALIZED	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
 drop table t0, t1, t2, t3;
 create table t1 (a int);
 insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -719,7 +719,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t3	index	a	a	5	NULL	30000	Using index
+2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
 1000
@@ -878,7 +878,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);

mysql-test/r/subselect_sj2_jcl6.result

@@ -57,7 +57,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ref	b	b	5	test.t1.a	2	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 select * from t2 where b in (select a from t1);
 a	b
 1	1
@@ -77,7 +77,7 @@ explain select * from t3 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	20	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	
 select * from t3 where b in (select a from t1);
 a	b	pk1	pk2	pk3
 1	1	1	1	1
@@ -103,7 +103,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	10	
 1	PRIMARY	t3	ref	b	b	5	test.t0.a	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
-2	SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
 set @save_ecp= @@engine_condition_pushdown;
 set engine_condition_pushdown=0;
 select * from t3 where b in (select A.a+B.a from t0 A, t0 B where B.a<5);
@@ -157,7 +157,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	hash_ALL	NULL	#hash#$hj	5	test.it.a	32	Using where; Using join buffer (flat, BNLH join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	Using where
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	Using where
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -190,7 +190,7 @@ from t2 ot where a in (select a from t1 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	22	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	32	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -225,7 +225,7 @@ from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	hash_ALL	NULL	#hash#$hj	5	test.it.a	52	Using where; Using join buffer (flat, BNLH join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	Using where
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	Using where
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -258,7 +258,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	52	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -299,9 +299,9 @@ from t0 where a in
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
-2	SUBQUERY	t1	index	a	a	5	NULL	10	Using where; Using index
-2	SUBQUERY	t2	ref	a	a	5	test.t1.a	1	Using index
-2	SUBQUERY	t3	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
+2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
 ID int(11) NOT NULL auto_increment,
@@ -379,7 +379,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	3	func	1	
-2	SUBQUERY	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
+2	MATERIALIZED	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
 SELECT Name FROM t1 
 WHERE t1.Code IN (
 SELECT t2.CountryCode FROM t2 WHERE Population > 5000000);
@@ -616,7 +616,7 @@ select * from t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t3));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
 1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t1.a	3	Using where; Using join buffer (flat, BNLH join)
-2	SUBQUERY	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
+2	MATERIALIZED	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
 drop table t0, t1, t2, t3;
 create table t1 (a int);
 insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -730,7 +730,7 @@ explain select count(a) from t2 where a in ( SELECT  a FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	1000	Using index
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t3	index	a	a	5	NULL	30000	Using index
+2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
 1000
@@ -889,7 +889,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t3.a	1	Using where; Using join buffer (flat, BNLH join)
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (incremental, BNL join)
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);

mysql-test/r/subselect_sj2_mat.result

@@ -50,7 +50,7 @@ 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	<subquery2>	ALL	distinct_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	Using where
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 select * from t2 where b in (select a from t1);
 a	b
 1	1
@@ -70,7 +70,7 @@ explain select * from t3 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	20	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	3	
 select * from t3 where b in (select a from t1);
 a	b	pk1	pk2	pk3
 1	1	1	1	1
@@ -96,7 +96,7 @@ 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	<subquery2>	ALL	distinct_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	Using where
+2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
 set @save_ecp= @@engine_condition_pushdown;
 set engine_condition_pushdown=0;
 select * from t3 where b in (select A.a+B.a from t0 A, t0 B where B.a<5);
@@ -150,7 +150,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -183,7 +183,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	32	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	32	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -218,7 +218,7 @@ 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	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	22	
 1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
 from t1 ot where a in (select a from t2 it);
@@ -251,7 +251,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	52	
+2	MATERIALIZED	it	ALL	NULL	NULL	NULL	NULL	52	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) 
 from t2 ot where a in (select a from t1 it);
@@ -292,9 +292,9 @@ from t0 where a in
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	9	func	1	Using where
-2	SUBQUERY	t1	index	a	a	5	NULL	10	Using where; Using index
-2	SUBQUERY	t2	ref	a	a	5	test.t1.a	1	Using index
-2	SUBQUERY	t3	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t1	index	a	a	5	NULL	10	Using where; Using index
+2	MATERIALIZED	t2	ref	a	a	5	test.t1.a	1	Using index
+2	MATERIALIZED	t3	ref	a	a	5	test.t1.a	1	Using index
 drop table t0, t1,t2,t3;
 CREATE TABLE t1 (
 ID int(11) NOT NULL auto_increment,
@@ -372,7 +372,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	3	func	1	
-2	SUBQUERY	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
+2	MATERIALIZED	t2	ALL	CountryCode	NULL	NULL	NULL	545	Using where
 SELECT Name FROM t1 
 WHERE t1.Code IN (
 SELECT t2.CountryCode FROM t2 WHERE Population > 5000000);
@@ -607,7 +607,7 @@ select * from t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t3));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
-2	SUBQUERY	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
+2	MATERIALIZED	t3	index	PRIMARY	PRIMARY	4	NULL	10	Using index
 drop table t0, t1, t2, t3;
 create table t1 (a int);
 insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -721,7 +721,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t3	index	a	a	5	NULL	30000	Using index
+2	MATERIALIZED	t3	index	a	a	5	NULL	30000	Using index
 select count(a) from t2 where a in ( SELECT  a FROM t3);
 count(a)
 1000
@@ -880,7 +880,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t4	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t4	ALL	NULL	NULL	NULL	NULL	2	
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);

mysql-test/r/subselect_sj_jcl6.result

@@ -90,7 +90,7 @@ 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	
 1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join Buffer (flAt, BNL join)
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join Buffer (incrementAl, BNL join)
-2	SUBQUERY	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
+2	MATERIALIZED	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join (`test`.`t2` `A` join `test`.`t2` `B`) on((<in_optimizer>(`test`.`B`.`A`,`test`.`B`.`A` in ( <mAteriAlize> (select `test`.`t10`.`pk` from `test`.`t10` ), <primAry_index_lookup>(`test`.`B`.`A` in <temporAry tABle> on distinct_key where ((`test`.`B`.`A` = `<suBquery2>`.`pk`))))) And (`test`.`A`.`A` = `test`.`t1`.`A`))) where 1
 t2 should be wrapped into OJ-nest, so we have "t1 LJ (t2 J t10)"
@@ -99,7 +99,7 @@ select * from t1 left join t2 on (t2.A= t1.A And t2.A in (select pk from t10));
 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	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join Buffer (flAt, BNL join)
-2	SUBQUERY	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
+2	MATERIALIZED	t10	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join `test`.`t2` on((<in_optimizer>(`test`.`t2`.`A`,`test`.`t2`.`A` in ( <mAteriAlize> (select `test`.`t10`.`pk` from `test`.`t10` ), <primAry_index_lookup>(`test`.`t2`.`A` in <temporAry tABle> on distinct_key where ((`test`.`t2`.`A` = `<suBquery2>`.`pk`))))) And (`test`.`t2`.`A` = `test`.`t1`.`A`))) where 1
 we shouldn't flatten if we're going to get a join of > MAX_TABLES.
@@ -737,8 +737,8 @@ FROM it1 LEFT JOIN it2 ON it2.datetime_key);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	11	
 1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	it1	index	NULL	int_key	4	NULL	2	Using index
-2	SUBQUERY	it2	ALL	int_key,datetime_key	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	it1	index	NULL	int_key	4	NULL	2	Using index
+2	MATERIALIZED	it2	ALL	int_key,datetime_key	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
 DROP TABLE ot1, it1, it2;
 # End of BUG#38075
 #
@@ -811,7 +811,7 @@ EXPLAIN EXTENDED SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk
 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>	eq_ref	distinct_key	distinct_key	13	func,func	1	100.00	
-2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
+2	MATERIALIZED	t2	range	PRIMARY	PRIMARY	4	NULL	2	100.00	Using index condition; Rowid-ordered scan
 Warnings:
 Note	1003	select `test`.`t1`.`pk` AS `pk` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`pk` > 0))
 SELECT pk FROM t1 WHERE (a, b) IN (SELECT a, b FROM t2 WHERE pk > 0);
@@ -980,7 +980,7 @@ 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	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
-2	SUBQUERY	t1	ALL	varchar_key	NULL	NULL	NULL	15	100.00	Using where
+2	MATERIALIZED	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_key` < 'n') xor `test`.`t1`.`pk`))
 SELECT varchar_nokey
@@ -1063,8 +1063,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
 1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	14	func	1	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	14	func	1	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
+3	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1286,8 +1286,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	<subquery3>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	C	ALL	NULL	NULL	NULL	NULL	3	
-3	SUBQUERY	D	ALL	NULL	NULL	NULL	NULL	3	
+2	MATERIALIZED	C	ALL	NULL	NULL	NULL	NULL	3	
+3	MATERIALIZED	D	ALL	NULL	NULL	NULL	NULL	3	
 drop table t1, t2;
 # 
 # BUG#784441: Abort on semijoin with a view as the inner table
@@ -1302,7 +1302,7 @@ SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	<derived3>	system	NULL	NULL	NULL	NULL	1	
+2	MATERIALIZED	<derived3>	system	NULL	NULL	NULL	NULL	1	
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
 a	a
@@ -1397,8 +1397,8 @@ explain select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	2	
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 select * from t3 where t3.b in (select t2.b from t1 left join t2 on t1.a=t2.a);
 b
 drop table t1, t2, t3;
@@ -2001,8 +2001,8 @@ SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = 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	<subquery2>	eq_ref	distinct_key	distinct_key	5	func	1	
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
-2	SUBQUERY	t2	ref	b	b	4	test.t3.a	1	Using index
+2	MATERIALIZED	t3	ALL	NULL	NULL	NULL	NULL	13	Using where
+2	MATERIALIZED	t2	ref	b	b	4	test.t3.a	1	Using index
 SELECT * FROM t1 WHERE (a) IN (SELECT a FROM t2 JOIN t3 ON b = a);
 a
 19

mysql-test/r/subselect_sj_nonmerged.result

@@ -10,7 +10,7 @@ explain select * from t0 where a in (select max(a) from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	1	
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	
 select * from t0 where a in (select max(a) from t1);
 a
 9
@@ -42,23 +42,23 @@ explain select * from t3 where a in (select max(t2.a) from t1, t2 group by t2.b)
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using where
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 # Compare to this which really will have 50 record combinations:
 explain select * from t3 where a in (select max(t2.a) from t1, t2 group by t2.b, t1.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	Using where
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 # Outer joins also work:
 explain select * from t3 
 where a in (select max(t2.a) from t1 left join t2 on t1.a=t2.a group by t2.b, t1.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	50	Using where
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	8	<subquery2>.max(t2.a)	1	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using temporary
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using temporary
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using where
 create table t4 (a int, b int, filler char(20), unique key(a,b));
 insert into t4 select A.a + 10*B.a, A.a + 10*B.a, 'filler' from t0 A, t0 B;
 explain select * from t0, t4 where 
@@ -67,8 +67,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	t4	ALL	a	NULL	NULL	NULL	100	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	5	test.t4.a	1	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 insert into t4 select 100 + (B.a *100 + A.a), 100 + (B.a*100 + A.a), 'filler' from t4 A, t0 B;
 explain select * from t4 where 
 t4.a in (select max(t2.a) from t1, t2 group by t2.b) and 
@@ -77,10 +77,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	5	Using where
 1	PRIMARY	<subquery3>	ALL	distinct_key	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t4	ref	a	a	10	<subquery2>.max(t2.a),<subquery3>.max(t2.a)	12	
-3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
-3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	5	Using temporary
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 drop table t1,t2,t3,t4;
 drop table t0;
 #
@@ -114,6 +114,6 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	1	Using where
 1	PRIMARY	X	ref	a	a	5	<subquery2>.max(a)	1	Using index
 1	PRIMARY	Y	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
-2	SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	
+2	MATERIALIZED	t0	ALL	NULL	NULL	NULL	NULL	10	
 drop table t0, t1;
 set optimizer_switch=@save_optimizer_switch;

mysql-test/suite/pbxt/r/subselect.result

@@ -2839,7 +2839,7 @@ explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FR
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	10	func,func	1	100.00	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
+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` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
 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;
@@ -3432,7 +3432,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 ALTER TABLE t1 ADD INDEX(a);
 SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
 a	b
@@ -3444,7 +3444,7 @@ 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	Using where
 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
+2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
 DROP TABLE t1;
 create table t1( f1 int,f2 int);
 insert into t1 values (1,1),(2,2);

sql/sql_lex.cc

@@ -3527,20 +3527,58 @@ void st_select_lex::set_explain_type()
   SELECT_LEX *first= master_unit()->first_select();
   /* drop UNCACHEABLE_EXPLAIN, because it is for internal usage only */
   uint8 is_uncacheable= (uncacheable & ~UNCACHEABLE_EXPLAIN);
+  
+  bool using_materialization= FALSE;
+  Item_subselect *parent_item;
+  if ((parent_item= master_unit()->item) &&
+      parent_item->substype() == Item_subselect::IN_SUBS)
+  {
+    Item_in_subselect *in_subs= (Item_in_subselect*)parent_item;
+    /*
+      Surprisingly, in_subs->is_set_strategy() can return FALSE here,
+      even for the last invocation of this function for the select.
+    */
+    if (in_subs->test_strategy(SUBS_MATERIALIZATION))
+      using_materialization= TRUE;
+  }
 
-  type= ((&master_unit()->thd->lex->select_lex == this) ?
-         (is_primary ? "PRIMARY" : "SIMPLE"):    
-         ((this == first) ?
-          ((linkage == DERIVED_TABLE_TYPE) ?
-           "DERIVED" :
-           ((is_uncacheable & UNCACHEABLE_DEPENDENT) ?
-            "DEPENDENT SUBQUERY" :
-            (is_uncacheable ? "UNCACHEABLE SUBQUERY" :
-             "SUBQUERY"))) :
-          ((is_uncacheable & UNCACHEABLE_DEPENDENT) ?
-           "DEPENDENT UNION":
-           is_uncacheable ? "UNCACHEABLE UNION":
-           "UNION")));
+  if (&master_unit()->thd->lex->select_lex == this)
+  {
+     type= is_primary ? "PRIMARY" : "SIMPLE";
+  }
+  else
+  {
+    if (this == first)
+    {
+      /* If we're a direct child of a UNION, we're the first sibling there */
+      if (linkage == DERIVED_TABLE_TYPE)
+        type= "DERIVED";
+      else if (using_materialization)
+        type= "MATERIALIZED";
+      else
+      {
+         if (is_uncacheable & UNCACHEABLE_DEPENDENT)
+           type= "DEPENDENT SUBQUERY";
+         else
+         {
+           type= is_uncacheable? "UNCACHEABLE SUBQUERY" :
+                                 "SUBQUERY";
+         }
+      }
+    }
+    else
+    {
+      /* This a non-first sibling in UNION */
+      if (is_uncacheable & UNCACHEABLE_DEPENDENT)
+        type= "DEPENDENT UNION";
+      else if (using_materialization)
+        type= "MATERIALIZED UNION";
+      else
+      {
+        type= is_uncacheable ? "UNCACHEABLE UNION": "UNION";
+      }
+    }
+  }
   options|= SELECT_DESCRIBE;
 }
 

sql/sql_select.cc

@@ -20642,7 +20642,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
       /* id */
       item_list.push_back(new Item_uint((uint32)select_id));
       /* select_type */
-      const char* stype= printing_materialize_nest? "SUBQUERY" : 
+      const char* stype= printing_materialize_nest? "MATERIALIZED" : 
                                                     join->select_lex->type;
       item_list.push_back(new Item_string(stype, strlen(stype), cs));