From da5214831d3d0f0880b4068a06ce062ca703293f Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Thu, 17 May 2012 13:46:05 +0300
Subject: [PATCH 1/5] Fix for bug lp:944706, task MDEV-193

The patch enables back constant subquery execution during
query optimization after it was disabled during the development
of MWL#89 (cost-based choice of IN-TO-EXISTS vs MATERIALIZATION).

The main idea is that constant subqueries are allowed to be executed
during optimization if their execution is not expensive.

The approach is as follows:
- Constant subqueries are recursively optimized in the beginning of
  JOIN::optimize of the outer query. This is done by the new method
  JOIN::optimize_constant_subqueries(). This is done so that the cost
  of executing these queries can be estimated.
- Optimization of the outer query proceeds normally. During this phase
  the optimizer may request execution of non-expensive constant subqueries.
  Each place where the optimizer may potentially execute an expensive
  expression is guarded with the predicate Item::is_expensive().
- The implementation of Item_subselect::is_expensive has been extended
  to use the number of examined rows (estimated by the optimizer) as a
  way to determine whether the subquery is expensive or not.
- The new system variable "expensive_subquery_limit" controls how many
  examined rows are considered to be not expensive. The default is 100.

In addition, multiple changes were needed to make this solution work
in the light of the changes made by MWL#89. These changes were needed
to fix various crashes and wrong results, and legacy bugs discovered
during development.
---
 mysql-test/r/explain.result                 |  12 +-
 mysql-test/r/group_min_max.result           |  22 +--
 mysql-test/r/join_outer.result              |   4 +-
 mysql-test/r/join_outer_jcl6.result         |   4 +-
 mysql-test/r/key.result                     |   4 +-
 mysql-test/r/limit_rows_examined.result     |   2 +-
 mysql-test/r/myisam_mrr.result              |   4 +-
 mysql-test/r/mysqld--help.result            |   5 +
 mysql-test/r/subselect.result               |  92 +++++++----
 mysql-test/r/subselect3.result              |   2 +-
 mysql-test/r/subselect3_jcl6.result         |   2 +-
 mysql-test/r/subselect4.result              |  35 ++--
 mysql-test/r/subselect_cache.result         |   8 +-
 mysql-test/r/subselect_innodb.result        |   6 +-
 mysql-test/r/subselect_mat.result           |  36 ++---
 mysql-test/r/subselect_mat_cost_bugs.result |   4 +-
 mysql-test/r/subselect_no_mat.result        |  98 ++++++++----
 mysql-test/r/subselect_no_opts.result       |  98 ++++++++----
 mysql-test/r/subselect_no_scache.result     |  92 +++++++----
 mysql-test/r/subselect_no_semijoin.result   | 102 ++++++++----
 mysql-test/r/subselect_sj_mat.result        |  18 +--
 mysql-test/suite/sys_vars/r/all_vars.result |   1 +
 mysql-test/t/subselect.test                 |  32 ++++
 mysql-test/t/subselect4.test                |   8 +
 sql/item.h                                  |  12 +-
 sql/item_cmpfunc.cc                         |  10 +-
 sql/item_cmpfunc.h                          |   4 +-
 sql/item_strfunc.h                          |   2 +-
 sql/item_subselect.cc                       |  42 +++++
 sql/item_subselect.h                        |   8 +-
 sql/opt_subselect.cc                        |  47 +++++-
 sql/sql_class.h                             |   1 +
 sql/sql_delete.cc                           |   2 +-
 sql/sql_lex.cc                              |  26 ++-
 sql/sql_lex.h                               |   7 +-
 sql/sql_select.cc                           | 169 +++++++++++++-------
 sql/sql_select.h                            |   3 +
 sql/sql_update.cc                           |   2 +-
 sql/sys_vars.cc                             |   7 +-
 sql/table.cc                                |   8 +-
 40 files changed, 714 insertions(+), 327 deletions(-)

diff --git a/mysql-test/r/explain.result b/mysql-test/r/explain.result
index a6fa21ad800..863526c637e 100644
--- a/mysql-test/r/explain.result
+++ b/mysql-test/r/explain.result
@@ -260,7 +260,7 @@ FLUSH TABLES;
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT 1 FROM t1 t JOIN t2 WHERE b <= 1 AND t.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	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 DROP TABLE t1, t2;
 #
 # Bug #48573: difference of index selection between rpm binary and
@@ -287,7 +287,7 @@ 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	
 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
-2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
+2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
  WHERE 1 > ALL((SELECT t1.f1 FROM t1 RIGHT OUTER JOIN t1 a
@@ -297,12 +297,12 @@ EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
-2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
+2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
-2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
+2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	
 DEALLOCATE PREPARE stmt;
 PREPARE stmt FROM
 'EXPLAIN SELECT 1 FROM t1
@@ -313,12 +313,12 @@ EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
-2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
+2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
-2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
+2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1;
 End of 5.1 tests.
diff --git a/mysql-test/r/group_min_max.result b/mysql-test/r/group_min_max.result
index c5c5f65df29..95caa6853b8 100644
--- a/mysql-test/r/group_min_max.result
+++ b/mysql-test/r/group_min_max.result
@@ -2398,12 +2398,12 @@ EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE EXISTS
 (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	t1_outer	index	NULL	a	10	NULL	15	Using index
-2	SUBQUERY	t1	index	NULL	a	10	NULL	1	Using index
+2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	index	NULL	a	10	NULL	15	Using index
-2	SUBQUERY	t1	range	NULL	a	5	NULL	8	Using index for group-by
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -2419,9 +2419,9 @@ EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2
 ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) 
 AND t1_outer1.b = t1_outer2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer1	ref	a	a	5	const	2	Using where; Using index
+1	PRIMARY	t1_outer1	ref	a	a	5	const	1	Using where; Using index
 1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer (flat, BNL join)
-2	SUBQUERY	t1	range	NULL	a	5	NULL	8	Using index for group-by
+2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
 FROM t1 AS t1_outer) x2 FROM t1 AS t1_outer2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -2756,8 +2756,8 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Using where; Using index
-x	x	x	x	x	x	x	x	x	Using where; Using index
+x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
 NULL
@@ -2828,8 +2828,8 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Using where; Using index
-x	x	x	x	x	x	x	x	x	Using where; Using index
+x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
 NULL
@@ -2907,8 +2907,8 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Using where; Using index
-x	x	x	x	x	x	x	x	x	Using where; Using index
+x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
 NULL
diff --git a/mysql-test/r/join_outer.result b/mysql-test/r/join_outer.result
index ebe8255fd8b..49a6a0d76d3 100644
--- a/mysql-test/r/join_outer.result
+++ b/mysql-test/r/join_outer.result
@@ -1871,10 +1871,10 @@ EXPLAIN EXTENDED
 SELECT t2.a FROM t1 LEFT JOIN t2 ON (6) IN (SELECT a FROM t3);
 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	1	100.00	Using where
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
 2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where 1
+Note	1003	select NULL AS `a` from `test`.`t2` where 1
 DROP TABLE t1,t2,t3;
 #
 # LP bug #817384 Wrong result with outer join + subquery in ON
diff --git a/mysql-test/r/join_outer_jcl6.result b/mysql-test/r/join_outer_jcl6.result
index 3d0e4cbfc79..d1333136f1c 100644
--- a/mysql-test/r/join_outer_jcl6.result
+++ b/mysql-test/r/join_outer_jcl6.result
@@ -1882,10 +1882,10 @@ EXPLAIN EXTENDED
 SELECT t2.a FROM t1 LEFT JOIN t2 ON (6) IN (SELECT a FROM t3);
 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	1	100.00	Using where
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
 2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where 1
+Note	1003	select NULL AS `a` from `test`.`t2` where 1
 DROP TABLE t1,t2,t3;
 #
 # LP bug #817384 Wrong result with outer join + subquery in ON
diff --git a/mysql-test/r/key.result b/mysql-test/r/key.result
index 4035f61e36b..e215caadb1c 100644
--- a/mysql-test/r/key.result
+++ b/mysql-test/r/key.result
@@ -598,8 +598,8 @@ VALUES
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	index	NULL	a	10	NULL	15	Using index
-2	SUBQUERY	t1	range	NULL	a	5	NULL	8	Using index for group-by
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 SELECT 1 as RES FROM t1 AS t1_outer WHERE 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
 RES
diff --git a/mysql-test/r/limit_rows_examined.result b/mysql-test/r/limit_rows_examined.result
index f4242f17a14..3a5212818ef 100644
--- a/mysql-test/r/limit_rows_examined.result
+++ b/mysql-test/r/limit_rows_examined.result
@@ -679,7 +679,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	Using temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	Distinct
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	3	
 SELECT DISTINCT a AS field1 FROM t1, t2 
 WHERE EXISTS (SELECT c FROM t3 LEFT JOIN t2 ON b = d) 
 HAVING field1 > 'aaa' LIMIT ROWS EXAMINED 20;
diff --git a/mysql-test/r/myisam_mrr.result b/mysql-test/r/myisam_mrr.result
index d4b25f25d40..03d212dbc04 100644
--- a/mysql-test/r/myisam_mrr.result
+++ b/mysql-test/r/myisam_mrr.result
@@ -349,10 +349,10 @@ WHERE t2.int_key IS NULL
 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	
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 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 dual where exists(select `test`.`t2`.`pk` from `test`.`t2` where isnull(`test`.`t2`.`int_key`))
+Note	1003	select min(`test`.`t1`.`pk`) AS `MIN(t1.pk)` from `test`.`t1` where 0
 DROP TABLE t1, t2;
 #
 # BUG#42048 Discrepancy between MyISAM and Maria's ICP implementation
diff --git a/mysql-test/r/mysqld--help.result b/mysql-test/r/mysqld--help.result
index fcadee7aced..ad55bfa3003 100644
--- a/mysql-test/r/mysqld--help.result
+++ b/mysql-test/r/mysqld--help.result
@@ -159,6 +159,10 @@ The following options may be given as the first argument:
  Enable the event scheduler. Possible values are ON, OFF,
  and DISABLED (keep the event scheduler completely
  deactivated, it cannot be activated run-time)
+ --expensive-subquery-limit=# 
+ The maximum number of rows a subquery may examine in
+ order to be executed during optimization and used for
+ constant optimization
  --expire-logs-days=# 
  If non-zero, binary logs will be purged after
  expire_logs_days days; possible purges happen at startup
@@ -885,6 +889,7 @@ delayed-queue-size 1000
 div-precision-increment 4
 engine-condition-pushdown FALSE
 event-scheduler OFF
+expensive-subquery-limit 100
 expire-logs-days 0
 external-locking FALSE
 extra-max-connections 1
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index dca872f0bbd..a75d0f960af 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -371,12 +371,12 @@ INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1');
 EXPLAIN EXTENDED SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
+1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
-2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
+2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -517,6 +517,7 @@ ERROR 21000: Subquery returns more than 1 row
 show warnings;
 Level	Code	Message
 Error	1242	Subquery returns more than 1 row
+Error	1028	Sort aborted: Subquery returns more than 1 row
 drop table t1;
 create table t1 (a int);
 insert into t1 values (1),(2),(3);
@@ -547,11 +548,7 @@ SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT
 numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
-2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
-Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
+ERROR 21000: Subquery returns more than 1 row
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 ERROR 21000: Subquery returns more than 1 row
 EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
@@ -1675,34 +1672,34 @@ select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 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
@@ -1764,7 +1761,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 'e' AS `s1` from dual where <nop>(<in_optimizer>('f',(<min>(select 'e' from dual union select 'e' from dual) < 'f')))
+Note	1003	select 'e' AS `s1` from dual where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
@@ -3099,7 +3096,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
              ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3111,7 +3108,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3727,8 +3724,8 @@ explain select * from t1 where not exists
 ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 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	t11	system	NULL	NULL	NULL	NULL	0	const row not found
-3	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
 CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
@@ -4198,8 +4195,8 @@ CREATE TABLE t1 (a int, b int, KEY (a));
 INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
@@ -4626,7 +4623,7 @@ 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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <nop>(<in_optimizer>(1,((select max(`test`.`t1`.`a1`) from `test`.`t1`) > 1)))
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 SELECT 1 FROM t1 WHERE 1 < SOME (SELECT a1 FROM t1);
 1
 1
@@ -5960,7 +5957,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 DROP TABLE t1;
 #
 # BUG#12616253 - WRONG RESULT WITH EXISTS(SUBQUERY) (MISSING ROWS)
@@ -6121,7 +6118,7 @@ set optimizer_switch=@tmp_optimizer_switch;
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 
 DROP TABLE t1;
 #
@@ -6562,5 +6559,40 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 COUNT(f1)	f4
 0	0
 drop table t1,t2;
+#
+# LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+# precomputed and thus not part of optimization
+#
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+field
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
+1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
+1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+MAX( alias2.a )
+Arden-Arcade
+drop table t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/r/subselect3.result b/mysql-test/r/subselect3.result
index 014ff5b5810..b33e7e113f2 100644
--- a/mysql-test/r/subselect3.result
+++ b/mysql-test/r/subselect3.result
@@ -1479,7 +1479,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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`))))))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where 1
 SELECT * FROM t1
 WHERE (
 ( SELECT a FROM t2 WHERE a = 9 ),
diff --git a/mysql-test/r/subselect3_jcl6.result b/mysql-test/r/subselect3_jcl6.result
index a62048db506..4660cd60603 100644
--- a/mysql-test/r/subselect3_jcl6.result
+++ b/mysql-test/r/subselect3_jcl6.result
@@ -1489,7 +1489,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 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`))))))))
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where 1
 SELECT * FROM t1
 WHERE (
 ( SELECT a FROM t2 WHERE a = 9 ),
diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result
index 82360f9fe9f..c17ffe75282 100644
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -562,7 +562,7 @@ WHERE f3 = (
 SELECT t1.f3 FROM t1
 WHERE ( t1.f10 ) IN ( SELECT 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
@@ -577,7 +577,7 @@ WHERE f3 = (
 SELECT f3 FROM t1
 WHERE ( f10, f10 ) IN ( SELECT 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	8	func,func	1	
 3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	
@@ -1220,6 +1220,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	SUBQUERY	SQ1_t1	index	NULL	f4	5	NULL	2	Using index; Using temporary
 3	SUBQUERY	SQ1_t3	index	f4	f4	5	NULL	2	Using where; Using index; Using join buffer (flat, BNL join)
+SELECT * FROM t1 WHERE
+(SELECT f2 FROM t2
+WHERE f4 <= ALL
+(SELECT max(SQ1_t1.f4)
+FROM t3 AS SQ1_t1 JOIN t3 AS SQ1_t3 ON SQ1_t3.f4
+GROUP BY SQ1_t1.f4));
+ERROR 21000: Subquery returns more than 1 row
 drop table t1, t2, t3;
 #
 # BUG#52317: Assertion failing in Field_varstring::store() 
@@ -1250,8 +1257,7 @@ FROM t2 JOIN t1 ON t1.f3
 WHERE ('v') IN (SELECT f4 FROM t2)
 GROUP BY f9;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
@@ -1267,8 +1273,7 @@ FROM t2 JOIN t1 ON t1.f3
 WHERE ('v') IN (SELECT f4 FROM t2)
 ORDER BY f9;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
@@ -1277,7 +1282,7 @@ FROM t2 JOIN t1 ON t1.f3
 WHERE ('v') IN (SELECT f4 FROM t2)
 ORDER BY f9;
 COUNT(t2.f3)	f9
-0	2
+0	NULL
 EXPLAIN
 SELECT COUNT(t2.f3),
 (SELECT t2.f1 FROM t1 limit 1) AS f9
@@ -1285,8 +1290,7 @@ FROM t2 JOIN t1
 WHERE ('v') IN (SELECT f4 FROM t2)
 GROUP BY f9;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
@@ -1302,8 +1306,7 @@ FROM t2 JOIN t1
 WHERE ('v') IN (SELECT f4 FROM t2)
 ORDER BY f9;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
@@ -1325,7 +1328,7 @@ EXPLAIN
 SELECT (SELECT f1 FROM t1) AS field1 FROM t2 GROUP BY field1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f1 FROM t1) AS field1 FROM t2 GROUP BY field1;
 field1
 NULL
@@ -1333,7 +1336,7 @@ EXPLAIN
 SELECT (SELECT f1 FROM t1) AS field1 FROM t2 ORDER BY field1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f1 FROM t1) AS field1 FROM t2 ORDER BY field1;
 field1
 NULL
@@ -1631,7 +1634,7 @@ SET SESSION optimizer_switch='in_to_exists=on,materialization=off';
 EXPLAIN
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
 2	DEPENDENT SUBQUERY	t2	ref_or_null	f10	f10	10	const,const	2	Using where; Using index
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
@@ -1852,8 +1855,8 @@ GROUP BY 1, 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	system	NULL	NULL	NULL	NULL	1	Using temporary; Using filesort
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
-2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	MATERIALIZED	t1	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 PREPARE st1 FROM "
 SELECT t2.f1, (SELECT f2 FROM t1 WHERE (7) IN (SELECT f1 FROM t1))
 FROM t2 JOIN t3 ON t3.f4 = t2.f4
diff --git a/mysql-test/r/subselect_cache.result b/mysql-test/r/subselect_cache.result
index e38e8b42e9a..7bd10dc11a6 100644
--- a/mysql-test/r/subselect_cache.result
+++ b/mysql-test/r/subselect_cache.result
@@ -486,9 +486,9 @@ Handler_read_key	7
 Handler_read_last	0
 Handler_read_next	0
 Handler_read_prev	0
-Handler_read_rnd	10
+Handler_read_rnd	0
 Handler_read_rnd_deleted	0
-Handler_read_rnd_next	42
+Handler_read_rnd_next	31
 set optimizer_switch='subquery_cache=off';
 flush status;
 select a from t1 ORDER BY (select d from t2 where b=c);
@@ -514,9 +514,9 @@ Handler_read_key	0
 Handler_read_last	0
 Handler_read_next	0
 Handler_read_prev	0
-Handler_read_rnd	10
+Handler_read_rnd	0
 Handler_read_rnd_deleted	0
-Handler_read_rnd_next	72
+Handler_read_rnd_next	61
 set optimizer_switch='subquery_cache=on';
 #single value subquery test (distinct ORDER BY)
 flush status;
diff --git a/mysql-test/r/subselect_innodb.result b/mysql-test/r/subselect_innodb.result
index 60faea8853f..bbaf26e6249 100644
--- a/mysql-test/r/subselect_innodb.result
+++ b/mysql-test/r/subselect_innodb.result
@@ -272,8 +272,8 @@ FROM t2
 WHERE (SELECT DISTINCT b FROM t3) > 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	Using where; Using index
-2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	1	Using temporary
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	0	Using temporary
 SELECT *
 FROM t1
 WHERE t1.a = (
@@ -301,7 +301,7 @@ 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	
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	1	
 SELECT MAX( f1 ) FROM t2
 WHERE f2 >= (
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 86442df1e8b..323da97cc89 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -1152,8 +1152,8 @@ create table t2 (b1 int);
 insert into t1 values (5);
 explain select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	MATERIALIZED	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 min(a1)
 NULL
@@ -1162,8 +1162,8 @@ 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 max(b1) from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 min(a1)
 NULL
@@ -1171,8 +1171,8 @@ set @@optimizer_switch=@optimizer_switch_local_default;
 set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	MATERIALIZED	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
 NULL
@@ -1181,16 +1181,16 @@ set @@optimizer_switch='materialization=off,in_to_exists=on';
 # with MariaDB and MWL#90, this particular case is solved:
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
 NULL
 # but when we go around MWL#90 code, the problem still shows up:
 explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 min(a1)
 NULL
@@ -1932,7 +1932,7 @@ WHERE s2.d = s1.e AND s1.e = (SELECT MAX(e) FROM t2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t2	index	NULL	c	5	NULL	8	Using where; Using index
-2	MATERIALIZED	s2	ref	d	d	4	const	1	Using where; Using index
+2	MATERIALIZED	s2	ref	d	d	4	const	2	Using where; Using index
 2	MATERIALIZED	s1	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	8	
 SELECT a, c FROM t1, t2
@@ -1951,8 +1951,8 @@ WHERE s2.d = s1.e AND s1.e = (SELECT MAX(e) FROM t2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t2	index	NULL	c	5	NULL	8	Using where; Using index
-2	MATERIALIZED	s2	ref	d	d	4	const	1	Using where; Using index
-2	MATERIALIZED	s1	hash_ALL	NULL	#hash#$hj	5	test.s2.d	8	Using where; Using join buffer (flat, BNLH join)
+2	MATERIALIZED	s2	ref	d	d	4	const	2	Using where; Using index
+2	MATERIALIZED	s1	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	8	
 SELECT a, c FROM t1, t2
 WHERE (a, c) IN (SELECT s1.b, s1.c FROM t2 AS s1, t2 AS s2
@@ -2153,7 +2153,7 @@ set @@optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_
 EXPLAIN
 SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
@@ -2222,10 +2222,10 @@ NULL
 EXPLAIN EXTENDED
 SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	index	NULL	b	5	NULL	2	100.00	Using index
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where <expr_cache><9>(<in_optimizer>(9,9 in ( <materialize> (select `test`.`t2`.`a` from `test`.`t2` ), <primary_index_lookup>(9 in <temporary table> on distinct_key where ((9 = `<subquery2>`.`a`))))))
+Note	1003	select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where 0
 set @@optimizer_switch='materialization=off,in_to_exists=on,semijoin=off';
 SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
 max_res
@@ -2233,10 +2233,10 @@ NULL
 EXPLAIN EXTENDED
 SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	index	NULL	b	5	NULL	2	100.00	Using index
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where <expr_cache><9>(<in_optimizer>(9,<exists>(select `test`.`t2`.`a` from `test`.`t2` where (9 = `test`.`t2`.`a`))))
+Note	1003	select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where 0
 DROP TABLE t1,t2;
 #
 # LPBUG#825095: Wrong result with materialization and NOT IN with 2 expressions
diff --git a/mysql-test/r/subselect_mat_cost_bugs.result b/mysql-test/r/subselect_mat_cost_bugs.result
index 96f904c722c..e656bf8e22f 100644
--- a/mysql-test/r/subselect_mat_cost_bugs.result
+++ b/mysql-test/r/subselect_mat_cost_bugs.result
@@ -124,7 +124,7 @@ FROM t3 RIGHT JOIN t1 ON t1.pk = t3.f1
 WHERE t3.f3 OR ( 3 ) IN ( SELECT f2 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	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT t1.*
 FROM t3 RIGHT JOIN t1 ON t1.pk = t3.f1
 WHERE t3.f3 OR ( 3 ) IN ( SELECT f2 FROM t2 );
@@ -148,7 +148,7 @@ FROM t2 GROUP BY f1
 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; Using filesort
+3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 drop table t1, t2, t3;
 #
 # LP BUG#715034 Item_sum_distinct::clear(): Assertion `tree != 0' failed
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index d5c7084c48d..507c8741d25 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -378,12 +378,12 @@ INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1');
 EXPLAIN EXTENDED SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
+1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
-2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
+2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -524,6 +524,7 @@ ERROR 21000: Subquery returns more than 1 row
 show warnings;
 Level	Code	Message
 Error	1242	Subquery returns more than 1 row
+Error	1028	Sort aborted: Subquery returns more than 1 row
 drop table t1;
 create table t1 (a int);
 insert into t1 values (1),(2),(3);
@@ -554,11 +555,7 @@ SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT
 numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
-2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
-Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
+ERROR 21000: Subquery returns more than 1 row
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 ERROR 21000: Subquery returns more than 1 row
 EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
@@ -1682,34 +1679,34 @@ select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 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
@@ -1771,7 +1768,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 'e' AS `s1` from dual where <nop>(<in_optimizer>('f',(<min>(select 'e' from dual union select 'e' from dual) < 'f')))
+Note	1003	select 'e' AS `s1` from dual where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
@@ -3105,7 +3102,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
              ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3117,7 +3114,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3731,8 +3728,8 @@ explain select * from t1 where not exists
 ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 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	t11	system	NULL	NULL	NULL	NULL	0	const row not found
-3	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
 CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
@@ -4202,8 +4199,8 @@ CREATE TABLE t1 (a int, b int, KEY (a));
 INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
@@ -4531,13 +4528,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 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 min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`))))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 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 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`))))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 0
 SET join_cache_level=@save_join_cache_level;
 DROP TABLE t1;
 #
@@ -4628,7 +4625,7 @@ 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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <nop>(<in_optimizer>(1,((select max(`test`.`t1`.`a1`) from `test`.`t1`) > 1)))
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 SELECT 1 FROM t1 WHERE 1 < SOME (SELECT a1 FROM t1);
 1
 1
@@ -5961,7 +5958,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 DROP TABLE t1;
 #
 # BUG#12616253 - WRONG RESULT WITH EXISTS(SUBQUERY) (MISSING ROWS)
@@ -6120,7 +6117,7 @@ set optimizer_switch=@tmp_optimizer_switch;
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 
 DROP TABLE t1;
 #
@@ -6561,6 +6558,41 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 COUNT(f1)	f4
 0	0
 drop table t1,t2;
+#
+# LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+# precomputed and thus not part of optimization
+#
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+field
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
+1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
+1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+MAX( alias2.a )
+Arden-Arcade
+drop table t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 7b44b1a1f5d..9ca09ac061c 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -374,12 +374,12 @@ INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1');
 EXPLAIN EXTENDED SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
+1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
-2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
+2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -520,6 +520,7 @@ ERROR 21000: Subquery returns more than 1 row
 show warnings;
 Level	Code	Message
 Error	1242	Subquery returns more than 1 row
+Error	1028	Sort aborted: Subquery returns more than 1 row
 drop table t1;
 create table t1 (a int);
 insert into t1 values (1),(2),(3);
@@ -550,11 +551,7 @@ SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT
 numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
-2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
-Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
+ERROR 21000: Subquery returns more than 1 row
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 ERROR 21000: Subquery returns more than 1 row
 EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
@@ -1678,34 +1675,34 @@ select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 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
@@ -1767,7 +1764,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 'e' AS `s1` from dual where <nop>(<in_optimizer>('f',(<min>(select 'e' from dual union select 'e' from dual) < 'f')))
+Note	1003	select 'e' AS `s1` from dual where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
@@ -3101,7 +3098,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
              ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3113,7 +3110,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3727,8 +3724,8 @@ explain select * from t1 where not exists
 ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 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	t11	system	NULL	NULL	NULL	NULL	0	const row not found
-3	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
 CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
@@ -4198,8 +4195,8 @@ CREATE TABLE t1 (a int, b int, KEY (a));
 INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
@@ -4527,13 +4524,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 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 min(`test`.`t1`.`a`) from `test`.`t1` group by `test`.`t1`.`a` having (1 = <ref_null_helper>(min(`test`.`t1`.`a`)))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 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 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`)))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 0
 SET join_cache_level=@save_join_cache_level;
 DROP TABLE t1;
 #
@@ -4624,7 +4621,7 @@ 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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <nop>(<in_optimizer>(1,((select max(`test`.`t1`.`a1`) from `test`.`t1`) > 1)))
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 SELECT 1 FROM t1 WHERE 1 < SOME (SELECT a1 FROM t1);
 1
 1
@@ -5957,7 +5954,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 DROP TABLE t1;
 #
 # BUG#12616253 - WRONG RESULT WITH EXISTS(SUBQUERY) (MISSING ROWS)
@@ -6116,7 +6113,7 @@ set optimizer_switch=@tmp_optimizer_switch;
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 
 DROP TABLE t1;
 #
@@ -6557,6 +6554,41 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 COUNT(f1)	f4
 0	0
 drop table t1,t2;
+#
+# LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+# precomputed and thus not part of optimization
+#
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+field
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
+1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
+1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+MAX( alias2.a )
+Arden-Arcade
+drop table t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index 9b24af0dc3a..f7a8e8efd01 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -377,12 +377,12 @@ INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1');
 EXPLAIN EXTENDED SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
+1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
-2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
+2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -523,6 +523,7 @@ ERROR 21000: Subquery returns more than 1 row
 show warnings;
 Level	Code	Message
 Error	1242	Subquery returns more than 1 row
+Error	1028	Sort aborted: Subquery returns more than 1 row
 drop table t1;
 create table t1 (a int);
 insert into t1 values (1),(2),(3);
@@ -553,11 +554,7 @@ SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT
 numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
-2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
-Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
+ERROR 21000: Subquery returns more than 1 row
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 ERROR 21000: Subquery returns more than 1 row
 EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
@@ -1681,34 +1678,34 @@ select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 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
@@ -1770,7 +1767,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 'e' AS `s1` from dual where <nop>(<in_optimizer>('f',(<min>(select 'e' from dual union select 'e' from dual) < 'f')))
+Note	1003	select 'e' AS `s1` from dual where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
@@ -3105,7 +3102,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
              ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3117,7 +3114,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3733,8 +3730,8 @@ explain select * from t1 where not exists
 ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 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	t11	system	NULL	NULL	NULL	NULL	0	const row not found
-3	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
 CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
@@ -4204,8 +4201,8 @@ CREATE TABLE t1 (a int, b int, KEY (a));
 INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
@@ -4632,7 +4629,7 @@ 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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <nop>(<in_optimizer>(1,((select max(`test`.`t1`.`a1`) from `test`.`t1`) > 1)))
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 SELECT 1 FROM t1 WHERE 1 < SOME (SELECT a1 FROM t1);
 1
 1
@@ -5966,7 +5963,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 DROP TABLE t1;
 #
 # BUG#12616253 - WRONG RESULT WITH EXISTS(SUBQUERY) (MISSING ROWS)
@@ -6127,7 +6124,7 @@ set optimizer_switch=@tmp_optimizer_switch;
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 
 DROP TABLE t1;
 #
@@ -6568,6 +6565,41 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 COUNT(f1)	f4
 0	0
 drop table t1,t2;
+#
+# LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+# precomputed and thus not part of optimization
+#
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+field
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
+1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
+1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+MAX( alias2.a )
+Arden-Arcade
+drop table t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index ba42ff881fc..f0186c682a4 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -374,12 +374,12 @@ INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1');
 EXPLAIN EXTENDED SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
+1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
-2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
+2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	
 3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
 Warnings:
-Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
+Note	1003	select 'joce' AS `pseudo`,(select 'test' from `test`.`t8` where 1) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where 1
 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
 t8 WHERE pseudo='joce');
 ERROR 21000: Operand should contain 1 column(s)
@@ -520,6 +520,7 @@ ERROR 21000: Subquery returns more than 1 row
 show warnings;
 Level	Code	Message
 Error	1242	Subquery returns more than 1 row
+Error	1028	Sort aborted: Subquery returns more than 1 row
 drop table t1;
 create table t1 (a int);
 insert into t1 values (1),(2),(3);
@@ -550,11 +551,7 @@ SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT
 numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
-2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
-Warnings:
-Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
+ERROR 21000: Subquery returns more than 1 row
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 ERROR 21000: Subquery returns more than 1 row
 EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
@@ -1678,34 +1675,34 @@ select * from t3 where NULL >= any (select b from t2);
 a
 explain extended select * from t3 where NULL >= any (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= any (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2);
 a
 explain extended select * from t3 where NULL >= some (select b from t2);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 select * from t3 where NULL >= some (select b from t2 group by 1);
 a
 explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
 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
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
-Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(NULL) from `test`.`t2`) <= NULL)))
+Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where 0
 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
@@ -1767,7 +1764,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	t1	system	NULL	NULL	NULL	NULL	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	select 'e' AS `s1` from dual where <nop>(<in_optimizer>('f',(<min>(select 'e' from dual union select 'e' from dual) < 'f')))
+Note	1003	select 'e' AS `s1` from dual where 1
 drop table t1;
 CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
 INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
@@ -3101,7 +3098,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
              ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3113,7 +3110,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
 2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
@@ -3727,8 +3724,8 @@ explain select * from t1 where not exists
 ((select t11.i from t1 t11) union (select t12.i from t1 t12));
 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	t11	system	NULL	NULL	NULL	NULL	0	const row not found
-3	UNION	t12	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 DROP TABLE t1;
 CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
@@ -4198,8 +4195,8 @@ CREATE TABLE t1 (a int, b int, KEY (a));
 INSERT INTO t1 VALUES (1,1),(2,1);
 EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 DROP TABLE t1;
 CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
 INSERT INTO t1 VALUES
@@ -4525,15 +4522,15 @@ SET join_cache_level=0;
 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
+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>(1,1 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)`))))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 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	
-2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+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>(1,1 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)`))))))
+Note	1003	select 1 AS `1` from `test`.`t1` where 0
 SET join_cache_level=@save_join_cache_level;
 DROP TABLE t1;
 #
@@ -4624,7 +4621,7 @@ 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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
-Note	1003	select 1 AS `1` from `test`.`t1` where <nop>(<in_optimizer>(1,((select max(`test`.`t1`.`a1`) from `test`.`t1`) > 1)))
+Note	1003	select 1 AS `1` from `test`.`t1` where 1
 SELECT 1 FROM t1 WHERE 1 < SOME (SELECT a1 FROM t1);
 1
 1
@@ -5957,7 +5954,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 DROP TABLE t1;
 #
 # BUG#12616253 - WRONG RESULT WITH EXISTS(SUBQUERY) (MISSING ROWS)
@@ -6116,7 +6113,7 @@ set optimizer_switch=@tmp_optimizer_switch;
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
-2	SUBQUERY	t1	ref	a	a	5	const	1	Using index
+2	SUBQUERY	t1	ref	a	a	5	const	1	
 
 DROP TABLE t1;
 #
@@ -6557,6 +6554,41 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 COUNT(f1)	f4
 0	0
 drop table t1,t2;
+#
+# LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+# precomputed and thus not part of optimization
+#
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+field
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
+1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
+1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+MAX( alias2.a )
+Arden-Arcade
+drop table t1;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_sj_mat.result b/mysql-test/r/subselect_sj_mat.result
index dc1d9b407fd..d329c31fd16 100644
--- a/mysql-test/r/subselect_sj_mat.result
+++ b/mysql-test/r/subselect_sj_mat.result
@@ -1197,8 +1197,8 @@ 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 max(b1) from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 min(a1)
 NULL
@@ -1206,8 +1206,8 @@ set @@optimizer_switch=@optimizer_switch_local_default;
 set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
 NULL
@@ -1223,8 +1223,8 @@ NULL
 # but when we go around MWL#90 code, the problem still shows up:
 explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 min(a1)
 NULL
@@ -1971,7 +1971,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t2	index	c	c	5	NULL	8	Using index
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
-2	MATERIALIZED	s2	ref	d	d	4	const	1	Using where; Using index
+2	MATERIALIZED	s2	ref	d	d	4	const	2	Using where; Using index
 2	MATERIALIZED	s1	ALL	c	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	8	
 SELECT a, c FROM t1, t2
@@ -1991,8 +1991,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t2	index	c	c	5	NULL	8	Using index
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	
-2	MATERIALIZED	s2	ref	d	d	4	const	1	Using where; Using index
-2	MATERIALIZED	s1	hash_ALL	c	#hash#$hj	10	const,test.s2.d	8	Using where; Using join buffer (flat, BNLH join)
+2	MATERIALIZED	s2	ref	d	d	4	const	2	Using where; Using index
+2	MATERIALIZED	s1	hash_ALL	c	#hash#$hj	5	const	8	Using where; Using join buffer (flat, BNLH join)
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	8	
 SELECT a, c FROM t1, t2
 WHERE (a, c) IN (SELECT s1.b, s1.c FROM t2 AS s1, t2 AS s2
diff --git a/mysql-test/suite/sys_vars/r/all_vars.result b/mysql-test/suite/sys_vars/r/all_vars.result
index 1bd4e394f6a..692545ae0fb 100644
--- a/mysql-test/suite/sys_vars/r/all_vars.result
+++ b/mysql-test/suite/sys_vars/r/all_vars.result
@@ -10,5 +10,6 @@ there should be *no* long test name listed below:
 select distinct variable_name as `there should be *no* variables listed below:` from t2
 left join t1 on variable_name=test_name where test_name is null;
 there should be *no* variables listed below:
+expensive_subquery_limit
 drop table t1;
 drop table t2;
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index 6e98c064d94..d649c300ab5 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -304,6 +304,7 @@ SELECT (SELECT numeropost FROM t1 HAVING numreponse=a),numreponse FROM (SELECT *
 SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=a) FROM (SELECT * FROM t1) as a;
 SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT * FROM t1) as a;
 INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
+-- error ER_SUBQUERY_NO_1_ROW
 EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
 -- error ER_SUBQUERY_NO_1_ROW
 SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
@@ -5529,5 +5530,36 @@ SELECT COUNT(f1), f2 IN (SELECT f1 FROM t1 WHERE f2 > 0) AS f4 FROM t2, t1 WHERE
 drop table t1,t2;
 
 
+--echo #
+--echo # LP BUG#944706 Query with impossible or constant subquery in WHERE or HAVING is not
+--echo # precomputed and thus not part of optimization
+--echo #
+
+CREATE TABLE t1 ( a VARCHAR(16), KEY (a) );
+INSERT INTO t1 VALUES ('Abilene'),('Akron'),('Albany'),('Albuquerque'),('Alexandria'),('Allentown'),
+('Amarillo'),('Anaheim'),('Anchorage'),('Ann Arbor'),('Arden-Arcade');
+
+EXPLAIN
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+
+SELECT MAX( alias2.a ) AS field
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR alias1.a = 'y'
+HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a FROM t1 );
+
+EXPLAIN
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+
+SELECT MAX( alias2.a )
+FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
+WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
+
+drop table t1;
+
 --echo # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index 8915cdd6500..9ec282ba3db 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -977,6 +977,14 @@ SELECT * FROM t1 WHERE
         FROM t3 AS SQ1_t1 JOIN t3 AS SQ1_t3 ON SQ1_t3.f4
         GROUP BY SQ1_t1.f4));
 
+--error ER_SUBQUERY_NO_1_ROW
+SELECT * FROM t1 WHERE
+(SELECT f2 FROM t2
+ WHERE f4 <= ALL
+       (SELECT max(SQ1_t1.f4)
+        FROM t3 AS SQ1_t1 JOIN t3 AS SQ1_t3 ON SQ1_t3.f4
+        GROUP BY SQ1_t1.f4));
+
 drop table t1, t2, t3;
 
 --echo #
diff --git a/sql/item.h b/sql/item.h
index b3801e6c488..df220118745 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -1395,21 +1395,21 @@ public:
   {
     return cmp_context == IMPOSSIBLE_RESULT || item->cmp_context == cmp_context;
   }
-  /*
+  /**
     Test whether an expression is expensive to compute. Used during
     optimization to avoid computing expensive expressions during this
     phase. Also used to force temp tables when sorting on expensive
     functions.
-    TODO:
+    @todo
     Normally we should have a method:
       cost Item::execution_cost(),
     where 'cost' is either 'double' or some structure of various cost
     parameters.
 
-    NOTE
-      This function is now used to prevent evaluation of materialized IN
-      subquery predicates before it is allowed. grep for 
-      DontEvaluateMaterializedSubqueryTooEarly to see the uses.
+    @note
+      This function is now used to prevent evaluation of expensive subquery
+      predicates during the optimization phase. It also prevents evaluation
+      of predicates that are not computable at this moment.
   */
   virtual bool is_expensive()
   {
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index d3251bc1fb3..b45b138ced2 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -5539,7 +5539,15 @@ void Item_equal::add_const(Item *c, Item *f)
   else
   {
     Item_func_eq *func= new Item_func_eq(c, const_item);
-    func->set_cmp_func();
+    if (func->set_cmp_func())
+    {
+      /*
+        Setting a comparison function fails when trying to compare
+        incompatible charsets. Charset compatibility is checked earlier,
+        except for constant subqueries where we may do it here.
+      */
+      return;
+    }
     func->quick_fix_field();
     cond_false= !func->val_int();
   }
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index b9740c7af03..875fdc3b34f 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -370,9 +370,9 @@ public:
   Item_bool_func2(Item *a,Item *b)
     :Item_int_func(a,b), cmp(tmp_arg, tmp_arg+1), abort_on_null(FALSE) {}
   void fix_length_and_dec();
-  void set_cmp_func()
+  int set_cmp_func()
   {
-    cmp.set_cmp_func(this, tmp_arg, tmp_arg+1, TRUE);
+    return cmp.set_cmp_func(this, tmp_arg, tmp_arg+1, TRUE);
   }
   optimize_type select_optimize() const { return OPTIMIZE_OP; }
   virtual enum Functype rev_functype() const { return UNKNOWN_FUNC; }
diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index ad854b02765..b71408bd5f5 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -829,7 +829,7 @@ public:
   {
     DBUG_ASSERT(args[0]->fixed);
     conv_charset= cs;
-    if (cache_if_const && args[0]->const_item() && !args[0]->with_subselect)
+    if (cache_if_const && args[0]->const_item() && !args[0]->is_expensive())
     {
       uint errors= 0;
       String tmp, *str= args[0]->val_str(&tmp);
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 276f35fe301..1367037d17e 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -522,6 +522,48 @@ void Item_subselect::recalc_used_tables(st_select_lex *new_parent,
   */
 }
 
+
+/**
+  Determine if a subquery is expensive to execute during query optimization.
+
+  @details The cost of execution of a subquery is estimated based on an
+  estimate of the number of rows the subquery will access during execution.
+  This measure is used instead of JOIN::read_time, because it is considered
+  to be much more reliable than the cost estimate.
+
+  @return true if the subquery is expensive
+  @return false otherwise
+*/
+bool Item_subselect::is_expensive()
+{
+  double examined_rows= 0;
+
+  for (SELECT_LEX *sl= unit->first_select(); sl; sl= sl->next_select())
+  {
+    JOIN *cur_join= sl->join;
+    if (!cur_join)
+      continue;
+
+    /* If a subquery is not optimized we cannot estimate its cost. */
+    if (!cur_join->join_tab)
+      return true;
+
+    if (sl->first_inner_unit())
+    {
+      /*
+        Subqueries that contain subqueries are considered expensive.
+        @todo: accumulate the cost of subqueries.
+      */
+      return true;
+    }
+
+    examined_rows+= cur_join->get_examined_rows();
+  }
+
+  return (examined_rows > thd->variables.expensive_subquery_limit);
+}
+
+
 bool Item_subselect::walk(Item_processor processor, bool walk_subquery,
                           uchar *argument)
 {
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 1a4c8a25a01..746813407c2 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -209,7 +209,7 @@ public:
   */
   bool is_evaluated() const;
   bool is_uncacheable() const;
-  bool is_expensive() { return TRUE; }
+  bool is_expensive();
 
   /*
     Used by max/min subquery to initialize value presence registration
@@ -235,7 +235,7 @@ public:
     @retval TRUE  if the predicate is expensive
     @retval FALSE otherwise
   */
-  bool is_expensive_processor(uchar *arg) { return TRUE; }
+  bool is_expensive_processor(uchar *arg) { return is_expensive(); }
 
   /**
     Get the SELECT_LEX structure associated with this Item.
@@ -581,6 +581,10 @@ public:
   bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec();
   void fix_after_pullout(st_select_lex *new_parent, Item **ref);
+  bool const_item() const
+  {
+    return Item_subselect::const_item() && left_expr->const_item();
+  }
   void update_used_tables();
   bool setup_mat_engine();
   bool init_left_expr_cache();
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index 9bf1aaf4039..3e21187e6fa 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -4872,7 +4872,43 @@ static void remove_subq_pushed_predicates(JOIN *join, Item **where)
 
 bool JOIN::optimize_unflattened_subqueries()
 {
-  return select_lex->optimize_unflattened_subqueries();
+  return select_lex->optimize_unflattened_subqueries(false);
+}
+
+/**
+  Optimize all constant subqueries of a query that were not flattened into
+  a semijoin.
+
+  @details
+  Similar to other constant conditions, constant subqueries can be used in
+  various constant optimizations. Having optimized constant subqueries before
+  these constant optimizations, makes it possible to estimate if a subquery
+  is "cheap" enough to be executed during the optimization phase.
+
+  Constant subqueries can be optimized and evaluated independent of the outer
+  query, therefore if const_only = true, this method can be called early in
+  the optimization phase of the outer query.
+
+  @return Operation status
+  @retval FALSE     success.
+  @retval TRUE      error occurred.
+*/
+ 
+bool JOIN::optimize_constant_subqueries()
+{
+  ulonglong save_options= select_lex->options;
+  bool res;
+  /*
+    Constant subqueries may be executed during the optimization phase.
+    In EXPLAIN mode the optimizer doesn't initialize many of the data structures
+    needed for execution. In order to make it possible to execute subqueries
+    during optimization, constant subqueries must be optimized for execution,
+    not for EXPLAIN.
+  */
+  select_lex->options&= ~SELECT_DESCRIBE;
+  res= select_lex->optimize_unflattened_subqueries(true);
+  select_lex->options= save_options;
+  return res;
 }
 
 
@@ -5273,7 +5309,14 @@ bool JOIN::choose_subquery_plan(table_map join_tables)
       by the IN predicate.
     */
     outer_join= unit->outer_select() ? unit->outer_select()->join : NULL;
-    if (outer_join && outer_join->table_count > 0)
+    /*
+      Get the cost of the outer join if:
+      (1) It has at least one table, and
+      (2) It has been already optimized (if there is no join_tab, then the
+          outer join has not been optimized yet).
+    */
+    if (outer_join && outer_join->table_count > 0 && // (1)
+        outer_join->join_tab)                        // (2)
     {
       /*
         TODO:
diff --git a/sql/sql_class.h b/sql/sql_class.h
index c6c46975076..ee472e2e7e6 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -482,6 +482,7 @@ typedef struct system_variables
   ulonglong group_concat_max_len;
   ha_rows select_limit;
   ha_rows max_join_size;
+  ha_rows expensive_subquery_limit;
   ulong auto_increment_increment, auto_increment_offset;
   ulong lock_wait_timeout;
   ulong join_cache_level;
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index cc358eca440..5128b1284dd 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -120,7 +120,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   }
 
   /* Apply the IN=>EXISTS transformation to all subqueries and optimize them. */
-  if (select_lex->optimize_unflattened_subqueries())
+  if (select_lex->optimize_unflattened_subqueries(false))
     DBUG_RETURN(TRUE);
 
   const_cond= (!conds || conds->const_item());
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 6fd6e53424f..fb5307f9e3a 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -3405,7 +3405,23 @@ bool st_select_lex::add_index_hint (THD *thd, char *str, uint length)
 }
 
 
-bool st_select_lex::optimize_unflattened_subqueries()
+/**
+  Optimize all subqueries that have not been flattened into semi-joins.
+
+  @details
+  This functionality is a method of SELECT_LEX instead of JOIN because
+  SQL statements as DELETE/UPDATE do not have a corresponding JOIN object.
+
+  @see JOIN::optimize_unflattened_subqueries
+
+  @param const_only  Restrict subquery optimization to constant subqueries
+
+  @return Operation status
+  @retval FALSE     success.
+  @retval TRUE      error occurred.
+*/
+
+bool st_select_lex::optimize_unflattened_subqueries(bool const_only)
 {
   for (SELECT_LEX_UNIT *un= first_inner_unit(); un; un= un->next_unit())
   {
@@ -3415,11 +3431,17 @@ bool st_select_lex::optimize_unflattened_subqueries()
     {
       if (subquery_predicate->substype() == Item_subselect::IN_SUBS)
       {
-        Item_in_subselect *in_subs=(Item_in_subselect*)subquery_predicate;
+        Item_in_subselect *in_subs= (Item_in_subselect*) subquery_predicate;
         if (in_subs->is_jtbm_merged)
           continue;
       }
 
+      if (const_only && !subquery_predicate->const_item())
+      {
+        /* Skip non-constant subqueries if the caller asked so. */
+        continue;
+      }
+
       bool empty_union_result= true;
       /*
         If the subquery is a UNION, optimize all the subqueries in the UNION. If
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index f1ee6cf22ec..922386151f8 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -997,12 +997,7 @@ public:
 
   void clear_index_hints(void) { index_hints= NULL; }
   bool is_part_of_union() { return master_unit()->is_union(); }
-  /*
-    Optimize all subqueries that have not been flattened into semi-joins.
-    This functionality is a method of SELECT_LEX instead of JOIN because
-    some SQL statements as DELETE do not have a corresponding JOIN object.
-  */
-  bool optimize_unflattened_subqueries();
+  bool optimize_unflattened_subqueries(bool const_only);
   /* Set the EXPLAIN type for this subquery. */
   void set_explain_type();
   bool handle_derived(LEX *lex, uint phases);
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 916e521d3b9..933679a0d9c 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -986,7 +986,10 @@ JOIN::optimize()
   }
   
   eval_select_list_used_tables();
-  
+
+  if (optimize_constant_subqueries())
+    DBUG_RETURN(1);
+
   table_count= select_lex->leaf_tables.elements;
 
   if (setup_ftfuncs(select_lex)) /* should be after having->fix_fields */
@@ -1273,6 +1276,12 @@ JOIN::optimize()
   {
     conds= substitute_for_best_equal_field(NO_PARTICULAR_TAB, conds, 
                                            cond_equal, map2table);
+    if (thd->is_error())
+    {
+      error= 1;
+      DBUG_PRINT("error",("Error from substitute_for_best_equal"));
+      DBUG_RETURN(1);
+    }
     conds->update_used_tables();
     DBUG_EXECUTE("where",
                  print_where(conds,
@@ -1293,6 +1302,12 @@ JOIN::optimize()
                                                          *tab->on_expr_ref,
                                                          tab->cond_equal,
                                                          map2table);
+      if (thd->is_error())
+      {
+        error= 1;
+        DBUG_PRINT("error",("Error from substitute_for_best_equal"));
+        DBUG_RETURN(1);
+      }
       (*tab->on_expr_ref)->update_used_tables();
     }
   }
@@ -6591,6 +6606,33 @@ void JOIN::get_prefix_cost_and_fanout(uint n_tables,
 }
 
 
+/**
+  Estimate the number of rows that query execution will read.
+
+  @todo This is a very pessimistic upper bound. Use join selectivity
+  when available to produce a more realistic number.
+*/
+
+double JOIN::get_examined_rows()
+{
+  /* Each constant table examines one row, and the result is at most one row. */
+  ha_rows examined_rows= const_tables;
+  uint i= const_tables;
+  double prev_fanout= 1;
+
+  if (table_count == const_tables)
+    return examined_rows;
+
+  examined_rows+= join_tab[i++].get_examined_rows();
+  for (; i < table_count ; i++)
+  {
+    prev_fanout *= best_positions[i-1].records_read;
+    examined_rows+= join_tab[i].get_examined_rows() * prev_fanout;
+  }
+  return examined_rows;
+}
+
+
 /**
   Find a good, possibly optimal, query execution plan (QEP) by a possibly
   exhaustive search.
@@ -8011,36 +8053,15 @@ JOIN::make_simple_join(JOIN *parent, TABLE *temp_table)
   row_limit= unit->select_limit_cnt;
   do_send_rows= row_limit ? 1 : 0;
 
-  join_tab->use_join_cache= FALSE;
-  join_tab->cache=0;			        /* No caching */
+  bzero(join_tab, sizeof(JOIN_TAB));
   join_tab->table=temp_table;
-  join_tab->cache_select= 0;
-  join_tab->select=0;
-  join_tab->select_cond= 0;                     // Avoid valgrind warning
   join_tab->set_select_cond(NULL, __LINE__);
-  join_tab->quick=0;
   join_tab->type= JT_ALL;			/* Map through all records */
   join_tab->keys.init();
   join_tab->keys.set_all();                     /* test everything in quick */
-  join_tab->info=0;
-  join_tab->on_expr_ref=0;
-  join_tab->last_inner= 0;
-  join_tab->first_unmatched= 0;
   join_tab->ref.key = -1;
-  join_tab->not_used_in_distinct=0;
   join_tab->read_first_record= join_init_read_record;
-  join_tab->preread_init_done= FALSE;
   join_tab->join= this;
-  join_tab->ref.key_parts= 0;
-  join_tab->keep_current_rowid= FALSE;
-  join_tab->flush_weedout_table= join_tab->check_weed_out_table= NULL;
-  join_tab->do_firstmatch= NULL;
-  join_tab->loosescan_match_tab= NULL;
-  join_tab->emb_sj_nest= NULL;
-  join_tab->pre_idx_push_select_cond= NULL;
-  join_tab->bush_root_tab= NULL;
-  join_tab->bush_children= NULL;
-  join_tab->last_leaf_in_bush= FALSE;
   bzero((char*) &join_tab->read_record,sizeof(join_tab->read_record));
   temp_table->status=0;
   temp_table->null_row=0;
@@ -10225,6 +10246,51 @@ double JOIN_TAB::scan_time()
   return res;
 }
 
+
+/**
+  Estimate the number of rows that a an access method will read from a table.
+
+  @todo: why not use JOIN_TAB::found_records
+*/
+
+ha_rows JOIN_TAB::get_examined_rows()
+{
+  ha_rows examined_rows;
+
+  if (select && select->quick)
+    examined_rows= select->quick->records;
+  else if (type == JT_NEXT || type == JT_ALL ||
+           type == JT_HASH || type ==JT_HASH_NEXT)
+  {
+    if (limit)
+    {
+      /*
+        @todo This estimate is wrong, a LIMIT query may examine much more rows
+        than the LIMIT itself.
+      */
+      examined_rows= limit;
+    }
+    else
+    {
+      if (table->is_filled_at_execution())
+        examined_rows= records;
+      else
+      {
+        /*
+          handler->info(HA_STATUS_VARIABLE) has been called in
+          make_join_statistics()
+        */
+        examined_rows= table->file->stats.records;
+      }
+    }
+  }
+  else
+    examined_rows= (ha_rows) records_read; 
+
+  return examined_rows;
+}
+
+
 /**
   Initialize the join_tab before reading.
   Currently only derived table/view materialization is done here.
@@ -11204,9 +11270,9 @@ static bool check_simple_equality(Item *left_item, Item *right_item,
         if (!item)
         {
           Item_func_eq *eq_item;
-          if ((eq_item= new Item_func_eq(orig_left_item, orig_right_item)))
+          if (!(eq_item= new Item_func_eq(orig_left_item, orig_right_item)) ||
+              eq_item->set_cmp_func())
             return FALSE;
-          eq_item->set_cmp_func();
           eq_item->quick_fix_field();
           item= eq_item;
         }  
@@ -11299,9 +11365,9 @@ static bool check_row_equality(THD *thd, Item *left_row, Item_row *right_row,
     if (!is_converted)
     {
       Item_func_eq *eq_item;
-      if (!(eq_item= new Item_func_eq(left_item, right_item)))
+      if (!(eq_item= new Item_func_eq(left_item, right_item)) ||
+          eq_item->set_cmp_func())
         return FALSE;
-      eq_item->set_cmp_func();
       eq_item->quick_fix_field();
       eq_list->push_back(eq_item);
     }
@@ -11987,9 +12053,8 @@ Item *eliminate_item_equal(COND *cond, COND_EQUAL *upper_levels,
       
       eq_item= new Item_func_eq(field_item->real_item(), head_item);
 
-      if (!eq_item)
+      if (!eq_item || eq_item->set_cmp_func())
         return 0;
-      eq_item->set_cmp_func();
       eq_item->quick_fix_field();
     }
     current_sjm= field_sjm;
@@ -12076,7 +12141,7 @@ Item *eliminate_item_equal(COND *cond, COND_EQUAL *upper_levels,
        Item_equal::get_first() for details.
 
   @return
-    The transformed condition
+    The transformed condition, or NULL in case of error
 */
 
 static COND* substitute_for_best_equal_field(JOIN_TAB *context_tab,
@@ -18544,6 +18609,7 @@ check_reverse_order:
           tab->ref.key_parts= 0;
           if (select_limit < table->file->stats.records)
             tab->limit= select_limit;
+          table->disable_keyread();
         }
       }
       else if (tab->type != JT_ALL)
@@ -21269,10 +21335,17 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
       }
       else
       {
-        TABLE_LIST *real_table= table->pos_in_table_list; 
-	item_list.push_back(new Item_string(real_table->alias,
-					    strlen(real_table->alias),
-					    cs));
+        TABLE_LIST *real_table= table->pos_in_table_list;
+        /*
+          Internal temporary tables have no corresponding table reference
+          object. Such a table may appear in EXPLAIN when a subquery that needs
+          a temporary table has been executed, and JOIN::exec replaced the
+          original JOIN with a plan to access the data in the temp table
+          (made by JOIN::make_simple_join).
+        */
+        const char *tab_name= real_table ? real_table->alias :
+                                           "internal_tmp_table";
+	item_list.push_back(new Item_string(tab_name, strlen(tab_name), cs));
       }
       /* "partitions" column */
       if (join->thd->lex->describe & DESCRIBE_PARTITIONS)
@@ -21430,32 +21503,8 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
       }
       else
       {
-        ha_rows examined_rows;
-        if (tab->select && tab->select->quick)
-          examined_rows= tab->select->quick->records;
-        else if (tab->type == JT_NEXT || tab->type == JT_ALL || is_hj)
-        {
-          if (tab->limit)
-            examined_rows= tab->limit;
-          else
-          {
-            if (tab->table->is_filled_at_execution())
-            {
-              examined_rows= tab->records;
-            }
-            else
-            {
-              /*
-                handler->info(HA_STATUS_VARIABLE) has been called in
-                make_join_statistics()
-              */
-              examined_rows= tab->table->file->stats.records;
-            }
-          }
-        }
-        else
-          examined_rows=(ha_rows)tab->records_read; 
- 
+        ha_rows examined_rows= tab->get_examined_rows();
+
         item_list.push_back(new Item_int((longlong) (ulonglong) examined_rows, 
                                          MY_INT64_NUM_DECIMAL_DIGITS));
 
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 08ddc27e204..ee91928fa15 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -512,6 +512,7 @@ typedef struct st_join_table {
     return (is_hash_join_key_no(key) ? hj_key : table->key_info+key);
   }
   double scan_time();
+  ha_rows get_examined_rows();
   bool preread_init();
 
   bool is_sjm_nest() { return test(bush_children); }
@@ -1281,6 +1282,7 @@ public:
   bool alloc_func_list();
   bool flatten_subqueries();
   bool optimize_unflattened_subqueries();
+  bool optimize_constant_subqueries();
   bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
 			  bool before_group_by, bool recompute= FALSE);
 
@@ -1380,6 +1382,7 @@ public:
   void get_prefix_cost_and_fanout(uint n_tables, 
                                   double *read_time_arg,
                                   double *record_count_arg);
+  double get_examined_rows();
   /* defined in opt_subselect.cc */
   bool transform_max_min_subquery();
   /* True if this JOIN is a subquery under an IN predicate. */
diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 7d5fe875d64..f2b6c5c9f92 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -368,7 +368,7 @@ int mysql_update(THD *thd,
   }
 
   /* Apply the IN=>EXISTS transformation to all subqueries and optimize them. */
-  if (select_lex->optimize_unflattened_subqueries())
+  if (select_lex->optimize_unflattened_subqueries(false))
     DBUG_RETURN(TRUE);
 
   if (select_lex->inner_refs_list.elements &&
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index ca434821800..65b21273348 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -3780,4 +3780,9 @@ static Sys_var_ulong Sys_debug_binlog_fsync_sleep(
        CMD_LINE(REQUIRED_ARG),
        VALID_RANGE(0, UINT_MAX), DEFAULT(0), BLOCK_SIZE(1));
 #endif
-
+static Sys_var_harows Sys_expensive_subquery_limit(
+       "expensive_subquery_limit",
+       "The maximum number of rows a subquery may examine in order to be "
+       "executed during optimization and used for constant optimization",
+       SESSION_VAR(expensive_subquery_limit), CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(0, HA_POS_ERROR), DEFAULT(100), BLOCK_SIZE(1));
diff --git a/sql/table.cc b/sql/table.cc
index 40304dc6fdc..bc7ad0e5831 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -5985,7 +5985,13 @@ void TABLE::use_index(int key_to_save)
 
 bool TABLE::is_filled_at_execution()
 { 
-  return test(pos_in_table_list->jtbm_subselect || 
+  /*
+    pos_in_table_list == NULL for internal temporary tables because they
+    do not have a corresponding table reference. Such tables are filled
+    during execution.
+  */
+  return test(!pos_in_table_list ||
+              pos_in_table_list->jtbm_subselect || 
               pos_in_table_list->is_active_sjm());
 }
 

From e5bca74bfb47a1c45c995573fd58b1a751ccd884 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Fri, 18 May 2012 14:52:01 +0300
Subject: [PATCH 2/5] Fixed bug mdev-277 as part of the fix for lp:944706

The cause for this bug is that the method JOIN::get_examined_rows iterates over all
JOIN_TABs of the join assuming they are just a sequence. In the query above, the
innermost subquery is merged into its parent query. When we call
JOIN::get_examined_rows for the second-level subquery, the iteration that
assumes sequential order of join tabs goes outside the join_tab array and calls
the method JOIN_TAB::get_examined_rows on uninitialized memory.

The fix is to iterate over JOIN_TABs in a way that takes into account the nested
semi-join structure of JOIN_TABs. In particular iterate as select_describe.
---
 mysql-test/r/subselect.result             | 21 +++++++++++++++++++++
 mysql-test/r/subselect_no_mat.result      | 20 ++++++++++++++++++++
 mysql-test/r/subselect_no_opts.result     | 21 +++++++++++++++++++++
 mysql-test/r/subselect_no_scache.result   | 21 +++++++++++++++++++++
 mysql-test/r/subselect_no_semijoin.result | 21 +++++++++++++++++++++
 mysql-test/t/subselect.test               | 19 +++++++++++++++++++
 sql/sql_select.cc                         | 19 ++++++++++---------
 7 files changed, 133 insertions(+), 9 deletions(-)

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index a75d0f960af..05773560ba8 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -6594,5 +6594,26 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 MAX( alias2.a )
 Arden-Arcade
 drop table t1;
+#
+# MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+# with semijoin+materialization, IN and = subqueries
+#
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, 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	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+a1
+drop table t1, t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 507c8741d25..2465c1af367 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -6593,6 +6593,26 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 MAX( alias2.a )
 Arden-Arcade
 drop table t1;
+#
+# MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+# with semijoin+materialization, IN and = subqueries
+#
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, 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	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; Using join buffer (flat, BNL join)
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	End temporary; Using join buffer (flat, BNL join)
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+a1
+drop table t1, t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 9ca09ac061c..7dacffe0b74 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -6589,6 +6589,27 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 MAX( alias2.a )
 Arden-Arcade
 drop table t1;
+#
+# MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+# with semijoin+materialization, IN and = subqueries
+#
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, 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	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+a1
+drop table t1, t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index f7a8e8efd01..e3a938cdece 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -6600,6 +6600,27 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 MAX( alias2.a )
 Arden-Arcade
 drop table t1;
+#
+# MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+# with semijoin+materialization, IN and = subqueries
+#
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, 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	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+a1
+drop table t1, t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index f0186c682a4..6bb6b2861f9 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -6589,6 +6589,27 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 MAX( alias2.a )
 Arden-Arcade
 drop table t1;
+#
+# MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+# with semijoin+materialization, IN and = subqueries
+#
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, 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	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	<subquery3>	eq_ref	distinct_key	distinct_key	4	func	1	
+3	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+a1
+drop table t1, t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index d649c300ab5..f63ac838d2c 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -5561,5 +5561,24 @@ WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
 
 drop table t1;
 
+--echo #
+--echo # MDEV-277 CHEAP SQ: Server crashes in st_join_table::get_examined_rows
+--echo # with semijoin+materialization, IN and = subqueries
+--echo #
+
+CREATE TABLE t1 (a1 INT);
+INSERT INTO t1 VALUES (4),(6);
+CREATE TABLE t2 (b1 INT);
+INSERT INTO t2 VALUES (1),(7);
+
+EXPLAIN
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+
+SELECT * FROM t1
+WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
+
+drop table t1, t2;
+
 --echo # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 933679a0d9c..10c841639a9 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -270,6 +270,8 @@ Item_equal *find_item_equal(COND_EQUAL *cond_equal, Field *field,
                             bool *inherited_fl);
 JOIN_TAB *first_depth_first_tab(JOIN* join);
 JOIN_TAB *next_depth_first_tab(JOIN* join, JOIN_TAB* tab);
+JOIN_TAB *first_breadth_first_tab(JOIN *join);
+JOIN_TAB *next_breadth_first_tab(JOIN *join, JOIN_TAB *tab);
 
 /**
   This handles SELECT with and without UNION.
@@ -6615,19 +6617,18 @@ void JOIN::get_prefix_cost_and_fanout(uint n_tables,
 
 double JOIN::get_examined_rows()
 {
-  /* Each constant table examines one row, and the result is at most one row. */
-  ha_rows examined_rows= const_tables;
-  uint i= const_tables;
+  ha_rows examined_rows;
   double prev_fanout= 1;
+  JOIN_TAB *tab= first_breadth_first_tab(this);
+  JOIN_TAB *prev_tab= tab;
 
-  if (table_count == const_tables)
-    return examined_rows;
+  examined_rows= tab->get_examined_rows();
 
-  examined_rows+= join_tab[i++].get_examined_rows();
-  for (; i < table_count ; i++)
+  while ((tab= next_breadth_first_tab(this, tab)))
   {
-    prev_fanout *= best_positions[i-1].records_read;
-    examined_rows+= join_tab[i].get_examined_rows() * prev_fanout;
+    prev_fanout *= prev_tab->records_read;
+    examined_rows+= tab->get_examined_rows() * prev_fanout;
+    prev_tab= tab;
   }
   return examined_rows;
 }

From 4fa89b5fe05280fefa2b30df927d0db6c6888f98 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Thu, 24 May 2012 14:08:28 +0300
Subject: [PATCH 3/5] Test case for bug lp:1001117, MySQL BUG#12330344

Analysis:
The problem in the original MySQL bug is that the range optimizer
performs its analysis in a separate MEM_ROOT object that is freed
after the range optimzier is done. During range analysis get_mm_tree
calls Item_func_like::select_optimize, which in turn evaluates its
right argument. In the test case the right argument is a subquery.

In MySQL, subqueries are optimized lazyly, thus the call to val_str
triggers optimization for the subquery. All objects needed by the
subquery plan end up in the temporary MEM_ROOT used by the range
optimizer. When execution ends, the JOIN::cleanup process tries to
cleanup objects of the subquery plan, but all these objects are gone
with the temporary MEM_ROOT. The solution for MySQL is to switch the
mem_root.

In MariaDB with the patch for bug lp:944706, all constant subqueries
that may be used by the optimization process are preoptimized. Therefore
Item_func_like::select_optimize only triggers subquery execution, and
the above problem is not present.

The patch however adds a test whether the evaluated right argument of
the LIKE predicate is expensive. This is consistent with our approach
not to evaluate expensive expressions during optimization.
---
 mysql-test/r/partition.result | 12 ++++++++++++
 mysql-test/t/partition.test   | 13 +++++++++++++
 sql/item_cmpfunc.cc           |  2 +-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/partition.result b/mysql-test/r/partition.result
index 1bc1ea31671..431c5dda116 100644
--- a/mysql-test/r/partition.result
+++ b/mysql-test/r/partition.result
@@ -2461,3 +2461,15 @@ SELECT 1 FROM t1 JOIN t1 AS t2 USING (a);
 1
 1
 drop table t1;
+#
+# LP BUG#1001117 Crash on a simple select that uses a temptable view
+# MySQL Bug #12330344 Crash and/or valgrind errors in free_io_cache with join, view,
+# partitioned table
+#
+CREATE TABLE t1(a INT PRIMARY KEY) PARTITION BY LINEAR KEY (a);
+CREATE ALGORITHM=TEMPTABLE VIEW vtmp AS
+SELECT 1 FROM t1 AS t1_0 JOIN t1 ON t1_0.a LIKE (SELECT 1 FROM t1);
+SELECT * FROM vtmp;
+1
+DROP VIEW vtmp;
+DROP TABLE t1;
diff --git a/mysql-test/t/partition.test b/mysql-test/t/partition.test
index d6d49c59255..08c028c8224 100644
--- a/mysql-test/t/partition.test
+++ b/mysql-test/t/partition.test
@@ -2463,3 +2463,16 @@ INSERT INTO t1 VALUES (6,8,10);
 SELECT 1 FROM t1 JOIN t1 AS t2 USING (a);
 
 drop table t1;
+
+--echo #
+--echo # LP BUG#1001117 Crash on a simple select that uses a temptable view
+--echo # MySQL Bug #12330344 Crash and/or valgrind errors in free_io_cache with join, view,
+--echo # partitioned table
+--echo #
+
+CREATE TABLE t1(a INT PRIMARY KEY) PARTITION BY LINEAR KEY (a);
+CREATE ALGORITHM=TEMPTABLE VIEW vtmp AS
+SELECT 1 FROM t1 AS t1_0 JOIN t1 ON t1_0.a LIKE (SELECT 1 FROM t1);
+SELECT * FROM vtmp;
+DROP VIEW vtmp;
+DROP TABLE t1;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index b45b138ced2..560373b69e6 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -4736,7 +4736,7 @@ longlong Item_func_like::val_int()
 
 Item_func::optimize_type Item_func_like::select_optimize() const
 {
-  if (args[1]->const_item())
+  if (args[1]->const_item() && !args[1]->is_expensive())
   {
     String* res2= args[1]->val_str((String *)&cmp.value2);
     const char *ptr2;

From 941018f8d10240e9ec457ea6ab984844c343f6b6 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Wed, 30 May 2012 00:18:53 +0300
Subject: [PATCH 4/5] Patch for mdev-287: CHEAP SQ: A query with subquery in
 SELECT list, EXISTS, inner joins takes hundreds times longer

Analysis:

The fix for lp:944706 introduces early subquery optimization.
While a subquery is being optimized some of its predicates may be
removed. In the test case, the EXISTS subquery is constant, and is
evaluated to TRUE. As a result the whole OR is TRUE, and thus the
correlated condition "b = alias1.b" is optimized away. The subquery
becomes non-correlated.

The subquery cache is designed to work only for correlated subqueries.
If constant subquery optimization is disallowed, then the constant
subquery is not evaluated, the subquery remains correlated, and its
execution is cached. As a result execution is fast.

However, when the constant subquery was optimized away, it was neither
cached by the subquery cache, nor it was cached by the internal subquery
caching. The latter was due to the fact that the subquery still appeared
as correlated to the subselect_XYZ_engine::exec methods, and they
re-executed the subquery on each call to Item_subselect::exec.

Solution:

The solution is to update the correlated status of the subquery after it has
been optimized. This status consists of:
- st_select_lex::is_correlated
- Item_subselect::is_correlated
- SELECT_LEX::uncacheable
- SELECT_LEX_UNIT::uncacheable
The status is updated by st_select_lex::update_correlated_cache(), and its
caller st_select_lex::optimize_unflattened_subqueries. The solution relies
on the fact that the optimizer already called
st_select_lex::update_used_tables() for each subquery. This allows to
efficiently update the correlated status of each subquery without walking
the whole subquery tree.

Notice that his patch is an improvement over MySQL 5.6 and older, where
subqueries are not pre-optimized, and the above analysis is not possible.
---
 mysql-test/r/derived_opt.result               |  24 ++--
 mysql-test/r/explain.result                   |   4 +-
 mysql-test/r/index_merge_innodb.result        |   2 +-
 mysql-test/r/index_merge_myisam.result        |   2 +-
 mysql-test/r/join_outer.result                |   2 +-
 mysql-test/r/join_outer_jcl6.result           |   2 +-
 mysql-test/r/ps.result                        |  24 ++--
 mysql-test/r/subselect.result                 | 123 ++++++++++++++---
 mysql-test/r/subselect4.result                | 120 ++++++++---------
 .../r/subselect_extra_no_semijoin.result      |   4 +-
 mysql-test/r/subselect_mat.result             |  12 +-
 mysql-test/r/subselect_mat_cost.result        |   2 +-
 mysql-test/r/subselect_mat_cost_bugs.result   |   2 +-
 mysql-test/r/subselect_no_mat.result          | 127 +++++++++++++++---
 mysql-test/r/subselect_no_opts.result         | 125 ++++++++++++++---
 mysql-test/r/subselect_no_scache.result       | 121 ++++++++++++++---
 mysql-test/r/subselect_no_semijoin.result     | 115 +++++++++++++---
 mysql-test/r/subselect_partial_match.result   |   6 +-
 mysql-test/r/subselect_sj_mat.result          |   6 +-
 mysql-test/t/subselect.test                   |  44 ++++++
 sql/sql_lex.cc                                |  61 +++++++++
 sql/sql_lex.h                                 |   1 +
 22 files changed, 730 insertions(+), 199 deletions(-)

diff --git a/mysql-test/r/derived_opt.result b/mysql-test/r/derived_opt.result
index c5376bee756..11216a32e61 100644
--- a/mysql-test/r/derived_opt.result
+++ b/mysql-test/r/derived_opt.result
@@ -161,24 +161,24 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 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
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 execute stmt1 ;
 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
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 explain SELECT (SELECT SUM(c1 + c12 + 0.0) FROM t2 where (t1.c2 - 0e-3) = t2.c2 GROUP BY t1.c15 LIMIT 1) as scalar_s, exists (select 1.0e+0 from t2 where t2.c3 * 9.0000000000 = t1.c4) as exists_s, c5 * 4 in (select c6 + 0.3e+1 from t2) as in_s, (c7 - 4, c8 - 4) in (select c9 + 4.0, c10 + 40e-1 from t2) as in_row_s FROM t1, (select c25 x, c32 y from t2) tt WHERE x * 1 = c25;
 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
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 deallocate prepare stmt1;
 drop tables t1,t2;
 set @@optimizer_switch=@save_optimizer_switch;
diff --git a/mysql-test/r/explain.result b/mysql-test/r/explain.result
index 863526c637e..e081b56e6ce 100644
--- a/mysql-test/r/explain.result
+++ b/mysql-test/r/explain.result
@@ -225,10 +225,10 @@ INSERT INTO t2 VALUES (NULL), (0);
 EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = c) 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	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1276	Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
-Note	1003	select <expr_cache><NULL>((select 1 from `test`.`t2` where (`test`.`t2`.`d` = NULL))) AS `(SELECT 1 FROM t2 WHERE d = c)` from dual
+Note	1003	select (select 1 from `test`.`t2` where (`test`.`t2`.`d` = NULL)) AS `(SELECT 1 FROM t2 WHERE d = c)` from dual
 DROP TABLE t1, t2;
 #
 # Bug#30302: Tables that were optimized away are printed in the
diff --git a/mysql-test/r/index_merge_innodb.result b/mysql-test/r/index_merge_innodb.result
index 50b0147b6ad..ce65836d8bc 100644
--- a/mysql-test/r/index_merge_innodb.result
+++ b/mysql-test/r/index_merge_innodb.result
@@ -654,7 +654,7 @@ EXPLAIN SELECT t1.f1 FROM t1
 WHERE (SELECT COUNT(*) FROM t2 WHERE t2.f3 = 'h' AND t2.f2 = t1.f1) = 0 AND t1.f1 = 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	Using index
-2	DEPENDENT SUBQUERY	t2	index_merge	f2,f3	f3,f2	2,5	NULL	1	Using intersect(f3,f2); Using where; Using index
+2	SUBQUERY	t2	index_merge	f2,f3	f3,f2	2,5	NULL	1	Using intersect(f3,f2); Using where; Using index
 DROP TABLE t1,t2;
 # 
 # BUG#56862/640419: Wrong result with sort_union index merge when one
diff --git a/mysql-test/r/index_merge_myisam.result b/mysql-test/r/index_merge_myisam.result
index b560c1e5176..bf151a872cf 100644
--- a/mysql-test/r/index_merge_myisam.result
+++ b/mysql-test/r/index_merge_myisam.result
@@ -1487,7 +1487,7 @@ EXPLAIN SELECT t1.f1 FROM t1
 WHERE (SELECT COUNT(*) FROM t2 WHERE t2.f3 = 'h' AND t2.f2 = t1.f1) = 0 AND t1.f1 = 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	ref	f2,f3	f2	5	const	1	Using where
+2	SUBQUERY	t2	ref	f2,f3	f2	5	const	1	Using where
 DROP TABLE t1,t2;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
diff --git a/mysql-test/r/join_outer.result b/mysql-test/r/join_outer.result
index 49a6a0d76d3..074b8bcadaa 100644
--- a/mysql-test/r/join_outer.result
+++ b/mysql-test/r/join_outer.result
@@ -1872,7 +1872,7 @@ SELECT t2.a FROM t1 LEFT JOIN t2 ON (6) IN (SELECT a FROM t3);
 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	system	NULL	NULL	NULL	NULL	1	100.00	
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select NULL AS `a` from `test`.`t2` where 1
 DROP TABLE t1,t2,t3;
diff --git a/mysql-test/r/join_outer_jcl6.result b/mysql-test/r/join_outer_jcl6.result
index d1333136f1c..f40515bc9a0 100644
--- a/mysql-test/r/join_outer_jcl6.result
+++ b/mysql-test/r/join_outer_jcl6.result
@@ -1883,7 +1883,7 @@ SELECT t2.a FROM t1 LEFT JOIN t2 ON (6) IN (SELECT a FROM t3);
 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	system	NULL	NULL	NULL	NULL	1	100.00	
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select NULL AS `a` from `test`.`t2` where 1
 DROP TABLE t1,t2,t3;
diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result
index ce0926c6bc1..06443dc55ae 100644
--- a/mysql-test/r/ps.result
+++ b/mysql-test/r/ps.result
@@ -160,26 +160,26 @@ execute stmt1 ;
 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
 6	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 execute stmt1 ;
 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
 6	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 explain SELECT (SELECT SUM(c1 + c12 + 0.0) FROM t2 where (t1.c2 - 0e-3) = t2.c2 GROUP BY t1.c15 LIMIT 1) as scalar_s, exists (select 1.0e+0 from t2 where t2.c3 * 9.0000000000 = t1.c4) as exists_s, c5 * 4 in (select c6 + 0.3e+1 from t2) as in_s, (c7 - 4, c8 - 4) in (select c9 + 4.0, c10 + 40e-1 from t2) as in_row_s FROM t1, (select c25 x, c32 y from t2) tt WHERE x * 1 = c25;
 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
 6	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
-5	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-4	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+4	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 deallocate prepare stmt1;
 set optimizer_switch=@tmp_optimizer_switch;
 drop tables t1,t2;
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 05773560ba8..c90596315e1 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -51,12 +51,12 @@ ERROR 42S22: Reference 'a' not supported (forward reference in item list)
 EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
-Note	1003	select 1 AS `1` from dual having (<expr_cache><1>((select 1)) = 1)
+Note	1003	select 1 AS `1` from dual having ((select 1) = 1)
 SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
 1
 1
@@ -904,7 +904,7 @@ a	t1.a in (select t2.a from t2)
 explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
+2	SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having <is_not_null_test>(`test`.`t2`.`a`))))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
 CREATE TABLE t3 (a int(11) default '0');
@@ -1317,7 +1317,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from dual where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
@@ -1327,7 +1327,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
@@ -1605,25 +1605,25 @@ a3	1
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where (`test`.`t2`.`s1` < 'a2') having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
 drop table t1,t2;
@@ -3097,7 +3097,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@@ -3109,7 +3109,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@@ -3160,7 +3160,7 @@ INSERT INTO t2 VALUES (1),(2),(3);
 EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
+2	SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
 SELECT a, a IN (SELECT a FROM t1) FROM t2;
 a	a IN (SELECT a FROM t1)
 1	1
@@ -3696,7 +3696,7 @@ ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
+2	SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1
 WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
@@ -4577,7 +4577,7 @@ FROM t1
 WHERE a = 230;
 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
 FROM t1 
 WHERE a = 230;
@@ -5713,7 +5713,7 @@ 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 where
+2	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;
@@ -6530,7 +6530,7 @@ EXPLAIN
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	NULL
@@ -6538,7 +6538,7 @@ EXPLAIN
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	0
@@ -6573,7 +6573,7 @@ WHERE alias1.a = alias2.a OR alias1.a = 'y'
 HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a ) AS field
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR alias1.a = 'y'
@@ -6587,7 +6587,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
 1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
 1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a )
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
@@ -6615,5 +6615,90 @@ SELECT * FROM t1
 WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 a1
 drop table t1, t2;
+#
+# MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+# inner joins takes hundreds times longer
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+set @@expensive_subquery_limit= 0;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	6
+Subquery_cache_miss	2
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	8
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	22
+set @@expensive_subquery_limit= default;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	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)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	16
+drop table t1, t2, t3;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result
index c17ffe75282..e9284e427ef 100644
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -226,10 +226,10 @@ NULL
 EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = c) AS RESULT 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	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1276	Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
-Note	1003	select <expr_cache><>((select 1 from `test`.`t2` where 0)) AS `RESULT` from dual
+Note	1003	select (select 1 from `test`.`t2` where 0) AS `RESULT` from dual
 first equivalent variant
 SELECT (SELECT 1 FROM t2 WHERE d = IFNULL(c,NULL)) AS RESULT FROM t1 GROUP BY c ;
 RESULT
@@ -237,10 +237,10 @@ NULL
 EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = IFNULL(c,NULL)) AS RESULT FROM t1 GROUP BY c;
 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	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1276	Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
-Note	1003	select <expr_cache><>((select 1 from `test`.`t2` where 0)) AS `RESULT` from dual group by NULL
+Note	1003	select (select 1 from `test`.`t2` where 0) AS `RESULT` from dual group by NULL
 second equivalent variant
 SELECT (SELECT 1 FROM t2 WHERE d = c) AS RESULT FROM t1 GROUP BY c ;
 RESULT
@@ -248,10 +248,10 @@ NULL
 EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = c) AS RESULT FROM t1 GROUP BY c ;
 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	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1276	Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
-Note	1003	select <expr_cache><>((select 1 from `test`.`t2` where 0)) AS `RESULT` from dual group by NULL
+Note	1003	select (select 1 from `test`.`t2` where 0) AS `RESULT` from dual group by NULL
 DROP TABLE t1,t2;
 #
 # BUG#45928 "Differing query results depending on MRR and
@@ -649,7 +649,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -671,7 +671,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -679,7 +679,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) > 7) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) > 7) as not_in;
 not_in
 1
@@ -687,7 +687,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) is null) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) is null) as not_in;
 not_in
 NULL
@@ -695,7 +695,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -703,7 +703,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2) as not_in;
 not_in
 NULL
@@ -719,28 +719,28 @@ EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4) 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	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4) FROM t2);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3+f4, min(f4) 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	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3+f4, min(f4) FROM t2);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4)+max(f4) 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	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4)+max(f4) FROM t2);
 f1	f2
 EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -748,21 +748,21 @@ EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, count(f4) 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	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, count(f4) FROM t2);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, f3 + count(f4) 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	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, f3 + count(f4) FROM t2);
 f1	f2
 EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -770,7 +770,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) > 7) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) > 7) as not_in;
 not_in
 1
@@ -778,7 +778,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) is null) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 HAVING max(f4) is null) as not_in;
 not_in
 NULL
@@ -786,7 +786,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2) as not_in;
 not_in
 NULL
@@ -794,7 +794,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	0	const row not found
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2) as not_in;
 not_in
 NULL
@@ -835,7 +835,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -857,7 +857,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -865,7 +865,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) > 7) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) > 7) as not_in;
 not_in
 1
@@ -873,7 +873,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) is null) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) is null) as not_in;
 not_in
 NULL
@@ -881,7 +881,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -889,7 +889,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -905,28 +905,28 @@ EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3+f4, min(f4) FROM t2 WHERE f3 > 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3+f4, min(f4) FROM t2 WHERE f3 > 10);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4)+max(f4) FROM t2 WHERE f3 > 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, min(f4)+max(f4) FROM t2 WHERE f3 > 10);
 f1	f2
 EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, min(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -934,21 +934,21 @@ EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10);
 f1	f2
 EXPLAIN
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, f3 + count(f4) FROM t2 WHERE f3 > 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT * FROM t1 WHERE (2, 0) NOT IN (SELECT f3, f3 + count(f4) FROM t2 WHERE f3 > 10);
 f1	f2
 EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -956,7 +956,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) > 7) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) > 7) as not_in;
 not_in
 1
@@ -964,7 +964,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) is null) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT f3, count(f4) FROM t2 WHERE f3 > 10 HAVING max(f4) is null) as not_in;
 not_in
 NULL
@@ -972,7 +972,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4) FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -980,7 +980,7 @@ EXPLAIN
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2 WHERE f3 > 10) as not_in;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
+2	SUBQUERY	t2	range	PRIMARY	PRIMARY	4	NULL	1	Using index condition; Rowid-ordered scan
 SELECT (2, 0) NOT IN (SELECT max(f3+f3), count(f4)+f3 FROM t2 WHERE f3 > 10) as not_in;
 not_in
 NULL
@@ -1240,7 +1240,7 @@ EXPLAIN
 SELECT i FROM t1 WHERE (1) NOT IN (SELECT i FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	index_subquery	k	k	5	const	2	Using index
+2	SUBQUERY	t2	index_subquery	k	k	5	const	2	Using index
 DROP TABLE t2;
 DROP TABLE t1;
 #
@@ -1258,8 +1258,8 @@ WHERE ('v') IN (SELECT f4 FROM t2)
 GROUP BY f9;
 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
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
 (SELECT COUNT(f3) FROM t1 WHERE t2.f1) AS f9
 FROM t2 JOIN t1 ON t1.f3
@@ -1274,8 +1274,8 @@ WHERE ('v') IN (SELECT f4 FROM t2)
 ORDER BY f9;
 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
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
 (SELECT COUNT(f3) FROM t1 WHERE t2.f1) AS f9
 FROM t2 JOIN t1 ON t1.f3
@@ -1291,8 +1291,8 @@ WHERE ('v') IN (SELECT f4 FROM t2)
 GROUP BY f9;
 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
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
 (SELECT t2.f1 FROM t1 limit 1) AS f9
 FROM t2 JOIN t1
@@ -1307,8 +1307,8 @@ WHERE ('v') IN (SELECT f4 FROM t2)
 ORDER BY f9;
 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
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(t2.f3),
 (SELECT t2.f1 FROM t1 limit 1) AS f9
 FROM t2 JOIN t1
@@ -1390,7 +1390,7 @@ EXPLAIN
 SELECT 'bug' FROM DUAL WHERE ( 5 ) IN ( SELECT * FROM v1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1400,7 +1400,7 @@ EXPLAIN
 SELECT ( 5 ) IN ( SELECT * FROM v1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1411,7 +1411,7 @@ EXPLAIN
 SELECT 'bug' FROM DUAL WHERE ( 5 ) IN (SELECT * FROM v2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	t1	system	NULL	NULL	NULL	NULL	1	
 4	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1431,7 +1431,7 @@ EXPLAIN
 SELECT ( 5 ) IN ( SELECT * FROM v2 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	t1	system	NULL	NULL	NULL	NULL	1	
 4	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1443,7 +1443,7 @@ EXPLAIN
 SELECT 'bug' FROM DUAL WHERE ( 5 ) IN ( SELECT * FROM v1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1453,7 +1453,7 @@ EXPLAIN
 SELECT ( 5 ) IN ( SELECT * FROM v1 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1464,7 +1464,7 @@ EXPLAIN
 SELECT 'bug' FROM DUAL WHERE ( 5 ) IN (SELECT * FROM v2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	t1	system	NULL	NULL	NULL	NULL	1	
 4	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1474,7 +1474,7 @@ EXPLAIN
 SELECT 'bug' FROM t3 WHERE ( 5 ) IN (SELECT * FROM v2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	t1	system	NULL	NULL	NULL	NULL	1	
 4	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1484,7 +1484,7 @@ EXPLAIN
 SELECT ( 5 ) IN ( SELECT * FROM v2 );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using where
 3	DERIVED	t1	system	NULL	NULL	NULL	NULL	1	
 4	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -1635,8 +1635,8 @@ EXPLAIN
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
 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	DEPENDENT SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
-2	DEPENDENT SUBQUERY	t2	ref_or_null	f10	f10	10	const,const	2	Using where; Using index
+2	SUBQUERY	t3	system	NULL	NULL	NULL	NULL	1	
+2	SUBQUERY	t2	ref_or_null	f10	f10	10	const,const	2	Using where; Using index
 SELECT * FROM t1 WHERE ( 6 ) NOT IN ( SELECT t2.f3 FROM t2 JOIN t3 ON t3.f10 = t2.f10);
 f4
 drop table t1,t2,t3;
diff --git a/mysql-test/r/subselect_extra_no_semijoin.result b/mysql-test/r/subselect_extra_no_semijoin.result
index 773ee9898a4..ba001c71e3f 100644
--- a/mysql-test/r/subselect_extra_no_semijoin.result
+++ b/mysql-test/r/subselect_extra_no_semijoin.result
@@ -46,7 +46,7 @@ select * from t1
 where id in (select id from t1 as x1 where (t1.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1276	Field or reference 'test.t1.cur_date' of SELECT #2 was resolved in SELECT #1
 Note	1003	select 1 AS `id`,'2007-04-25 18:30:22' AS `cur_date` from dual where <expr_cache><1>(<in_optimizer>(1,<exists>(select `test`.`x1`.`id` from `test`.`t1` `x1` where 0)))
@@ -58,7 +58,7 @@ select * from t2
 where id in (select id from t2 as x1 where (t2.cur_date is null));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
 Warnings:
 Note	1276	Field or reference 'test.t2.cur_date' of SELECT #2 was resolved in SELECT #1
 Note	1003	select 1 AS `id`,'2007-04-25' AS `cur_date` from dual where <expr_cache><1>(<in_optimizer>(1,<exists>(select `test`.`x1`.`id` from `test`.`t2` `x1` where 0)))
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 323da97cc89..7485a9fa436 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -1163,7 +1163,7 @@ set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 min(a1)
 NULL
@@ -1182,7 +1182,7 @@ set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
 NULL
@@ -1190,7 +1190,7 @@ NULL
 explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 min(a1)
 NULL
@@ -2162,7 +2162,7 @@ EXPLAIN
 SELECT (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
 (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1)
@@ -2179,7 +2179,7 @@ EXPLAIN
 SELECT (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-3	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
 (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1)
@@ -2234,7 +2234,7 @@ EXPLAIN EXTENDED
 SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where 0
 DROP TABLE t1,t2;
diff --git a/mysql-test/r/subselect_mat_cost.result b/mysql-test/r/subselect_mat_cost.result
index 893209a07fc..081196a227b 100644
--- a/mysql-test/r/subselect_mat_cost.result
+++ b/mysql-test/r/subselect_mat_cost.result
@@ -496,7 +496,7 @@ 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	DEPENDENT SUBQUERY	Country	index_subquery	CountryCapital	CountryCapital	5	func	2	Using index; Using where
+2	SUBQUERY	Country	index_subquery	CountryCapital	CountryCapital	5	func	2	Using index; 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;
diff --git a/mysql-test/r/subselect_mat_cost_bugs.result b/mysql-test/r/subselect_mat_cost_bugs.result
index e656bf8e22f..635e868dd31 100644
--- a/mysql-test/r/subselect_mat_cost_bugs.result
+++ b/mysql-test/r/subselect_mat_cost_bugs.result
@@ -124,7 +124,7 @@ FROM t3 RIGHT JOIN t1 ON t1.pk = t3.f1
 WHERE t3.f3 OR ( 3 ) IN ( SELECT f2 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	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 SELECT t1.*
 FROM t3 RIGHT JOIN t1 ON t1.pk = t3.f1
 WHERE t3.f3 OR ( 3 ) IN ( SELECT f2 FROM t2 );
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 2465c1af367..0722ca7ba88 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -58,12 +58,12 @@ ERROR 42S22: Reference 'a' not supported (forward reference in item list)
 EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
-Note	1003	select 1 AS `1` from dual having (<expr_cache><1>((select 1)) = 1)
+Note	1003	select 1 AS `1` from dual having ((select 1) = 1)
 SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
 1
 1
@@ -911,7 +911,7 @@ a	t1.a in (select t2.a from t2)
 explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
+2	SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having <is_not_null_test>(`test`.`t2`.`a`))))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
 CREATE TABLE t3 (a int(11) default '0');
@@ -1324,7 +1324,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from dual where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
@@ -1334,7 +1334,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
@@ -1612,25 +1612,25 @@ a3	1
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where (`test`.`t2`.`s1` < 'a2') having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
 drop table t1,t2;
@@ -3103,7 +3103,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@@ -3115,7 +3115,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@@ -3166,7 +3166,7 @@ INSERT INTO t2 VALUES (1),(2),(3);
 EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
+2	SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
 SELECT a, a IN (SELECT a FROM t1) FROM t2;
 a	a IN (SELECT a FROM t1)
 1	1
@@ -3700,7 +3700,7 @@ ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
+2	SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1
 WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
@@ -4526,13 +4526,13 @@ SET join_cache_level=0;
 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
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
 Note	1003	select 1 AS `1` from `test`.`t1` where 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+2	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 0
 SET join_cache_level=@save_join_cache_level;
@@ -4579,7 +4579,7 @@ FROM t1
 WHERE a = 230;
 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
 FROM t1 
 WHERE a = 230;
@@ -5714,7 +5714,7 @@ 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 where
+2	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;
@@ -6529,7 +6529,7 @@ EXPLAIN
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	NULL
@@ -6537,7 +6537,7 @@ EXPLAIN
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	0
@@ -6572,7 +6572,7 @@ WHERE alias1.a = alias2.a OR alias1.a = 'y'
 HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a ) AS field
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR alias1.a = 'y'
@@ -6586,7 +6586,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
 1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
 1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a )
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
@@ -6613,6 +6613,91 @@ SELECT * FROM t1
 WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 a1
 drop table t1, t2;
+#
+# MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+# inner joins takes hundreds times longer
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+set @@expensive_subquery_limit= 0;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	6
+Subquery_cache_miss	2
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	8
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	22
+set @@expensive_subquery_limit= default;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	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)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	16
+drop table t1, t2, t3;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 7dacffe0b74..27cf1f70864 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -54,7 +54,7 @@ ERROR 42S22: Reference 'a' not supported (forward reference in item list)
 EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
@@ -907,7 +907,7 @@ a	t1.a in (select t2.a from t2)
 explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
+2	SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
 CREATE TABLE t3 (a int(11) default '0');
@@ -1320,7 +1320,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from dual where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
@@ -1330,7 +1330,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
@@ -1608,25 +1608,25 @@ a3	1
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where (`test`.`t2`.`s1` < 'a2') having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
 drop table t1,t2;
@@ -3099,7 +3099,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@@ -3111,7 +3111,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@@ -3162,7 +3162,7 @@ INSERT INTO t2 VALUES (1),(2),(3);
 EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
+2	SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
 SELECT a, a IN (SELECT a FROM t1) FROM t2;
 a	a IN (SELECT a FROM t1)
 1	1
@@ -3696,7 +3696,7 @@ ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
+2	SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1
 WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
@@ -4522,13 +4522,13 @@ SET join_cache_level=0;
 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
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
 Note	1003	select 1 AS `1` from `test`.`t1` where 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+2	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 0
 SET join_cache_level=@save_join_cache_level;
@@ -4575,7 +4575,7 @@ FROM t1
 WHERE a = 230;
 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
 FROM t1 
 WHERE a = 230;
@@ -5710,7 +5710,7 @@ 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 where
+2	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;
@@ -6525,7 +6525,7 @@ EXPLAIN
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	NULL
@@ -6533,7 +6533,7 @@ EXPLAIN
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	0
@@ -6568,7 +6568,7 @@ WHERE alias1.a = alias2.a OR alias1.a = 'y'
 HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a ) AS field
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR alias1.a = 'y'
@@ -6582,7 +6582,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
 1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
 1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a )
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
@@ -6610,6 +6610,91 @@ SELECT * FROM t1
 WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 a1
 drop table t1, t2;
+#
+# MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+# inner joins takes hundreds times longer
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+set @@expensive_subquery_limit= 0;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	6
+Subquery_cache_miss	2
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	8
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	22
+set @@expensive_subquery_limit= default;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	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)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	16
+drop table t1, t2, t3;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index e3a938cdece..9994ede79de 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -57,7 +57,7 @@ ERROR 42S22: Reference 'a' not supported (forward reference in item list)
 EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
@@ -910,7 +910,7 @@ a	t1.a in (select t2.a from t2)
 explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
+2	SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
 CREATE TABLE t3 (a int(11) default '0');
@@ -1323,7 +1323,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from dual where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
@@ -1333,7 +1333,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
@@ -1611,25 +1611,25 @@ a3	1
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
 explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
-2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
+2	SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
 Warnings:
 Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where (`test`.`t2`.`s1` < 'a2') having trigcond(<is_not_null_test>(`test`.`t2`.`s1`))))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
 drop table t1,t2;
@@ -3103,7 +3103,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@@ -3115,7 +3115,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@@ -3166,7 +3166,7 @@ INSERT INTO t2 VALUES (1),(2),(3);
 EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
+2	SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
 SELECT a, a IN (SELECT a FROM t1) FROM t2;
 a	a IN (SELECT a FROM t1)
 1	1
@@ -3702,7 +3702,7 @@ ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
+2	SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1
 WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
@@ -4583,7 +4583,7 @@ FROM t1
 WHERE a = 230;
 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
 FROM t1 
 WHERE a = 230;
@@ -5719,7 +5719,7 @@ 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 where
+2	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;
@@ -6536,7 +6536,7 @@ EXPLAIN
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	NULL
@@ -6544,7 +6544,7 @@ EXPLAIN
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	0
@@ -6579,7 +6579,7 @@ WHERE alias1.a = alias2.a OR alias1.a = 'y'
 HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a ) AS field
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR alias1.a = 'y'
@@ -6593,7 +6593,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
 1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
 1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a )
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
@@ -6621,6 +6621,91 @@ SELECT * FROM t1
 WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 a1
 drop table t1, t2;
+#
+# MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+# inner joins takes hundreds times longer
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+set @@expensive_subquery_limit= 0;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	58
+set @@expensive_subquery_limit= default;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	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)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	16
+drop table t1, t2, t3;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index 6bb6b2861f9..1973262cdaf 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -54,12 +54,12 @@ ERROR 42S22: Reference 'a' not supported (forward reference in item list)
 EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
-3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
 Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
-Note	1003	select 1 AS `1` from dual having (<expr_cache><1>((select 1)) = 1)
+Note	1003	select 1 AS `1` from dual having ((select 1) = 1)
 SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
 1
 1
@@ -1320,7 +1320,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from dual where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 INSERT INTO t1 (pseudo) VALUES ('test1');
@@ -1330,7 +1330,7 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
 EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
 drop table t1;
@@ -3099,7 +3099,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@@ -3111,7 +3111,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
 1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
 SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
 ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
             ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@@ -3696,7 +3696,7 @@ ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
+2	SUBQUERY	t1	range	PRIMARY	PRIMARY	16	NULL	5	Using where; Using index
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1
 WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
@@ -4522,13 +4522,13 @@ SET join_cache_level=0;
 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
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary
 Warnings:
 Note	1003	select 1 AS `1` from `test`.`t1` where 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using temporary
+2	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 0
 SET join_cache_level=@save_join_cache_level;
@@ -4575,7 +4575,7 @@ FROM t1
 WHERE a = 230;
 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	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
 FROM t1 
 WHERE a = 230;
@@ -5710,7 +5710,7 @@ 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 where
+2	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;
@@ -6525,7 +6525,7 @@ EXPLAIN
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), (SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	NULL
@@ -6533,7 +6533,7 @@ EXPLAIN
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 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	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(f1), exists(SELECT f1 FROM t1 WHERE f2 > 0 limit 1) AS f4 FROM t2, t1 WHERE 'v'= f3;
 COUNT(f1)	f4
 0	0
@@ -6568,7 +6568,7 @@ WHERE alias1.a = alias2.a OR alias1.a = 'y'
 HAVING field>'B' AND ( 'Moscow' ) IN ( SELECT a 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 HAVING
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a ) AS field
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR alias1.a = 'y'
@@ -6582,7 +6582,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	alias1	index	a	a	19	NULL	11	Using where; Using index
 1	PRIMARY	alias2	ref	a	a	19	test.alias1.a	2	Using index
 1	PRIMARY	alias3	index	NULL	a	19	NULL	11	Using index; Using join buffer (flat, BNL join)
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
+2	SUBQUERY	t1	index_subquery	a	a	19	const	1	Using index; Using where
 SELECT MAX( alias2.a )
 FROM t1 AS alias1, t1 AS alias2, t1 AS alias3
 WHERE alias1.a = alias2.a OR ('Moscow') IN ( SELECT a FROM t1 );
@@ -6610,6 +6610,91 @@ SELECT * FROM t1
 WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 a1
 drop table t1, t2;
+#
+# MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+# inner joins takes hundreds times longer
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+set @@expensive_subquery_limit= 0;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	6
+Subquery_cache_miss	2
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	8
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	22
+set @@expensive_subquery_limit= default;
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	alias1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	PRIMARY	alias3	ALL	NULL	NULL	NULL	NULL	2	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)
+3	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	2	
+flush status;
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+(SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+NULL
+show status like "subquery_cache%";
+Variable_name	Value
+Subquery_cache_hit	0
+Subquery_cache_miss	0
+show status like '%Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_last	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_deleted	0
+Handler_read_rnd_next	16
+drop table t1, t2, t3;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_partial_match.result b/mysql-test/r/subselect_partial_match.result
index 4e37b831326..9dc2b44fd30 100644
--- a/mysql-test/r/subselect_partial_match.result
+++ b/mysql-test/r/subselect_partial_match.result
@@ -879,7 +879,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2);
 c
 0
@@ -888,7 +888,7 @@ EXPLAIN
 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2);
 c
 0
@@ -913,7 +913,7 @@ set @@optimizer_switch='in_to_exists=on,materialization=off';
 EXPLAIN SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 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	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 FROM t1 );
 f3
 5
diff --git a/mysql-test/r/subselect_sj_mat.result b/mysql-test/r/subselect_sj_mat.result
index d329c31fd16..01a4c7d67c9 100644
--- a/mysql-test/r/subselect_sj_mat.result
+++ b/mysql-test/r/subselect_sj_mat.result
@@ -1198,7 +1198,7 @@ set @@optimizer_switch='materialization=off,in_to_exists=on';
 explain select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select max(b1) from t2 group by b1);
 min(a1)
 NULL
@@ -1207,7 +1207,7 @@ set @@optimizer_switch='semijoin=off';
 explain select min(a1) from t1 where 7 in (select b1 from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2);
 min(a1)
 NULL
@@ -1224,7 +1224,7 @@ NULL
 explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
-2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
 min(a1)
 NULL
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index f63ac838d2c..1cbb15b0b95 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -5580,5 +5580,49 @@ WHERE a1 = (SELECT COUNT(*) FROM t1 WHERE a1 IN (SELECT a1 FROM t1, t2));
 
 drop table t1, t2;
 
+--echo #
+--echo # MDEV-287 CHEAP SQ: A query with subquery in SELECT list, EXISTS,
+--echo # inner joins takes hundreds times longer
+--echo #
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(7);
+
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (4),(5);
+
+CREATE TABLE t3 (c INT);
+INSERT INTO t3 VALUES (8),(3);
+
+set @@expensive_subquery_limit= 0;
+
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+
+flush status;
+
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+
+show status like "subquery_cache%";
+show status like '%Handler_read%';
+
+set @@expensive_subquery_limit= default;
+
+EXPLAIN
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+
+flush status;
+
+SELECT (SELECT MIN(b) FROM t1, t2 WHERE b = a AND (b = alias1.b OR EXISTS (SELECT * FROM t3)))
+FROM t2 alias1, t1 alias2, t1 alias3;
+
+show status like "subquery_cache%";
+show status like '%Handler_read%';
+
+drop table t1, t2, t3;
+
 --echo # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index fb5307f9e3a..0392e807519 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -3443,6 +3443,7 @@ bool st_select_lex::optimize_unflattened_subqueries(bool const_only)
       }
 
       bool empty_union_result= true;
+      bool is_correlated_unit= false;
       /*
         If the subquery is a UNION, optimize all the subqueries in the UNION. If
         there is no UNION, then the loop will execute once for the subquery.
@@ -3467,6 +3468,8 @@ bool st_select_lex::optimize_unflattened_subqueries(bool const_only)
           inner_join->select_options|= SELECT_DESCRIBE;
         }
         res= inner_join->optimize();
+        sl->update_correlated_cache();
+        is_correlated_unit|= sl->is_correlated;
         inner_join->select_options= save_options;
         un->thd->lex->current_select= save_select;
         if (empty_union_result)
@@ -3482,6 +3485,9 @@ bool st_select_lex::optimize_unflattened_subqueries(bool const_only)
       }
       if (empty_union_result)
         subquery_predicate->no_rows_in_result();
+      if (!is_correlated_unit)
+        un->uncacheable&= ~UNCACHEABLE_DEPENDENT;
+      subquery_predicate->is_correlated= is_correlated_unit;
     }
   }
   return FALSE;
@@ -3850,6 +3856,61 @@ void SELECT_LEX::update_used_tables()
 }
 
 
+/**
+  @brief
+  Update is_correlated cache for this select
+
+  @details
+*/
+
+void st_select_lex::update_correlated_cache()
+{
+  TABLE_LIST *tl;
+  List_iterator<TABLE_LIST> ti(leaf_tables);
+
+  is_correlated= false;
+
+  while ((tl= ti++))
+  {
+    if (tl->on_expr)
+      is_correlated|= test(tl->on_expr->used_tables() & OUTER_REF_TABLE_BIT);
+    for (TABLE_LIST *embedding= tl->embedding ; embedding ;
+         embedding= embedding->embedding)
+    {
+      if (embedding->on_expr)
+        is_correlated|= test(embedding->on_expr->used_tables() &
+                            OUTER_REF_TABLE_BIT);
+    }
+  }
+
+  if (join->conds)
+    is_correlated|= test(join->conds->used_tables() & OUTER_REF_TABLE_BIT);
+
+  if (join->having)
+    is_correlated|= test(join->having->used_tables() & OUTER_REF_TABLE_BIT);
+
+  if (join->tmp_having)
+    is_correlated|= test(join->tmp_having->used_tables() & OUTER_REF_TABLE_BIT);
+
+  Item *item;
+  List_iterator_fast<Item> it(join->fields_list);
+  while ((item= it++))
+    is_correlated|= test(item->used_tables() & OUTER_REF_TABLE_BIT);
+
+  for (ORDER *order= group_list.first; order; order= order->next)
+    is_correlated|= test((*order->item)->used_tables() & OUTER_REF_TABLE_BIT);
+
+  if (!master_unit()->is_union())
+  {
+    for (ORDER *order= order_list.first; order; order= order->next)
+      is_correlated|= test((*order->item)->used_tables() & OUTER_REF_TABLE_BIT);
+  }
+
+  if (!is_correlated)
+    uncacheable&= ~UNCACHEABLE_DEPENDENT;
+}
+
+
 /**
   Set the EXPLAIN type for this subquery.
 */
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 922386151f8..bcc07f98586 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -1018,6 +1018,7 @@ public:
   void mark_as_belong_to_derived(TABLE_LIST *derived);
   void increase_derived_records(ha_rows records);
   void update_used_tables();
+  void update_correlated_cache();
   void mark_const_derived(bool empty);
 
   bool save_leaf_tables(THD *thd);

From 7ddd5418d01e60dba2ae69a668e7c9f811613451 Mon Sep 17 00:00:00 2001
From: unknown <timour@askmonty.org>
Date: Fri, 1 Jun 2012 14:10:15 +0300
Subject: [PATCH 5/5] Fixed bug MDEV-288 CHEAP SQ: Valgrind warnings "Memory
 lost" with IN and EXISTS nested subquery, materialization+semijoin

Analysis:
The memory leak was a result of the interaction of semi-join optimization
with early optimization of constant subqueries. The function:
setup_jtbm_semi_joins() created a dummy temporary table "dummy_table"
in order to make some JOIN_TAB objects complete. Normally, such temporary
tables are freed inside JOIN_TAB::cleanup.

However, the inner-most subquery is pre-optimized, which allows the
optimization fo the MAX subquery to determine that its WHERE is TRUE,
and thus to compute the result of the MAX during optimization. This
ultimately allows the optimize phase of the outer query to find that
it WHERE clause is FALSE. Once JOIN::optimize finds that the result
set is empty, it sets zero_result_cause, and returns *before* it ever
reached make_join_statistics(). As a result the query plan has no
JOIN_TABs at all. Since the temporary table is supposed to be cleanup
via JOIN_TAB::cleanup, this never happens because there is no JOIN_TAB
for this table. Hence we get a memory leak.

Solution:
Whenever there are no JOIN_TABs, iterate over all table reference in
JOIN::join_list, and free the ones that contain semi-join temporary
tables.
---
 mysql-test/r/subselect.result             | 16 ++++++++++++++++
 mysql-test/r/subselect_no_mat.result      | 16 ++++++++++++++++
 mysql-test/r/subselect_no_opts.result     | 16 ++++++++++++++++
 mysql-test/r/subselect_no_scache.result   | 16 ++++++++++++++++
 mysql-test/r/subselect_no_semijoin.result | 16 ++++++++++++++++
 mysql-test/t/subselect.test               | 17 +++++++++++++++++
 sql/sql_select.cc                         | 16 ++++++++++++++++
 7 files changed, 113 insertions(+)

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index c90596315e1..bce5afaec43 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -6700,5 +6700,21 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	16
 drop table t1, t2, t3;
+#
+# MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * 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
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+a
+drop table t1,t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 0722ca7ba88..4ffb4600f77 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -6698,6 +6698,22 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	16
 drop table t1, t2, t3;
+#
+# MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+a
+drop table t1,t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 27cf1f70864..c8251f67d2a 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -6695,6 +6695,22 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	16
 drop table t1, t2, t3;
+#
+# MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * 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
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+a
+drop table t1,t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index 9994ede79de..07652189bfe 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -6706,6 +6706,22 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	16
 drop table t1, t2, t3;
+#
+# MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * 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
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+a
+drop table t1,t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set optimizer_switch=default;
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index 1973262cdaf..ecef51beb07 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -6695,6 +6695,22 @@ Handler_read_rnd	0
 Handler_read_rnd_deleted	0
 Handler_read_rnd_next	16
 drop table t1, t2, t3;
+#
+# MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * 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
+2	MATERIALIZED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
+3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+a
+drop table t1,t2;
 # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
 set @optimizer_switch_for_subselect_test=null;
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index 1cbb15b0b95..1074416cea6 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -5624,5 +5624,22 @@ show status like '%Handler_read%';
 
 drop table t1, t2, t3;
 
+--echo #
+--echo # MDEV-288 CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
+--echo #
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (0),(8);
+
+CREATE TABLE t2 (b INT PRIMARY KEY);
+INSERT INTO t2 VALUES (1),(2);
+
+EXPLAIN
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+SELECT * FROM t1 WHERE 4 IN (SELECT MAX(b) FROM t2 WHERE EXISTS (SELECT * FROM t1));
+
+drop table t1,t2;
+
+
 --echo # return optimizer switch changed in the beginning of this test
 set optimizer_switch=@subselect_tmp;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 10c841639a9..865f3a9d425 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -10595,6 +10595,22 @@ void JOIN::cleanup(bool full)
         tmp_join->tmp_table_param.save_copy_field= 0;
     }
     tmp_table_param.cleanup();
+
+    if (!join_tab)
+    {
+      List_iterator<TABLE_LIST> li(*join_list);
+      TABLE_LIST *table_ref;
+      while ((table_ref= li++))
+      {
+        if (table_ref->table &&
+            table_ref->jtbm_subselect &&
+            table_ref->jtbm_subselect->is_jtbm_const_tab)
+        {
+          free_tmp_table(thd, table_ref->table);
+          table_ref->table= NULL;
+        }
+      }
+    }
   }
   DBUG_VOID_RETURN;
 }