Semi-join optimizations code cleanup part 2:

- Make EXPLAIN display "Start temporary" at the start of the fanout (it used to display
  at the first table whose rowid gets into temp. table which is not that useful for
  the user)
- Updated test results (all checked)

mysql-test/r/subselect.result

@@ -5146,8 +5146,8 @@ explain SELECT * FROM ot1,ot4
 WHERE (ot1.a,ot4.a) IN (SELECT it2.a,it3.a
 FROM it2,it3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
 1	PRIMARY	ot4	ALL	NULL	NULL	NULL	NULL	8	Using where; End temporary; Using join buffer (flat, BNL join)
 DROP TABLE IF EXISTS ot1, ot4, it2, it3;
@@ -5192,8 +5192,8 @@ INSERT INTO t2 VALUES (12,2);
 INSERT INTO t2 VALUES (15,4);
 EXPLAIN SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Start temporary
-1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	Using index; End temporary
 SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 pk	i

mysql-test/r/subselect3.result

@@ -1045,8 +1045,8 @@ explain
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-2	DEPENDENT SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	Z	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 subq
 NULL
@@ -1186,27 +1186,27 @@ insert into t3 select * from t1;
 insert into t3 values (1),(2);
 explain select * from t2 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 explain select * from t2 where a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 explain select * from t2 where a in (select a from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 explain select * from t1 where a in (select a from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 drop table t1, t2, t3;
 create table t1 (a decimal);
 insert into t1 values (1),(2);
 explain select * from t1 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 drop table t1;
 set @@optimizer_switch=@save_optimizer_switch;
 create table t1 (a int);
@@ -1216,8 +1216,8 @@ create table t3 (a int, b int, filler char(100), key(a));
 insert into t3 select A.a + 10*B.a, A.a + 10*B.a, 'filler' from t1 A, t1 B, t1 C;
 explain select * from t1, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30) and t1.a =3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	End temporary
 explain select straight_join * from t1 A, t1 B where A.a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -1276,14 +1276,14 @@ insert into t2 select A.a + 10*B.a, A.a + 10*B.a from t0 A, t0 B;
 set @@optimizer_switch='firstmatch=off';
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	100	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	100	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 set @save_optimizer_search_depth=@@optimizer_search_depth;
 set @@optimizer_search_depth=63;
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	100	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	100	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 set @@optimizer_search_depth=@save_optimizer_search_depth;
 set @@optimizer_switch=@save_optimizer_switch;
 drop table t0, t1, t2;
@@ -1293,8 +1293,8 @@ create table t1 as select * from t0;
 insert into t1 select * from t0;
 explain select * from t0 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 select * from t0 where a in (select a from t1);
 a
 10.24
@@ -1306,8 +1306,8 @@ create table t1 as select * from t0;
 insert into t1 select * from t0;
 explain select * from t0 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 select * from t0 where a in (select a from t1);
 a
 2008-01-01
@@ -1320,8 +1320,8 @@ create table t2 as select a as a, a as b from t0 where a < 3;
 insert into t2 select * from t2;
 explain select * from t1 where (a,b,c) in (select X.a, Y.a, Z.a from t2 X, t2 Y, t2 Z where X.b=33);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Start temporary
-1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	6	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	Y	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	Z	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
 drop table t0,t1,t2;

mysql-test/r/subselect3_jcl6.result

@@ -1054,8 +1054,8 @@ explain
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	X	ALL	NULL	NULL	NULL	NULL	2	
-2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-2	DEPENDENT SUBQUERY	Z	hash_ALL	NULL	#hash#$hj	5	test.Y.a	2	Using where; End temporary; Using join buffer (flat, BNLH join)
+2	DEPENDENT SUBQUERY	Y	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	Z	hash_ALL	NULL	#hash#$hj	5	test.Y.a	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 select (select max(Y.a) from t1 Y where a in (select a from t1 Z) and a < X.a) as subq from t1 X;
 subq
 NULL
@@ -1195,27 +1195,27 @@ insert into t3 select * from t1;
 insert into t3 values (1),(2);
 explain select * from t2 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t2.a	4	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t2.a	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 explain select * from t2 where a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t2.a	2	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t2.a	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 explain select * from t2 where a in (select a from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 explain select * from t1 where a in (select a from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	6	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 drop table t1, t2, t3;
 create table t1 (a decimal);
 insert into t1 values (1),(2);
 explain select * from t1 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	6	test.t1.a	2	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	6	test.t1.a	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 drop table t1;
 set @@optimizer_switch=@save_optimizer_switch;
 create table t1 (a int);
@@ -1225,8 +1225,8 @@ create table t3 (a int, b int, filler char(100), key(a));
 insert into t3 select A.a + 10*B.a, A.a + 10*B.a, 'filler' from t1 A, t1 B, t1 C;
 explain select * from t1, t3 where t3.a in (select a from t2) and (t3.a < 10 or t3.a >30) and t1.a =3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ref	a	a	5	test.t2.a	10	End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 explain select straight_join * from t1 A, t1 B where A.a in (select a from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -1285,14 +1285,14 @@ insert into t2 select A.a + 10*B.a, A.a + 10*B.a from t0 A, t0 B;
 set @@optimizer_switch='firstmatch=off';
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary
-1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	10	test.t1.a,test.t1.b	100	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	10	test.t1.a,test.t1.b	100	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 set @save_optimizer_search_depth=@@optimizer_search_depth;
 set @@optimizer_search_depth=63;
 explain select * from t1 where (a,b) in (select a,b from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary
-1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	10	test.t1.a,test.t1.b	100	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	10	test.t1.a,test.t1.b	100	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 set @@optimizer_search_depth=@save_optimizer_search_depth;
 set @@optimizer_switch=@save_optimizer_switch;
 drop table t0, t1, t2;
@@ -1302,8 +1302,8 @@ create table t1 as select * from t0;
 insert into t1 select * from t0;
 explain select * from t0 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	3	test.t0.a	4	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	3	test.t0.a	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 select * from t0 where a in (select a from t1);
 a
 10.24
@@ -1315,8 +1315,8 @@ create table t1 as select * from t0;
 insert into t1 select * from t0;
 explain select * from t0 where a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t0.a	4	Using where; End temporary; Using join buffer (flat, BNLH join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	t1	hash_ALL	NULL	#hash#$hj	4	test.t0.a	4	Using where; Start temporary; End temporary; Using join buffer (flat, BNLH join)
 select * from t0 where a in (select a from t1);
 a
 2008-01-01
@@ -1329,8 +1329,8 @@ create table t2 as select a as a, a as b from t0 where a < 3;
 insert into t2 select * from t2;
 explain select * from t1 where (a,b,c) in (select X.a, Y.a, Z.a from t2 X, t2 Y, t2 Z where X.b=33);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary
-1	PRIMARY	X	hash_ALL	NULL	#hash#$hj	5	test.t1.a	6	Using where; Using join buffer (flat, BNLH join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	PRIMARY	X	hash_ALL	NULL	#hash#$hj	5	test.t1.a	6	Using where; Start temporary; Using join buffer (flat, BNLH join)
 1	PRIMARY	Y	hash_ALL	NULL	#hash#$hj	5	test.t1.b	6	Using where; Using join buffer (incremental, BNLH join)
 1	PRIMARY	Z	hash_ALL	NULL	#hash#$hj	5	test.t1.c	6	Using where; End temporary; Using join buffer (incremental, BNLH join)
 drop table t0,t1,t2;

mysql-test/r/subselect_extra.result

@@ -12,16 +12,16 @@ insert into t2 values ('2001-01-01 1:1:1'), ('2001-01-01 1:1:1');
 flush tables;
 EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 flush tables;
 SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
 dt
 flush tables;
 EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 flush tables;
 SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
 dt
@@ -64,8 +64,8 @@ explain extended
 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	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary
-1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 Warnings:
 Note	1276	Field or reference 'test.t1.cur_date' of SELECT #2 was resolved in SELECT #1
 Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`cur_date` AS `cur_date` from `test`.`t1` semi join (`test`.`t1` `x1`) where ((`test`.`x1`.`id` = `test`.`t1`.`id`) and (`test`.`t1`.`cur_date` = 0))
@@ -76,8 +76,8 @@ explain extended
 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	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary
-1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 Warnings:
 Note	1276	Field or reference 'test.t2.cur_date' of SELECT #2 was resolved in SELECT #1
 Note	1003	select `test`.`t2`.`id` AS `id`,`test`.`t2`.`cur_date` AS `cur_date` from `test`.`t2` semi join (`test`.`t2` `x1`) where ((`test`.`x1`.`id` = `test`.`t2`.`id`) and (`test`.`t2`.`cur_date` = 0))
@@ -427,8 +427,8 @@ WHERE t3.b IN (SELECT v1.b FROM  v1, t2
 WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary
-1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	3	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	3	
 SELECT * FROM t3 
 WHERE t3.b IN (SELECT v1.b FROM  v1, t2 

mysql-test/r/subselect_no_mat.result

@@ -5151,8 +5151,8 @@ explain SELECT * FROM ot1,ot4
 WHERE (ot1.a,ot4.a) IN (SELECT it2.a,it3.a
 FROM it2,it3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
 1	PRIMARY	ot4	ALL	NULL	NULL	NULL	NULL	8	Using where; End temporary; Using join buffer (flat, BNL join)
 DROP TABLE IF EXISTS ot1, ot4, it2, it3;
@@ -5197,8 +5197,8 @@ INSERT INTO t2 VALUES (12,2);
 INSERT INTO t2 VALUES (15,4);
 EXPLAIN SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Start temporary
-1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	Using index; End temporary
 SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 pk	i

mysql-test/r/subselect_no_scache.result

@@ -5150,8 +5150,8 @@ explain SELECT * FROM ot1,ot4
 WHERE (ot1.a,ot4.a) IN (SELECT it2.a,it3.a
 FROM it2,it3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	ot1	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	it2	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it3	ALL	NULL	NULL	NULL	NULL	6	Using join buffer (flat, BNL join)
 1	PRIMARY	ot4	ALL	NULL	NULL	NULL	NULL	8	Using where; End temporary; Using join buffer (flat, BNL join)
 DROP TABLE IF EXISTS ot1, ot4, it2, it3;
@@ -5196,8 +5196,8 @@ INSERT INTO t2 VALUES (12,2);
 INSERT INTO t2 VALUES (15,4);
 EXPLAIN SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Start temporary
-1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	3	
+1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	it	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	Using index; End temporary
 SELECT * FROM t1 WHERE pk IN (SELECT it.pk FROM t2 JOIN t2 AS it ON 1);
 pk	i

mysql-test/r/subselect_sj.result

@@ -1046,9 +1046,9 @@ WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
 AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; FirstMatch(t3)
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1237,8 +1237,8 @@ A.t1field IN (SELECT A.t1field FROM t2 B) AND
 A.t1field IN (SELECT C.t2field FROM t2 C 
 WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index; Start temporary
-1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; End temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 SELECT * FROM t1 A 
@@ -1266,10 +1266,10 @@ explain
 select * from t1 A, t1 B
 where A.a = B.a and A.a in (select a from t2 C) and B.a in (select a from t2 D);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	Start temporary
+1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	
+1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	D	ALL	NULL	NULL	NULL	NULL	3	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	D	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 drop table t1, t2;
 # 
 # BUG#784441: Abort on semijoin with a view as the inner table
@@ -1431,8 +1431,8 @@ set optimizer_switch='firstmatch=off,loosescan=off,materialization=off';
 explain 
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; End temporary
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 a
@@ -1490,8 +1490,8 @@ explain
 select * from t0 
 where a in (select t1.a from t1 left join (t3 join t2 on t3.b=t2.b) on t1.a=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; End temporary
 select * from t0 
@@ -1508,8 +1508,8 @@ explain
 select * from t0 
 where a in (select t1.a from t1 left join (t3 join t2 on t3.b=t2.b) on t1.a=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary
 select * from t0 
@@ -1703,10 +1703,10 @@ INSERT INTO t4 VALUES (0),(NULL);
 explain 
 SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE IFNULL(t2.f3,'foo') IN (SELECT * FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Start temporary
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3 ) WHERE IFNULL(t2.f3,'foo') IN (SELECT * FROM t4);
 f1	f2	f3	f3
 2	0	0	0
@@ -1764,9 +1764,9 @@ INSERT INTO t3 VALUES (6,5),(6,2),(8,0),(9,1),(6,5);
 explain 
 SELECT * FROM t1, t2 WHERE (t2.a , t1.b) IN (SELECT a, b FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using index; Using join buffer (flat, BNL join)
-1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	5	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	5	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 SELECT * FROM t1, t2 WHERE (t2.a , t1.b) IN (SELECT a, b FROM t3);
 b	a
 5	6
@@ -1869,10 +1869,10 @@ alias1.c IN (SELECT SQ3_alias1.b
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	Start temporary
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	
 1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
-1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary; Using join buffer (flat, BNL join)
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	20	
 create table t3 as

mysql-test/r/subselect_sj2.result

 set @subselect_sj2_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
-drop table if exists t0, t1, t2, t3;
+drop table if exists t0, t1, t2, t3, t4, t5;
 drop view if exists v1;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -864,10 +864,10 @@ EXPLAIN
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	Start temporary
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);

mysql-test/r/subselect_sj2_jcl6.result

@@ -10,7 +10,7 @@ join_cache_level	6
 set @subselect_sj2_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
-drop table if exists t0, t1, t2, t3;
+drop table if exists t0, t1, t2, t3, t4, t5;
 drop view if exists v1;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -875,10 +875,10 @@ EXPLAIN
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	Using where; Start temporary
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	Using where
 1	PRIMARY	t2	hash_ALL	NULL	#hash#$hj	5	test.t3.a	1	Using where; Using join buffer (flat, BNLH join)
 1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (incremental, BNL join)
-1	PRIMARY	t4	hash_ALL	NULL	#hash#$hj	5	test.t3.b	2	Using where; End temporary; Using join buffer (incremental, BNLH join)
+1	PRIMARY	t4	hash_ALL	NULL	#hash#$hj	5	test.t3.b	2	Using where; Start temporary; End temporary; Using join buffer (incremental, BNLH join)
 3	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	1	
 SELECT * FROM t3 LEFT JOIN (v1,t2) ON t3.a = t2.a
 WHERE t3.b IN (SELECT b FROM t4);

mysql-test/r/subselect_sj2_mat.result

@@ -3,7 +3,7 @@ set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
 set @subselect_sj2_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
-drop table if exists t0, t1, t2, t3;
+drop table if exists t0, t1, t2, t3, t4, t5;
 drop view if exists v1;
 create table t0 (a int);
 insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -333,8 +333,8 @@ WHERE Language='English' AND Percentage > 10 AND
 t2.Population > 100000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Rowid-ordered scan; Start temporary
-1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t1.Country	1	Using where
-1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where; End temporary
+1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t1.Country	1	Using where; End temporary
+1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where
 set optimizer_switch=@bug35674_save_optimizer_switch;
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (

mysql-test/r/subselect_sj_jcl6.result

@@ -1057,9 +1057,9 @@ WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
 AND t1.val IN (SELECT t3.val FROM t3
 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Start temporary
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; End temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; FirstMatch(t3); Using join buffer (incremental, BNL join)
 SELECT *
 FROM t1
 WHERE t1.val IN (SELECT t2.val FROM t2
@@ -1248,8 +1248,8 @@ A.t1field IN (SELECT A.t1field FROM t2 B) AND
 A.t1field IN (SELECT C.t2field FROM t2 C 
 WHERE C.t2field IN (SELECT D.t2field FROM t2 D));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index; Start temporary
-1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	A	index	PRIMARY	PRIMARY	4	NULL	3	Using index
+1	PRIMARY	B	index	NULL	PRIMARY	4	NULL	3	Using index; Start temporary; End temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	C	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 1	PRIMARY	D	eq_ref	PRIMARY	PRIMARY	4	test.A.t1field	1	Using index
 SELECT * FROM t1 A 
@@ -1277,10 +1277,10 @@ explain
 select * from t1 A, t1 B
 where A.a = B.a and A.a in (select a from t2 C) and B.a in (select a from t2 D);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	Start temporary
-1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (incremental, BNL join)
-1	PRIMARY	D	ALL	NULL	NULL	NULL	NULL	3	Using where; End temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	3	
+1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
+1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (incremental, BNL join)
+1	PRIMARY	D	ALL	NULL	NULL	NULL	NULL	3	Using where; Start temporary; End temporary; Using join buffer (incremental, BNL join)
 drop table t1, t2;
 # 
 # BUG#784441: Abort on semijoin with a view as the inner table
@@ -1442,8 +1442,8 @@ set optimizer_switch='firstmatch=off,loosescan=off,materialization=off';
 explain 
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; End temporary; Using join buffer (incremental, BNL join)
 select * from t0 where a in (select t1.a from t1 left join t2 on t1.a=t2.a);
 a
@@ -1501,8 +1501,8 @@ explain
 select * from t0 
 where a in (select t1.a from t1 left join (t3 join t2 on t3.b=t2.b) on t1.a=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; End temporary; Using join buffer (incremental, BNL join)
 select * from t0 
@@ -1519,8 +1519,8 @@ explain
 select * from t0 
 where a in (select t1.a from t1 left join (t3 join t2 on t3.b=t2.b) on t1.a=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	Start temporary
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	2	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (incremental, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (incremental, BNL join)
 select * from t0 
@@ -1714,10 +1714,10 @@ INSERT INTO t4 VALUES (0),(NULL);
 explain 
 SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3) WHERE IFNULL(t2.f3,'foo') IN (SELECT * FROM t4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Start temporary
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (incremental, BNL join)
-1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; End temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	2	Using where; Start temporary; End temporary; Using join buffer (incremental, BNL join)
 SELECT * FROM t1 NATURAL LEFT JOIN (t2, t3 ) WHERE IFNULL(t2.f3,'foo') IN (SELECT * FROM t4);
 f1	f2	f3	f3
 2	0	0	0
@@ -1775,9 +1775,9 @@ INSERT INTO t3 VALUES (6,5),(6,2),(8,0),(9,1),(6,5);
 explain 
 SELECT * FROM t1, t2 WHERE (t2.a , t1.b) IN (SELECT a, b FROM t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Start temporary
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using index; Using join buffer (flat, BNL join)
-1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	5	Using where; End temporary; Using join buffer (incremental, BNL join)
+1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	5	Using where; Start temporary; End temporary; Using join buffer (incremental, BNL join)
 SELECT * FROM t1, t2 WHERE (t2.a , t1.b) IN (SELECT a, b FROM t3);
 b	a
 5	6
@@ -1880,10 +1880,10 @@ alias1.c IN (SELECT SQ3_alias1.b
 FROM t2 AS SQ3_alias1 STRAIGHT_JOIN t2 AS SQ3_alias2)
 LIMIT 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	Start temporary
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	20	
 1	PRIMARY	alias2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	20	Using join buffer (incremental, BNL join)
-1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Using join buffer (incremental, BNL join)
+1	PRIMARY	SQ3_alias1	ALL	NULL	NULL	NULL	NULL	20	Using where; Start temporary; Using join buffer (incremental, BNL join)
 1	PRIMARY	SQ3_alias2	index	NULL	PRIMARY	4	NULL	20	Using index; End temporary; Using join buffer (incremental, BNL join)
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	20	
 create table t3 as
@@ -2050,8 +2050,8 @@ explain
 SELECT * FROM t0 WHERE t0.a IN 
 (SELECT t1.a FROM t1, t2 WHERE t2.a=t0.a AND t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	Using where; Start temporary
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	Start temporary; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
 1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	Using where; End temporary; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
 SELECT * FROM t0 WHERE t0.a IN 
 (SELECT t1.a FROM t1, t2 WHERE t2.a=t0.a AND t1.b=t2.b);

mysql-test/t/subselect_sj2.test

@@ -7,7 +7,7 @@ set @subselect_sj2_tmp= @@optimizer_switch;
 set optimizer_switch='semijoin=on,firstmatch=on,loosescan=on';
 set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
 --disable_warnings
-drop table if exists t0, t1, t2, t3;
+drop table if exists t0, t1, t2, t3, t4, t5;
 drop view if exists v1;
 --enable_warnings
 

sql/opt_subselect.cc

@@ -2168,7 +2168,8 @@ bool find_eq_ref_candidate(TABLE *table, table_map sj_inner_tables)
     See setup_semijoin_dups_elimination() for a description of what kinds of
     join prefixes each strategy can handle.
 */
-bool is_multiple_semi_joins(POSITION *prefix, uint idx, table_map inner_tables)
+
+bool is_multiple_semi_joins(JOIN *join, POSITION *prefix, uint idx, table_map inner_tables)
 {
   for (int i= (int)idx; i >= 0; i--)
   {
@@ -2176,7 +2177,8 @@ bool is_multiple_semi_joins(POSITION *prefix, uint idx, table_map inner_tables)
     if ((emb_sj_nest= prefix[i].table->emb_sj_nest))
     {
       if (inner_tables & emb_sj_nest->sj_inner_tables)
-        return !test(inner_tables == emb_sj_nest->sj_inner_tables);
+        return !test(inner_tables == (emb_sj_nest->sj_inner_tables &
+                                      ~join->const_table_map));
     }
   }
   return FALSE;
@@ -2206,6 +2208,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
        - attempts to build semi-join strategies here will confuse
          the optimizer, so bail out.
     */
+    pos->sj_strategy= SJ_OPT_NONE;
     return;
   }
 
@@ -2290,7 +2293,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
           join->cur_dups_producing_tables &= ~handled_fanout;
           //TODO: update bitmap of semi-joins that were handled together with
           // others.
-          if (is_multiple_semi_joins(join->positions, idx, handled_fanout))
+          if (is_multiple_semi_joins(join, join->positions, idx, handled_fanout))
             pos->inner_tables_handled_with_other_sjs |= handled_fanout;
         }
         else
@@ -3906,6 +3909,80 @@ int do_sj_dups_weedout(THD *thd, SJ_TMP_TABLE *sjtbl)
 }
 
 
+int init_dups_weedout(JOIN *join, uint first_table, int first_fanout_table, uint n_tables)
+{
+  THD *thd= join->thd;
+  DBUG_ENTER("init_dups_weedout");
+  SJ_TMP_TABLE::TAB sjtabs[MAX_TABLES];
+  SJ_TMP_TABLE::TAB *last_tab= sjtabs;
+  uint jt_rowid_offset= 0; // # tuple bytes are already occupied (w/o NULL bytes)
+  uint jt_null_bits= 0;    // # null bits in tuple bytes
+  /*
+    Walk through the range and remember
+     - tables that need their rowids to be put into temptable
+     - the last outer table
+  */
+  for (JOIN_TAB *j=join->join_tab + first_table; 
+       j < join->join_tab + first_table + n_tables; j++)
+  {
+    if (sj_table_is_included(join, j))
+    {
+      last_tab->join_tab= j;
+      last_tab->rowid_offset= jt_rowid_offset;
+      jt_rowid_offset += j->table->file->ref_length;
+      if (j->table->maybe_null)
+      {
+        last_tab->null_byte= jt_null_bits / 8;
+        last_tab->null_bit= jt_null_bits++;
+      }
+      last_tab++;
+      j->table->prepare_for_position();
+      j->keep_current_rowid= TRUE;
+    }
+  }
+
+  SJ_TMP_TABLE *sjtbl;
+  if (jt_rowid_offset) /* Temptable has at least one rowid */
+  {
+    size_t tabs_size= (last_tab - sjtabs) * sizeof(SJ_TMP_TABLE::TAB);
+    if (!(sjtbl= (SJ_TMP_TABLE*)thd->alloc(sizeof(SJ_TMP_TABLE))) ||
+        !(sjtbl->tabs= (SJ_TMP_TABLE::TAB*) thd->alloc(tabs_size)))
+      DBUG_RETURN(TRUE); /* purecov: inspected */
+    memcpy(sjtbl->tabs, sjtabs, tabs_size);
+    sjtbl->is_degenerate= FALSE;
+    sjtbl->tabs_end= sjtbl->tabs + (last_tab - sjtabs);
+    sjtbl->rowid_len= jt_rowid_offset;
+    sjtbl->null_bits= jt_null_bits;
+    sjtbl->null_bytes= (jt_null_bits + 7)/8;
+    sjtbl->tmp_table= 
+      create_duplicate_weedout_tmp_table(thd, 
+                                         sjtbl->rowid_len + 
+                                         sjtbl->null_bytes,
+                                         sjtbl);
+    join->sj_tmp_tables.push_back(sjtbl->tmp_table);
+  }
+  else
+  {
+    /* 
+      This is a special case where the entire subquery predicate does 
+      not depend on anything at all, ie this is 
+        WHERE const IN (uncorrelated select)
+    */
+    if (!(sjtbl= (SJ_TMP_TABLE*)thd->alloc(sizeof(SJ_TMP_TABLE))))
+      DBUG_RETURN(TRUE); /* purecov: inspected */
+    sjtbl->tmp_table= NULL;
+    sjtbl->is_degenerate= TRUE;
+    sjtbl->have_degenerate_row= FALSE;
+  }
+
+  sjtbl->next_flush_table= join->join_tab[first_table].flush_weedout_table;
+  join->join_tab[first_table].flush_weedout_table= sjtbl;
+  join->join_tab[first_fanout_table].first_weedout_table= sjtbl;
+  join->join_tab[first_table + n_tables - 1].check_weed_out_table= sjtbl;
+  DBUG_RETURN(0);
+}
+
+
 /*
   Setup the strategies to eliminate semi-join duplicates.
   
@@ -4006,9 +4083,9 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options,
                                     uint no_jbuf_after)
 {
   uint i;
-  THD *thd= join->thd;
   DBUG_ENTER("setup_semijoin_dups_elimination");
-  
+
+
   POSITION *pos= join->best_positions + join->const_tables;
   for (i= join->const_tables ; i < join->top_join_tab_count; )
   {
@@ -4049,6 +4126,7 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options,
           forwards, but do not destroy other duplicate elimination methods.
         */
         uint first_table= i;
+
         uint join_cache_level= join->thd->variables.join_cache_level;
         for (uint j= i; j < i + pos->n_sj_tables; j++)
         {
@@ -4072,70 +4150,7 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options,
           }
         }
 
-        SJ_TMP_TABLE::TAB sjtabs[MAX_TABLES];
-        SJ_TMP_TABLE::TAB *last_tab= sjtabs;
-        uint jt_rowid_offset= 0; // # tuple bytes are already occupied (w/o NULL bytes)
-        uint jt_null_bits= 0;    // # null bits in tuple bytes
-        /*
-          Walk through the range and remember
-           - tables that need their rowids to be put into temptable
-           - the last outer table
-        */
-        for (JOIN_TAB *j=join->join_tab + first_table; 
-             j < join->join_tab + i + pos->n_sj_tables; j++)
-        {
-          if (sj_table_is_included(join, j))
-          {
-            last_tab->join_tab= j;
-            last_tab->rowid_offset= jt_rowid_offset;
-            jt_rowid_offset += j->table->file->ref_length;
-            if (j->table->maybe_null)
-            {
-              last_tab->null_byte= jt_null_bits / 8;
-              last_tab->null_bit= jt_null_bits++;
-            }
-            last_tab++;
-            j->table->prepare_for_position();
-            j->keep_current_rowid= TRUE;
-          }
-        }
-
-        SJ_TMP_TABLE *sjtbl;
-        if (jt_rowid_offset) /* Temptable has at least one rowid */
-        {
-          size_t tabs_size= (last_tab - sjtabs) * sizeof(SJ_TMP_TABLE::TAB);
-          if (!(sjtbl= (SJ_TMP_TABLE*)thd->alloc(sizeof(SJ_TMP_TABLE))) ||
-              !(sjtbl->tabs= (SJ_TMP_TABLE::TAB*) thd->alloc(tabs_size)))
-            DBUG_RETURN(TRUE); /* purecov: inspected */
-          memcpy(sjtbl->tabs, sjtabs, tabs_size);
-          sjtbl->is_degenerate= FALSE;
-          sjtbl->tabs_end= sjtbl->tabs + (last_tab - sjtabs);
-          sjtbl->rowid_len= jt_rowid_offset;
-          sjtbl->null_bits= jt_null_bits;
-          sjtbl->null_bytes= (jt_null_bits + 7)/8;
-          sjtbl->tmp_table= 
-            create_duplicate_weedout_tmp_table(thd, 
-                                               sjtbl->rowid_len + 
-                                               sjtbl->null_bytes,
-                                               sjtbl);
-          join->sj_tmp_tables.push_back(sjtbl->tmp_table);
-        }
-        else
-        {
-          /* 
-            This is a special case where the entire subquery predicate does 
-            not depend on anything at all, ie this is 
-              WHERE const IN (uncorrelated select)
-          */
-          if (!(sjtbl= (SJ_TMP_TABLE*)thd->alloc(sizeof(SJ_TMP_TABLE))))
-            DBUG_RETURN(TRUE); /* purecov: inspected */
-          sjtbl->tmp_table= NULL;
-          sjtbl->is_degenerate= TRUE;
-          sjtbl->have_degenerate_row= FALSE;
-        }
-        join->join_tab[first_table].flush_weedout_table= sjtbl;
-        join->join_tab[i + pos->n_sj_tables - 1].check_weed_out_table= sjtbl;
-
+        init_dups_weedout(join, first_table, i, i + pos->n_sj_tables - first_table);
         i+= pos->n_sj_tables;
         pos+= pos->n_sj_tables;
         break;

sql/opt_subselect.h

@@ -358,8 +358,7 @@ class SJ_TMP_TABLE : public Sql_alloc
   ENGINE_COLUMNDEF *start_recinfo;
   ENGINE_COLUMNDEF *recinfo;
 
-  /* Pointer to next table (next->start_idx > this->end_idx) */
-  SJ_TMP_TABLE *next; 
+  SJ_TMP_TABLE *next_flush_table; 
 };
 
 int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, 

sql/sql_select.cc

@@ -15087,10 +15087,12 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
   int error;
   enum_nested_loop_state rc= NESTED_LOOP_OK;
   READ_RECORD *info= &join_tab->read_record;
-
-  if (join_tab->flush_weedout_table)
+   
+  for (SJ_TMP_TABLE *flush_dups_table= join_tab->flush_weedout_table;
+       flush_dups_table;
+       flush_dups_table= flush_dups_table->next_flush_table)
   {
-    do_sj_reset(join_tab->flush_weedout_table);
+    do_sj_reset(flush_dups_table);
   }
 
   if (!join_tab->preread_init_done && join_tab->preread_init())
@@ -21013,7 +21015,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
           extra.append(STRING_WITH_LEN("; LooseScan"));
         }
 
-        if (tab->flush_weedout_table)
+        if (tab->first_weedout_table)
           extra.append(STRING_WITH_LEN("; Start temporary"));
         if (tab->check_weed_out_table)
           extra.append(STRING_WITH_LEN("; End temporary"));

sql/sql_select.h

@@ -341,6 +341,8 @@ typedef struct st_join_table {
   /* Variables for semi-join duplicate elimination */
   SJ_TMP_TABLE  *flush_weedout_table;
   SJ_TMP_TABLE  *check_weed_out_table;
+  /* for EXPLAIN only: */
+  SJ_TMP_TABLE  *first_weedout_table;
   
   /*
     If set, means we should stop join enumeration after we've got the first