Set new default values for the optimizer switch flags 'derived_merge'

and 'derived_with_keys'. Now they are set on by default.

mysql-test/include/index_merge1.inc

@@ -264,7 +264,10 @@ explain select * from t1 where key1=3 or key2=4
   union select * from t1 where key1<4 or key3=5;
 
 #  index merge in subselect
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select * from (select * from t1 where key1 = 3 or key2 =3) as Z where key8 >5;
+set optimizer_switch=@tmp_optimizer_switch;
 
 # 12. check for long index_merges.
 create table t3 like t0;

mysql-test/r/derived.result

 drop table if exists t1,t2,t3;
+set @save_derived_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select * from (select 2 from DUAL) b;
 2
 2
@@ -205,6 +207,7 @@ x
 1
 create user mysqltest_1;
 create table t1 select 1 as a;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select 2 as a from (select * from t1) b;
 ERROR 3D000: No database selected
 use test;
@@ -413,3 +416,4 @@ MIN(i)
 1
 DROP TABLE t1;
 # End of 5.0 tests
+set optimizer_switch=@save_derived_optimizer_switch;

mysql-test/r/explain.result

@@ -309,6 +309,8 @@ End of 5.1 tests.
 CREATE TABLE t1 (a int) ;
 CREATE TABLE t2 (a int) ;
 INSERT INTO t2 VALUES (8);
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN EXTENDED
 SELECT * FROM ( SELECT t1.a FROM t1,t2 WHERE t2.a = t1.a ) AS t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -316,4 +318,5 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 Warnings:
 Note	1003	select NULL AS `a` from (select NULL AS `a` from `test`.`t1` join `test`.`t2` where 0) `t`
+set optimizer_switch=@tmp_optimizer_switch;
 DROP TABLE t1,t2;

mysql-test/r/func_group.result

@@ -1930,6 +1930,8 @@ FROM t2);
 MIN(a)
 NULL
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN 
 SELECT MIN(a)
 FROM (SELECT a FROM empty1) tt
@@ -1940,6 +1942,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+set optimizer_switch=@tmp_optimizer_switch;
 
 #
 # 5) Test that subquery materialization is setup for query with

mysql-test/r/func_str.result

@@ -2547,6 +2547,8 @@ End of 5.0 tests
 drop table if exists t1;
 create table t1(f1 tinyint default null)engine=myisam;
 insert into t1 values (-1),(null);
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select 1 as a from t1,(select decode(f1,f1) as b from t1) a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
@@ -2557,6 +2559,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1;
 #
 # Bug#49141: Encode function is significantly slower in 5.1 compared to 5.0

mysql-test/r/index_merge_innodb.result

@@ -686,6 +686,8 @@ INSERT INTO t1(a,b) SELECT a,b FROM t1;
 INSERT INTO t1(a,b) SELECT a,b FROM t1;
 INSERT INTO t1 VALUES (1000000, 0, 0);
 SET SESSION sort_buffer_size = 1024*36;
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN
 SELECT COUNT(*) FROM 
 (SELECT * FROM t1 FORCE INDEX(primary,idx)
@@ -711,6 +713,7 @@ WHERE a BETWEEN 2 AND 7 OR pk=1000000) AS t;
 COUNT(*)
 6145
 DROP TABLE t1;
+set optimizer_switch=@tmp_optimizer_switch;
 #
 # Testcase Backport: BUG#48093: 6.0 Server not processing equivalent IN clauses properly
 #            with Innodb tables

mysql-test/r/index_merge_myisam.result

@@ -285,10 +285,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	index_merge	i1,i2	i1,i2	4,4	NULL	2	Using union(i1,i2); Using where
 2	UNION	t1	index_merge	i1,i3	i1,i3	4,4	NULL	5	Using sort_union(i1,i3); Using where
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select * from (select * from t1 where key1 = 3 or key2 =3) as Z where key8 >5;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using where
 2	DERIVED	t1	index_merge	i1,i2	i1,i2	4,4	NULL	2	Using union(i1,i2); Using where
+set optimizer_switch=@tmp_optimizer_switch;
 create table t3 like t0;
 insert into t3 select * from t0;
 alter table t3 add key9 int not null, add index i9(key9);

mysql-test/r/information_schema.result

@@ -1277,6 +1277,8 @@ COLUMN_NAME	MD5(COLUMN_DEFAULT)	LENGTH(COLUMN_DEFAULT)	COLUMN_DEFAULT=get_value(
 fld1	7cf7a6782be951a1f2464a350da926a5	65532	1
 DROP TABLE bug23037;
 DROP FUNCTION get_value;
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 create view v1 as
 select table_schema as object_schema,
 table_name   as object_name,
@@ -1290,6 +1292,7 @@ explain select * from (select table_name from information_schema.tables) as a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	NULL	Skip_open_table; Scanned all databases
+set optimizer_switch=@tmp_optimizer_switch;
 drop view v1;
 create table t1 (f1 int(11));
 create table t2 (f1 int(11), f2 int(11));

mysql-test/r/ps.result

@@ -151,6 +151,8 @@ c32 set('monday', 'tuesday', 'wednesday')
 create table t2 like t1;
 set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 set @stmt= ' 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 ' ;
 prepare stmt1 from @stmt ;
 execute stmt1 ;
@@ -178,6 +180,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 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
 deallocate prepare stmt1;
+set optimizer_switch=@tmp_optimizer_switch;
 drop tables t1,t2;
 set @@optimizer_switch=@save_optimizer_switch;
 set @arg00=1;

mysql-test/r/subselect.result

@@ -201,6 +201,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -209,6 +211,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -5536,10 +5539,13 @@ DROP TABLE parent, child;
 CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	t1	ref	a	a	5	const	1	
+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

mysql-test/r/subselect3.result

@@ -1119,12 +1119,15 @@ a
 set @@optimizer_switch=@save_optimizer_switch;
 set @@optimizer_switch=@save_optimizer_switch;
 set @@optimizer_switch='materialization=off';
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select * from (select a from t0) X where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	11	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	20	Using where; FirstMatch(<derived2>); Using join buffer (flat, BNL join)
 2	DERIVED	t0	ALL	NULL	NULL	NULL	NULL	11	
 drop table t0, t1;
+set optimizer_switch=@tmp_optimizer_switch;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
 create table t1 (kp1 int, kp2 int, c int, filler char(100), key(kp1, kp2));

mysql-test/r/subselect3_jcl6.result

@@ -1128,12 +1128,15 @@ a
 set @@optimizer_switch=@save_optimizer_switch;
 set @@optimizer_switch=@save_optimizer_switch;
 set @@optimizer_switch='materialization=off';
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select * from (select a from t0) X where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	11	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	20	Using where; FirstMatch(<derived2>); Using join buffer (flat, BNL join)
 2	DERIVED	t0	ALL	NULL	NULL	NULL	NULL	11	
 drop table t0, t1;
+set optimizer_switch=@tmp_optimizer_switch;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
 create table t1 (kp1 int, kp2 int, c int, filler char(100), key(kp1, kp2));

mysql-test/r/subselect_mat.result

@@ -1337,6 +1337,8 @@ DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a INTEGER);
 CREATE TABLE t2 (b INTEGER);
 INSERT INTO t2 VALUES (1);
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain SELECT a FROM (
 SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a > 3 OR t2.b IN (SELECT a FROM t1)
 ) table1;
@@ -1348,6 +1350,7 @@ SELECT a FROM (
 SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a > 3 OR t2.b IN (SELECT a FROM t1)
 ) table1;
 a
+set optimizer_switch=@tmp_optimizer_switch;
 DROP TABLE t1, t2;
 # End BUG#56367
 #

mysql-test/r/subselect_mat_cost_bugs.result

@@ -156,6 +156,8 @@ drop table t1, t2, t3;
 CREATE TABLE t2 ( f2 int(11)) ;
 CREATE TABLE t1 ( f3 int(11), KEY (f3)) ;
 INSERT INTO t1 VALUES (6),(4);
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN
 SELECT * FROM (SELECT * FROM t2) AS a2
 WHERE (SELECT distinct SUM(distinct f3 ) FROM t1);
@@ -171,6 +173,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 3	SUBQUERY	t1	index	NULL	f3	5	NULL	2	Using index
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2;
 #
 # LP BUG#715027 Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed
@@ -179,6 +182,8 @@ CREATE TABLE t1 ( f1 int(11), PRIMARY KEY (f1)) ;
 INSERT INTO t1 VALUES (28),(29);
 CREATE TABLE t2 ( f2 int(11), f3 int(11), f10 varchar(1)) ;
 INSERT INTO t2 VALUES (NULL,6,'f'),(4,2,'d');
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN
 SELECT alias2.f2 AS field1
 FROM t1 AS alias1 JOIN ( SELECT * FROM t2 ) AS alias2 ON alias2.f3 = alias1.f1
@@ -203,6 +208,7 @@ WHERE t1.f1 AND alias2.f10
 )
 ORDER BY field1 ;
 field1
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2;
 #
 # LP BUG#718578 Yet another Assertion `!table ||

mysql-test/r/subselect_no_mat.result

@@ -206,6 +206,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -214,6 +216,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -5535,10 +5538,13 @@ DROP TABLE parent, child;
 CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	t1	ref	a	a	5	const	1	
+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

mysql-test/r/subselect_no_opts.result

@@ -202,6 +202,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -210,6 +212,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -5531,10 +5534,13 @@ DROP TABLE parent, child;
 CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	t1	ref	a	a	5	const	1	
+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

mysql-test/r/subselect_no_scache.result

@@ -205,6 +205,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -213,6 +215,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -5540,10 +5543,13 @@ DROP TABLE parent, child;
 CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	t1	ref	a	a	5	const	1	
+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

mysql-test/r/subselect_no_semijoin.result

@@ -202,6 +202,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -210,6 +212,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -5531,10 +5534,13 @@ DROP TABLE parent, child;
 CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
 2	DERIVED	t1	ref	a	a	5	const	1	
+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

mysql-test/r/subselect_partial_match.result

@@ -766,6 +766,8 @@ CREATE TABLE t2 (b1 int DEFAULT NULL, b2 int DEFAULT NULL);
 INSERT INTO t2 VALUES (6,NULL);
 INSERT INTO t2 VALUES (NULL,0);
 set @@optimizer_switch='materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on';
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN EXTENDED
 SELECT * FROM (SELECT * FROM t1 WHERE a1 NOT IN (SELECT b2 FROM t2)) table1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -774,6 +776,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	
 Warnings:
 Note	1003	select `table1`.`a1` AS `a1`,`table1`.`a2` AS `a2` from (select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where (not(<in_optimizer>(`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( <materialize> (select `test`.`t2`.`b2` from `test`.`t2` ), <primary_index_lookup>(`test`.`t1`.`a1` in <temporary table> on distinct_key where ((`test`.`t1`.`a1` = `<subquery3>`.`b2`)))))))) `table1`
+set optimizer_switch=@tmp_optimizer_switch;
 DROP TABLE t1, t2;
 #
 # LP BUG#613009 Crash in Ordered_key::get_field_idx

mysql-test/r/subselect_sj.result

@@ -1862,6 +1862,8 @@ INSERT INTO t2 VALUES (1,2,4,'22:34:09','v','v'),
 (16,8,1,'02:57:29',NULL,NULL),(17,3,1,'16:46:13','r','r'),
 (18,3,9,'19:39:02','v','v'),(19,9,1,NULL,NULL,NULL),
 (20,6,5,'20:58:33','r','r');
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 SELECT
 alias1.a, alias1.b, alias1.c, alias1.d, alias1.e, alias1.f,
@@ -1897,6 +1899,7 @@ WHERE
 alias1.c IN (SELECT SQ3_alias1.b 
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2, t3;
 set optimizer_switch=@tmp_830993;
 set join_buffer_size= @tmp_830993_jbs;

mysql-test/r/subselect_sj_jcl6.result

@@ -1873,6 +1873,8 @@ INSERT INTO t2 VALUES (1,2,4,'22:34:09','v','v'),
 (16,8,1,'02:57:29',NULL,NULL),(17,3,1,'16:46:13','r','r'),
 (18,3,9,'19:39:02','v','v'),(19,9,1,NULL,NULL,NULL),
 (20,6,5,'20:58:33','r','r');
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 SELECT
 alias1.a, alias1.b, alias1.c, alias1.d, alias1.e, alias1.f,
@@ -1908,6 +1910,7 @@ WHERE
 alias1.c IN (SELECT SQ3_alias1.b 
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2, t3;
 set optimizer_switch=@tmp_830993;
 set join_buffer_size= @tmp_830993_jbs;

mysql-test/r/subselect_sj_mat.result

@@ -1372,6 +1372,8 @@ DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a INTEGER);
 CREATE TABLE t2 (b INTEGER);
 INSERT INTO t2 VALUES (1);
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain SELECT a FROM (
 SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a > 3 OR t2.b IN (SELECT a FROM t1)
 ) table1;
@@ -1383,6 +1385,7 @@ SELECT a FROM (
 SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a > 3 OR t2.b IN (SELECT a FROM t1)
 ) table1;
 a
+set optimizer_switch=@tmp_optimizer_switch;
 DROP TABLE t1, t2;
 # End BUG#56367
 #

mysql-test/suite/innodb/r/innodb_lock_wait_timeout_1.result

@@ -97,6 +97,8 @@ insert into t1 values (1,1), (2,null), (3,1), (4,1),
 # Demonstrate that for the SELECT statement
 # used later in the test JT_EQ_REF access method is used.
 #
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 2 as a, 1 as b union all
 select 2 as a, 2 as b) as t2 for update;
@@ -150,6 +152,7 @@ key_len	NULL
 ref	NULL
 rows	NULL
 Extra	
+set optimizer_switch=@tmp_optimizer_switch;
 #
 # Demonstrate that the reported SELECT statement
 # no longer produces warnings.
@@ -301,6 +304,8 @@ begin;
 # is retreived and processed first.
 #
 # Verify that JT_EQ_REF is used.
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 3 as a, 2 as b union all
 select 3 as a, 1 as b) as t2 for update;
@@ -354,6 +359,7 @@ key_len	NULL
 ref	NULL
 rows	NULL
 Extra	
+set optimizer_switch=@tmp_optimizer_switch;
 # Lock the record.
 select 1 from t1 natural join (select 3 as a, 2 as b union all
 select 3 as a, 1 as b) as t2 for update;

mysql-test/suite/innodb/t/innodb_lock_wait_timeout_1.test

@@ -140,9 +140,12 @@ insert into t1 values (1,1), (2,null), (3,1), (4,1),
 --echo # used later in the test JT_EQ_REF access method is used.
 --echo #
 --vertical_results
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 2 as a, 1 as b union all
                                select 2 as a, 2 as b) as t2 for update;
+set optimizer_switch=@tmp_optimizer_switch;
 --horizontal_results
 --echo #
 --echo # Demonstrate that the reported SELECT statement
@@ -236,9 +239,12 @@ begin;
 --echo #
 --echo # Verify that JT_EQ_REF is used.
 --vertical_results
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 3 as a, 2 as b union all
                                select 3 as a, 1 as b) as t2 for update;
+set optimizer_switch=@tmp_optimizer_switch;
 --horizontal_results
 --echo # Lock the record.
 select 1 from t1 natural join (select 3 as a, 2 as b union all

mysql-test/suite/innodb_plugin/r/innodb_lock_wait_timeout_1.result

@@ -99,6 +99,7 @@ insert into t1 values (1,1), (2,null), (3,1), (4,1),
 #
 set @tmp_optimizer_switch=@@optimizer_switch;
 set optimizer_switch='index_condition_pushdown=off';
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 2 as a, 1 as b union all
 select 2 as a, 2 as b) as t2 for update;
@@ -306,6 +307,7 @@ begin;
 # Verify that JT_EQ_REF is used.
 set @tmp_optimizer_switch=@@optimizer_switch;
 set optimizer_switch='index_condition_pushdown=off';
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 3 as a, 2 as b union all
 select 3 as a, 1 as b) as t2 for update;

mysql-test/suite/innodb_plugin/t/innodb_lock_wait_timeout_1.test

@@ -142,6 +142,7 @@ insert into t1 values (1,1), (2,null), (3,1), (4,1),
 --vertical_results
 set @tmp_optimizer_switch=@@optimizer_switch;
 set optimizer_switch='index_condition_pushdown=off';
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 2 as a, 1 as b union all
                                select 2 as a, 2 as b) as t2 for update;
@@ -241,6 +242,7 @@ begin;
 --vertical_results
 set @tmp_optimizer_switch=@@optimizer_switch;
 set optimizer_switch='index_condition_pushdown=off';
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain
 select 1 from t1 natural join (select 3 as a, 2 as b union all
                                select 3 as a, 1 as b) as t2 for update;

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

 drop table if exists t1,t2,t3;
+set @save_derived_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select * from (select 2 from DUAL) b;
 2
 2
@@ -208,6 +210,7 @@ create table t1 select 1 as a;
 analyze table t1;
 Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select 2 as a from (select * from t1) b;
 ERROR 3D000: No database selected
 use test;
@@ -389,3 +392,4 @@ select t2.* from (select * from t1) as A inner join t2 on A.ID = t2.FID;
 ID	DATA	FID
 drop table t1, t2;
 drop user mysqltest_1;
+set optimizer_switch=@save_derived_optimizer_switch;

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

@@ -196,6 +196,8 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
 (select * from t2 where a>1) as tt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -204,6 +206,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
 Warnings:
 Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2

mysql-test/suite/pbxt/t/derived.test

@@ -3,6 +3,9 @@
 drop table if exists t1,t2,t3;
 --enable_warnings
 
+set @save_derived_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 select * from (select 2 from DUAL) b;
 -- error 1054
 SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b;
@@ -107,6 +110,7 @@ create table t1 select 1 as a;
 analyze table t1; # PBXT: Required to get a consitent result
 connect (con1,localhost,mysqltest_1,,*NO-ONE*,$MASTER_MYPORT,$MASTER_MYSOCK);
 connection con1;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 --error 1046
 select 2 as a from (select * from t1) b;
 use test;
@@ -283,3 +287,5 @@ drop user mysqltest_1;
 drop database pbxt;
 --enable_query_log
 # End of 4.1 tests
+
+set optimizer_switch=@save_derived_optimizer_switch;

mysql-test/suite/pbxt/t/subselect.test

@@ -80,8 +80,11 @@ explain extended (select * from t2 where t2.b=(select a from t3 order by 1 desc
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
 (select * from t2 where a>1) as tt;
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
 (select * from t2 where a>1) as tt;
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1);

mysql-test/suite/vcol/inc/vcol_select.inc

@@ -84,10 +84,16 @@ eval $s;
 eval explain $s;
 
 --echo # select_type=DERIVED, type=system
+
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 let $s = select * from (select a,b,c from t1) as t11;
 eval $s;
 eval explain $s;
 
+set optimizer_switch=@tmp_optimizer_switch;
+
 --echo ###
 --echo ### Using aggregate functions with/without DISTINCT
 --echo ###

mysql-test/suite/vcol/r/vcol_select_innodb.result

@@ -89,6 +89,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	UNION	t2	ALL	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 # select_type=DERIVED, type=system
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select * from (select a,b,c from t1) as t11;
 a	b	c
 2	-2	-2
@@ -100,6 +102,7 @@ explain select * from (select a,b,c from t1) as t11;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	5	
+set optimizer_switch=@tmp_optimizer_switch;
 ###
 ### Using aggregate functions with/without DISTINCT
 ###

mysql-test/suite/vcol/r/vcol_select_myisam.result

@@ -89,6 +89,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	UNION	t2	system	NULL	NULL	NULL	NULL	1	
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 # select_type=DERIVED, type=system
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 select * from (select a,b,c from t1) as t11;
 a	b	c
 2	-2	-2
@@ -100,6 +102,7 @@ explain select * from (select a,b,c from t1) as t11;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	5	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	5	
+set optimizer_switch=@tmp_optimizer_switch;
 ###
 ### Using aggregate functions with/without DISTINCT
 ###

mysql-test/t/derived.test

@@ -3,6 +3,9 @@
 drop table if exists t1,t2,t3;
 --enable_warnings
 
+set @save_derived_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 select * from (select 2 from DUAL) b;
 -- error 1054
 SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b;
@@ -106,6 +109,7 @@ create user mysqltest_1;
 create table t1 select 1 as a;
 connect (con1,localhost,mysqltest_1,,*NO-ONE*,$MASTER_MYPORT,$MASTER_MYSOCK);
 connection con1;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 --error 1046
 select 2 as a from (select * from t1) b;
 use test;
@@ -315,3 +319,5 @@ WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
 DROP TABLE t1;
 
 --echo # End of 5.0 tests
+
+set optimizer_switch=@save_derived_optimizer_switch;

mysql-test/t/explain.test

@@ -279,8 +279,11 @@ CREATE TABLE t1 (a int) ;
 CREATE TABLE t2 (a int) ;
 INSERT INTO t2 VALUES (8);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN EXTENDED
 SELECT * FROM ( SELECT t1.a FROM t1,t2 WHERE t2.a = t1.a ) AS t;
+set optimizer_switch=@tmp_optimizer_switch;
 
 DROP TABLE t1,t2;
 

mysql-test/t/func_group.test

@@ -1250,12 +1250,15 @@ SELECT v
 FROM t2);
 
 --echo
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN 
 SELECT MIN(a)
 FROM (SELECT a FROM empty1) tt
 HAVING ('m') IN ( 
 SELECT v
 FROM t2);
+set optimizer_switch=@tmp_optimizer_switch;
 
 --echo 
 --echo #

mysql-test/t/func_str.test

@@ -1315,8 +1315,12 @@ drop table if exists t1;
 --enable_warnings
 create table t1(f1 tinyint default null)engine=myisam;
 insert into t1 values (-1),(null); 
+
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select 1 as a from t1,(select decode(f1,f1) as b from t1) a;
 explain select 1 as a from t1,(select encode(f1,f1) as b from t1) a;
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1;
 
 --echo #

mysql-test/t/index_merge_innodb.test

@@ -68,6 +68,8 @@ INSERT INTO t1(a,b) SELECT a,b FROM t1;
 INSERT INTO t1 VALUES (1000000, 0, 0);
 
 SET SESSION sort_buffer_size = 1024*36;
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 
 # We have to use FORCE INDEX here as Innodb gives inconsistent estimates
 # which causes different query plans.
@@ -89,6 +91,7 @@ SELECT COUNT(*) FROM
      WHERE a BETWEEN 2 AND 7 OR pk=1000000) AS t;
 
 DROP TABLE t1;
+set optimizer_switch=@tmp_optimizer_switch;
 
 --echo #
 --echo # Testcase Backport: BUG#48093: 6.0 Server not processing equivalent IN clauses properly

mysql-test/t/information_schema.test

@@ -962,6 +962,8 @@ DROP FUNCTION get_value;
 #
 # Bug#22413 EXPLAIN SELECT FROM view with ORDER BY yield server crash
 #
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 create view v1 as
 select table_schema as object_schema,
        table_name   as object_name,
@@ -970,6 +972,7 @@ from information_schema.tables
 order by object_schema;
 explain select * from v1;
 explain select * from (select table_name from information_schema.tables) as a;
+set optimizer_switch=@tmp_optimizer_switch;
 drop view v1;
 
 #

mysql-test/t/ps.test

@@ -166,12 +166,18 @@ create table t2 like t1;
 set @save_optimizer_switch=@@optimizer_switch;
 set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 set @stmt= ' 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 ' ;
 prepare stmt1 from @stmt ;
 execute stmt1 ;
 execute stmt1 ;
 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;
 deallocate prepare stmt1;
+
+set optimizer_switch=@tmp_optimizer_switch;
+
 drop tables t1,t2;
 
 set @@optimizer_switch=@save_optimizer_switch;

mysql-test/t/subselect.test

@@ -94,8 +94,11 @@ explain extended (select * from t2 where t2.b=(select a from t3 order by 1 desc
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain extended select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
+set optimizer_switch=@tmp_optimizer_switch;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1);
@@ -4648,7 +4651,10 @@ CREATE TABLE t1 (a INT, b INT, INDEX (a));
 INSERT INTO t1 VALUES (3, 10), (2, 20), (7, 10), (5, 20);
 
 --echo
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN SELECT * FROM (SELECT * FROM t1 WHERE a=7) t;
+set optimizer_switch=@tmp_optimizer_switch;
 --echo
 EXPLAIN SELECT * FROM t1 WHERE EXISTS (SELECT * FROM t1 WHERE a=7);
 

mysql-test/t/subselect3.test

@@ -925,8 +925,11 @@ set @@optimizer_switch='materialization=off';
 # 
 # FirstMatch referring to a derived table
 #
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 explain select * from (select a from t0) X where a in (select a from t1);
 drop table t0, t1;
+set optimizer_switch=@tmp_optimizer_switch;
 
 #
 # LooseScan: Check if we can pick it together with range access

mysql-test/t/subselect_mat_cost_bugs.test

@@ -183,6 +183,9 @@ CREATE TABLE t2 ( f2 int(11)) ;
 CREATE TABLE t1 ( f3 int(11), KEY (f3)) ;
 INSERT INTO t1 VALUES (6),(4);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 EXPLAIN
 SELECT * FROM (SELECT * FROM t2) AS a2
 WHERE (SELECT distinct SUM(distinct f3 ) FROM t1);
@@ -192,6 +195,7 @@ EXPLAIN
 SELECT * FROM (SELECT * FROM t2) AS a2
 WHERE (SELECT distinct SUM(distinct f3 ) FROM t1);
 
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2;
 
 --echo #
@@ -204,6 +208,9 @@ INSERT INTO t1 VALUES (28),(29);
 CREATE TABLE t2 ( f2 int(11), f3 int(11), f10 varchar(1)) ;
 INSERT INTO t2 VALUES (NULL,6,'f'),(4,2,'d');
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 EXPLAIN
 SELECT alias2.f2 AS field1
 FROM t1 AS alias1 JOIN ( SELECT * FROM t2 ) AS alias2 ON alias2.f3 = alias1.f1
@@ -223,6 +230,7 @@ WHERE (
 )
 ORDER BY field1 ;
 
+set optimizer_switch=@tmp_optimizer_switch;
 drop table t1,t2;
 
 --echo #

mysql-test/t/subselect_partial_match.test

@@ -622,8 +622,11 @@ INSERT INTO t2 VALUES (NULL,0);
 
 set @@optimizer_switch='materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on';
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 EXPLAIN EXTENDED
 SELECT * FROM (SELECT * FROM t1 WHERE a1 NOT IN (SELECT b2 FROM t2)) table1;
+set optimizer_switch=@tmp_optimizer_switch;
 
 DROP TABLE t1, t2;
 

mysql-test/t/subselect_sj.test

@@ -1690,6 +1690,9 @@ INSERT INTO t2 VALUES (1,2,4,'22:34:09','v','v'),
   (18,3,9,'19:39:02','v','v'),(19,9,1,NULL,NULL,NULL),
   (20,6,5,'20:58:33','r','r');
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+
 explain
 SELECT
   alias1.a, alias1.b, alias1.c, alias1.d, alias1.e, alias1.f,
@@ -1720,6 +1723,8 @@ WHERE
                FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
 
+set optimizer_switch=@tmp_optimizer_switch;
+
 drop table t1,t2, t3;
 set optimizer_switch=@tmp_830993;
 set join_buffer_size= @tmp_830993_jbs;

mysql-test/t/subselect_sj_mat.test

@@ -1022,12 +1022,15 @@ CREATE TABLE t1 (a INTEGER);
 CREATE TABLE t2 (b INTEGER);
 INSERT INTO t2 VALUES (1);
 
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
 let $query =
 SELECT a FROM (
   SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a > 3 OR t2.b IN (SELECT a FROM t1)
 ) table1;
 eval explain $query;
 eval $query;
+set optimizer_switch=@tmp_optimizer_switch;
 
 DROP TABLE t1, t2;
 

sql/mysql_priv.h

@@ -598,6 +598,8 @@ class Default_object_creation_ctx : public Object_creation_ctx
                                     OPTIMIZER_SWITCH_INDEX_MERGE_SORT_UNION | \
                                     OPTIMIZER_SWITCH_INDEX_MERGE_INTERSECT | \
                                     OPTIMIZER_SWITCH_INDEX_COND_PUSHDOWN | \
+                                    OPTIMIZER_SWITCH_DERIVED_MERGE | \
+                                    OPTIMIZER_SWITCH_DERIVED_WITH_KEYS | \
                                     OPTIMIZER_SWITCH_TABLE_ELIMINATION | \
                                     OPTIMIZER_SWITCH_IN_TO_EXISTS | \
                                     OPTIMIZER_SWITCH_MATERIALIZATION | \

sql/mysqld.cc

@@ -482,8 +482,8 @@ static const char *optimizer_switch_str="index_merge=on,index_merge_union=on,"
                                         "index_merge_intersection=on,"
                                         "index_merge_sort_intersection=off,"
                                         "index_condition_pushdown=on,"
-                                        "derived_merge=off,"
-                                        "derived_with_keys=off,"
+                                        "derived_merge=on,"
+                                        "derived_with_keys=on,"
                                         "firstmatch=on,"
                                         "loosescan=on,"
                                         "materialization=on,"