Merge the fix for lp:944706, mdev-193

48 files changed, 1613 insertions, 433 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 a6fa21ad800..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
@@ -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/index_merge_innodb.result b/mysql-test/r/index_merge_innodb.result
index e5025acc998..b8eda092291 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 f16b38772a6..fd2a948847c 100644
--- a/mysql-test/r/join_outer.result
+++ b/mysql-test/r/join_outer.result
@@ -1895,10 +1895,10 @@ 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	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 a4aaaf6085d..d891f5c49b2 100644
--- a/mysql-test/r/join_outer_jcl6.result
+++ b/mysql-test/r/join_outer_jcl6.result
@@ -1906,10 +1906,10 @@ 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	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/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/r/ps.result b/mysql-test/r/ps.result
index 27131438d16..82a944cc81b 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 235d211840f..bb858ecc864 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
@@ -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';
@@ -907,7 +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');
@@ -1608,25 +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;
@@ -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');
@@ -3099,8 +3096,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using where
 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;
@@ -3111,8 +3108,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+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;
@@ -3163,7 +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
@@ -3699,7 +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
@@ -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
@@ -4580,7 +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;
@@ -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
@@ -5969,7 +5966,7 @@ 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)
@@ -6130,7 +6127,7 @@ 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;
 #
@@ -6542,7 +6539,7 @@ 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
@@ -6550,7 +6547,7 @@ 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
@@ -6589,5 +6586,162 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELECT 5) AND f1 = 7;
 f1	f2
 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	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	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;
+#
+# 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;
+#
+# 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;
+#
+# 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/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 617d2e9e592..1e4b6c9df0a 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
@@ -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() 
@@ -1250,10 +1257,9 @@ 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	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	
+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
@@ -1267,17 +1273,16 @@ 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	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	
+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
 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
@@ -1285,10 +1290,9 @@ 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	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	
+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
@@ -1302,10 +1306,9 @@ 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	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	
+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
@@ -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	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);
@@ -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_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_innodb.result b/mysql-test/r/subselect_innodb.result
index 5ee56b25fee..a0f05a26a46 100644
--- a/mysql-test/r/subselect_innodb.result
+++ b/mysql-test/r/subselect_innodb.result
@@ -332,8 +332,8 @@ 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 = (
@@ -361,7 +361,7 @@ 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 >= (
@@ -386,7 +386,7 @@ select 1 from t1 where 1 like (select 1 from t1 where 1 <=> (select 1 from t1 gr
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	
-3	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	Using temporary; Using filesort
+3	SUBQUERY	internal_tmp_table	ALL	group_key	NULL	NULL	NULL	1	Using temporary; Using filesort
 select 1 from t1 where 1 like (select 1 from t1 where 1 <=> (select 1 from t1 group by a1));
 1
 1
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 78472e99326..75cc0089983 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	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	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	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	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	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	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
@@ -2166,7 +2166,7 @@ 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);
@@ -2175,7 +2175,7 @@ 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)
@@ -2192,7 +2192,7 @@ 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)
@@ -2235,10 +2235,10 @@ 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
@@ -2246,10 +2246,10 @@ 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	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.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 ca4aa57417e..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	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
 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 b08148f8057..84fd6a51f6b 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
@@ -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';
@@ -914,7 +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');
@@ -1615,25 +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;
@@ -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');
@@ -3105,8 +3102,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using where
 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;
@@ -3117,8 +3114,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+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;
@@ -3169,7 +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
@@ -3703,7 +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
@@ -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	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	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;
 #
@@ -4582,7 +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;
@@ -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
@@ -5970,7 +5967,7 @@ 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)
@@ -6129,7 +6126,7 @@ 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;
 #
@@ -6541,7 +6538,7 @@ 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
@@ -6549,7 +6546,7 @@ 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
@@ -6588,6 +6585,162 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELECT 5) AND f1 = 7;
 f1	f2
 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	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	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;
+#
+# 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;
+#
+# 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;
+#
+# 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 36d03d8db77..c147271f0f6 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
@@ -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';
@@ -910,7 +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');
@@ -1611,25 +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;
@@ -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');
@@ -3101,8 +3098,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using where
 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;
@@ -3113,8 +3110,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+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;
@@ -3165,7 +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
@@ -3699,7 +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
@@ -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	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	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;
 #
@@ -4578,7 +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;
@@ -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
@@ -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)
@@ -6125,7 +6122,7 @@ 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;
 #
@@ -6537,7 +6534,7 @@ 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
@@ -6545,7 +6542,7 @@ 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
@@ -6584,6 +6581,163 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELECT 5) AND f1 = 7;
 f1	f2
 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	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	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;
+#
+# 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;
+#
+# 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;
+#
+# 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 7fcacfda470..dba1b3f53c0 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
@@ -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';
@@ -913,7 +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');
@@ -1614,25 +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;
@@ -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');
@@ -3105,8 +3102,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using where
 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;
@@ -3117,8 +3114,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+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;
@@ -3169,7 +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
@@ -3705,7 +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
@@ -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
@@ -4586,7 +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;
@@ -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
@@ -5975,7 +5972,7 @@ 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)
@@ -6136,7 +6133,7 @@ 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;
 #
@@ -6548,7 +6545,7 @@ 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
@@ -6556,7 +6553,7 @@ 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
@@ -6595,6 +6592,163 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELECT 5) AND f1 = 7;
 f1	f2
 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	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	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;
+#
+# 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;
+#
+# 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;
+#
+# 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 405261c9ec6..52b01896ac0 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
@@ -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');
@@ -3101,8 +3098,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using where
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+2	SUBQUERY	t2	range	b	b	40	NULL	2	Using where
 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;
@@ -3113,8 +3110,8 @@ 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
-2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	2	Using index condition
+1	PRIMARY	r	const	PRIMARY	PRIMARY	4	const	1	
+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;
@@ -3699,7 +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
@@ -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	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	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;
 #
@@ -4578,7 +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;
@@ -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
@@ -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)
@@ -6125,7 +6122,7 @@ 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;
 #
@@ -6537,7 +6534,7 @@ 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
@@ -6545,7 +6542,7 @@ 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
@@ -6584,6 +6581,163 @@ NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL
 SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELECT 5) AND f1 = 7;
 f1	f2
 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	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	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;
+#
+# 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;
+#
+# 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;
+#
+# 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_sj_mat.result b/mysql-test/r/subselect_sj_mat.result
index e3f73d3993b..49f15f4ec1f 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	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	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	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	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	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	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/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/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index b02b1d4a4a0..1061dd7f480 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');
@@ -5556,5 +5557,116 @@ SELECT SUM(a) AS f1, a AS f2 FROM (t1, t2) HAVING f2 >= ALL (SELECT 4 UNION SELE
 
 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 #
+--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 #
+--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 #
+--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/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index e6ff625d3fe..a560148bdd6 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 a9c1153d236..f7f3edda384 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 5f1a863d8fd..ec22fbebd5b 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -5540,7 +5540,15 @@ 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 de62bc49930..c10ce8525d4 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -371,9 +371,9 @@ 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 5458a2fb968..bbd3bf35a2d 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -523,6 +523,48 @@ 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 0e0f61aedd9..415bb059198 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 a5a68d0d306..8d1cbeba5f4 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -4894,7 +4894,43 @@ 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;
 }
 
 
@@ -5295,7 +5331,14 @@ 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 c88d8211986..f9fb23153b3 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 ba189d89ccb..73047663981 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -3406,7 +3406,23 @@ 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())
   {
@@ -3416,12 +3432,19 @@ 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;
+      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.
@@ -3446,6 +3469,8 @@ bool st_select_lex::optimize_unflattened_subqueries()
           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)
@@ -3461,6 +3486,9 @@ bool st_select_lex::optimize_unflattened_subqueries()
       }
       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;
@@ -3830,6 +3858,61 @@ 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 7da0cc48298..10be195feba 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);
@@ -1023,6 +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);
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 223e5c44fcf..6d6acb4eb04 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -271,6 +271,8 @@ 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.
@@ -987,7 +989,10 @@ 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 */
@@ -1274,6 +1279,12 @@ 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,
@@ -1294,6 +1305,12 @@ 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();
     }
   }
@@ -6615,6 +6632,32 @@ 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()
+{
+  ha_rows examined_rows;
+  double prev_fanout= 1;
+  JOIN_TAB *tab= first_breadth_first_tab(this);
+  JOIN_TAB *prev_tab= tab;
+
+  examined_rows= tab->get_examined_rows();
+
+  while ((tab= next_breadth_first_tab(this, tab)))
+  {
+    prev_fanout *= prev_tab->records_read;
+    examined_rows+= tab->get_examined_rows() * prev_fanout;
+    prev_tab= tab;
+  }
+  return examined_rows;
+}
+
+
+/**
   Find a good, possibly optimal, query execution plan (QEP) by a possibly
   exhaustive search.
 
@@ -8061,36 +8104,15 @@ 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;
@@ -10288,6 +10310,51 @@ 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.
@@ -10591,6 +10658,22 @@ 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;
 }
@@ -11267,9 +11350,9 @@ 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;
         }  
@@ -11362,9 +11445,9 @@ 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);
     }
@@ -12050,9 +12133,8 @@ 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;
@@ -12139,7 +12221,7 @@ 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,
@@ -18613,6 +18695,7 @@ 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)
@@ -21354,10 +21437,17 @@ 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)
@@ -21515,32 +21605,8 @@ 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 c4553148cc6..0ed976ac36a 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 c8af1422388..b244f75a157 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -3768,4 +3768,9 @@ 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());
 }