set @save_optimizer_switch_jcl6=@@optimizer_switch;
set @@optimizer_switch='optimize_join_buffer_size=on';
set @@optimizer_switch='semijoin_with_cache=on';
set @@optimizer_switch='outer_join_with_cache=on';
set @@optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
set join_cache_level=6;
show variables like 'join_cache_level';
Variable_name	Value
join_cache_level	6
set @optimizer_switch_for_join_nested_test=@@optimizer_switch;
set @join_cache_level_for_join_nested_test=@@join_cache_level;
DROP TABLE IF EXISTS t0,t1,t2,t3,t4,t5,t6,t7,t8,t9;
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch=ifnull(@optimizer_switch_for_join_nested_test,'outer_join_with_cache=off');
set join_cache_level=@join_cache_level_for_join_nested_test;
CREATE TABLE t0 (a int, b int, c int);
CREATE TABLE t1 (a int, b int, c int);
CREATE TABLE t2 (a int, b int, c int);
CREATE TABLE t3 (a int, b int, c int);
CREATE TABLE t4 (a int, b int, c int);
CREATE TABLE t5 (a int, b int, c int);
CREATE TABLE t6 (a int, b int, c int);
CREATE TABLE t7 (a int, b int, c int);
CREATE TABLE t8 (a int, b int, c int);
CREATE TABLE t9 (a int, b int, c int);
INSERT INTO t0 VALUES (1,1,0), (1,2,0), (2,2,0);
INSERT INTO t1 VALUES (1,3,0), (2,2,0), (3,2,0);
INSERT INTO t2 VALUES (3,3,0), (4,2,0), (5,3,0);
INSERT INTO t3 VALUES (1,2,0), (2,2,0);
INSERT INTO t4 VALUES (3,2,0), (4,2,0);
INSERT INTO t5 VALUES (3,1,0), (2,2,0), (3,3,0);
INSERT INTO t6 VALUES (3,2,0), (6,2,0), (6,1,0);
INSERT INTO t7 VALUES (1,1,0), (2,2,0);
INSERT INTO t8 VALUES (0,2,0), (1,2,0);
INSERT INTO t9 VALUES (1,1,0), (1,2,0), (3,3,0);
SELECT t2.a,t2.b
FROM t2;
a	b
3	3
4	2
5	3
SELECT t3.a,t3.b
FROM t3;
a	b
1	2
2	2
SELECT t4.a,t4.b
FROM t4;
a	b
3	2
4	2
SELECT t3.a,t3.b,t4.a,t4.b
FROM t3,t4;
a	b	a	b
1	2	3	2
2	2	3	2
1	2	4	2
2	2	4	2
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t2.b=t4.b;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	2	2	3	2
4	2	1	2	4	2
4	2	2	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	1	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t2.b=t4.b
WHERE t3.a=1 OR t3.c IS NULL;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) where ((`test`.`t3`.`a` = 1) or isnull(`test`.`t3`.`c`))
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t2.b=t4.b
WHERE t3.a=1 OR t3.c IS NULL;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	1	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
a	b	a	b	a	b
4	2	2	2	3	2
4	2	2	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
SELECT t5.a,t5.b
FROM t5;
a	b
3	1
2	2
3	3
SELECT t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t3,t4,t5;
a	b	a	b	a	b
1	2	3	2	3	1
2	2	3	2	3	1
1	2	4	2	3	1
2	2	4	2	3	1
1	2	3	2	2	2
2	2	3	2	2	2
1	2	4	2	2	2
2	2	4	2	2	2
1	2	3	2	3	3
2	2	3	2	3	3
1	2	4	2	3	3
2	2	4	2	3	3
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN              
(t3, t4, t5)
ON t2.b=t4.b;
a	b	a	b	a	b	a	b
4	2	1	2	3	2	3	1
4	2	2	2	3	2	3	1
4	2	1	2	4	2	3	1
4	2	2	2	4	2	3	1
4	2	1	2	3	2	2	2
4	2	2	2	3	2	2	2
4	2	1	2	4	2	2	2
4	2	2	2	4	2	2	2
4	2	1	2	3	2	3	3
4	2	2	2	3	2	3	3
4	2	1	2	4	2	3	3
4	2	2	2	4	2	3	3
3	3	NULL	NULL	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN              
(t3, t4, t5)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer (incremental, BNL join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4` join `test`.`t5`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) where ((`test`.`t3`.`a` > 1) or isnull(`test`.`t3`.`c`))
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN              
(t3, t4, t5)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
a	b	a	b	a	b	a	b
4	2	2	2	3	2	3	1
4	2	2	2	4	2	3	1
4	2	2	2	3	2	2	2
4	2	2	2	4	2	2	2
4	2	2	2	3	2	3	3
4	2	2	2	4	2	3	3
3	3	NULL	NULL	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN              
(t3, t4, t5)
ON t2.b=t4.b
WHERE (t3.a>1 OR t3.c IS NULL) AND 
(t5.a<3 OR t5.c IS NULL);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4` join `test`.`t5`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) where (((`test`.`t3`.`a` > 1) or isnull(`test`.`t3`.`c`)) and ((`test`.`t5`.`a` < 3) or isnull(`test`.`t5`.`c`)))
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN              
(t3, t4, t5)
ON t2.b=t4.b
WHERE (t3.a>1 OR t3.c IS NULL) AND 
(t5.a<3 OR t5.c IS NULL);
a	b	a	b	a	b	a	b
4	2	2	2	3	2	2	2
4	2	2	2	4	2	2	2
3	3	NULL	NULL	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t6.a,t6.b
FROM t6;
a	b
3	2
6	2
6	1
SELECT t7.a,t7.b
FROM t7;
a	b
1	1
2	2
SELECT t6.a,t6.b,t7.a,t7.b
FROM t6,t7;
a	b	a	b
3	2	1	1
3	2	2	2
6	2	1	1
6	2	2	2
6	1	1	1
6	1	2	2
SELECT t8.a,t8.b
FROM t8;
a	b
0	2
1	2
EXPLAIN EXTENDED
SELECT t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM (t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	100.00	
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer (flat, BNL join)
1	SIMPLE	t8	hash_ALL	NULL	#hash#$hj	5	test.t7.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b` from `test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t7`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t7`.`b` is not null))) where 1
SELECT t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM (t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10;
a	b	a	b	a	b
3	2	2	2	0	2
6	2	2	2	0	2
6	1	2	2	0	2
3	2	2	2	1	2
6	2	2	2	1	2
6	1	2	2	1	2
3	2	1	1	NULL	NULL
6	2	1	1	NULL	NULL
6	1	1	1	NULL	NULL
SELECT t5.a,t5.b
FROM t5;
a	b
3	1
2	2
3	3
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b;
a	b	a	b	a	b	a	b
2	2	3	2	2	2	0	2
2	2	6	2	2	2	0	2
2	2	3	2	2	2	1	2
2	2	6	2	2	2	1	2
3	1	3	2	1	1	NULL	NULL
3	1	6	2	1	1	NULL	NULL
3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b AND
(t8.a < 1 OR t8.c IS NULL);
a	b	a	b	a	b	a	b
2	2	3	2	2	2	0	2
2	2	6	2	2	2	0	2
3	1	3	2	1	1	NULL	NULL
3	1	6	2	1	1	NULL	NULL
3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	1	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b;
a	b	a	b	a	b	a	b	a	b	a	b	a	b
4	2	1	2	3	2	2	2	3	2	2	2	0	2
4	2	1	2	4	2	2	2	3	2	2	2	0	2
4	2	1	2	3	2	2	2	6	2	2	2	0	2
4	2	1	2	4	2	2	2	6	2	2	2	0	2
4	2	1	2	3	2	2	2	3	2	2	2	1	2
4	2	1	2	4	2	2	2	3	2	2	2	1	2
4	2	1	2	3	2	2	2	6	2	2	2	1	2
4	2	1	2	4	2	2	2	6	2	2	2	1	2
4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b
WHERE t2.a > 3 AND
(t6.a < 6 OR t6.c IS NULL);
a	b	a	b	a	b	a	b	a	b	a	b	a	b
4	2	1	2	3	2	2	2	3	2	2	2	0	2
4	2	1	2	4	2	2	2	3	2	2	2	0	2
4	2	1	2	3	2	2	2	3	2	2	2	1	2
4	2	1	2	4	2	2	2	3	2	2	2	1	2
4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b
FROM t1;
a	b
1	3
2	2
3	2
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
1	3	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	3	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	3	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	3	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE (t2.a >= 4 OR t2.c IS NULL);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
1	3	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t0.a,t0.b
FROM t0;
a	b
1	1
1	2
2	2
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)))
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	2	3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
1	2	3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
1	2	3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
1	2	3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
1	2	3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) join `test`.`t9` where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t9`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t4`.`b` = `test`.`t3`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t9`.`b` = `test`.`t8`.`b`) or isnull(`test`.`t8`.`c`)))
SELECT t9.a,t9.b
FROM t9;
a	b
1	1
1	2
3	3
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	2
SELECT t1.a,t1.b
FROM t1;
a	b
1	3
2	2
3	2
SELECT t2.a,t2.b
FROM t2;
a	b
3	3
4	2
5	3
SELECT t3.a,t3.b
FROM t3;
a	b
1	2
2	2
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 
LEFT JOIN              
t3
ON t2.b=t3.b;
a	b	a	b
4	2	1	2
4	2	2	2
3	3	NULL	NULL
5	3	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b
FROM t1, t2 
LEFT JOIN              
t3
ON t2.b=t3.b
WHERE t1.a <= 2;
a	b	a	b	a	b
1	3	4	2	1	2
2	2	4	2	1	2
1	3	4	2	2	2
2	2	4	2	2	2
1	3	3	3	NULL	NULL
2	2	3	3	NULL	NULL
1	3	5	3	NULL	NULL
2	2	5	3	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b
FROM t1, t3 
RIGHT JOIN              
t2
ON t2.b=t3.b
WHERE t1.a <= 2;
a	b	a	b	a	b
1	3	4	2	1	2
2	2	4	2	1	2
1	3	4	2	2	2
2	2	4	2	2	2
1	3	3	3	NULL	NULL
2	2	3	3	NULL	NULL
1	3	5	3	NULL	NULL
2	2	5	3	NULL	NULL
SELECT t3.a,t3.b,t4.a,t4.b
FROM t3,t4;
a	b	a	b
1	2	3	2
2	2	3	2
1	2	4	2
2	2	4	2
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2 
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	1	2	4	2
3	3	NULL	NULL	NULL	NULL
5	3	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, t2 
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
a	b	a	b	a	b	a	b
1	3	4	2	1	2	3	2
2	2	4	2	1	2	3	2
1	3	4	2	1	2	4	2
2	2	4	2	1	2	4	2
1	3	3	3	NULL	NULL	NULL	NULL
2	2	3	3	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL
2	2	5	3	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, (t3, t4) 
RIGHT JOIN              
t2
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
a	b	a	b	a	b	a	b
1	3	4	2	1	2	3	2
2	2	4	2	1	2	3	2
1	3	4	2	1	2	4	2
2	2	4	2	1	2	4	2
1	3	3	3	NULL	NULL	NULL	NULL
2	2	3	3	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL
2	2	5	3	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, (t3, t4)
RIGHT JOIN              
t2
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
a	b	a	b	a	b	a	b
1	3	4	2	1	2	3	2
2	2	4	2	1	2	3	2
1	3	4	2	1	2	4	2
2	2	4	2	1	2	4	2
1	3	3	3	NULL	NULL	NULL	NULL
2	2	3	3	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL
2	2	5	3	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, (t3, t4)
RIGHT JOIN
t2
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer (flat, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t1` join `test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) where (`test`.`t1`.`a` <= 2)
INSERT INTO t2 VALUES  (-1,9,0), (-3,10,0), (-2,8,0), (-4,11,0), (-5,15,0);
CREATE INDEX idx_b ON t2(b);
EXPLAIN EXTENDED
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM (t3,t4)
LEFT JOIN              
(t1,t2)
ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b AND t2.a>0;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
1	SIMPLE	t2	ref	idx_b	idx_b	5	test.t3.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer (incremental, BNL join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t3` join `test`.`t4` left join (`test`.`t1` join `test`.`t2`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t3`.`b`) and (`test`.`t2`.`b` = `test`.`t3`.`b`) and (`test`.`t2`.`a` > 0) and (`test`.`t3`.`b` is not null))) where 1
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM (t3,t4)
LEFT JOIN              
(t1,t2)
ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b AND t2.a>0;
a	b	a	b	a	b
4	2	1	2	3	2
4	2	1	2	4	2
4	2	1	2	3	2
4	2	1	2	4	2
4	2	1	2	3	2
4	2	1	2	4	2
NULL	NULL	2	2	3	2
NULL	NULL	2	2	4	2
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b AND t2.a>0,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`a` > 0) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) join `test`.`t9` where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t9`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t3`.`b` = `test`.`t4`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t9`.`b` = `test`.`t8`.`b`) or isnull(`test`.`t8`.`c`)))
INSERT INTO t4 VALUES (-3,12,0), (-4,13,0), (-1,11,0), (-3,11,0), (-5,15,0);
INSERT INTO t5 VALUES (-3,11,0), (-2,12,0), (-3,13,0), (-4,12,0);
CREATE INDEX idx_b ON t4(b);
CREATE INDEX idx_b ON t5(b);
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b AND t2.a>0 AND t4.a>0,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b AND t5.a>0 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	7	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`a` > 0) and (`test`.`t4`.`a` > 0) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`a` > 0) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) join `test`.`t9` where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t9`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t4`.`b` = `test`.`t3`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t8`.`b` = `test`.`t9`.`b`) or isnull(`test`.`t8`.`c`)))
INSERT INTO t8 VALUES (-3,12,0), (-1,14,0), (-5,15,0), (-1,11,0), (-4,13,0);
CREATE INDEX idx_b ON t8(b);
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b AND t2.a>0 AND t4.a>0,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10 AND t8.a>=0
)
ON t6.b >= 2 AND t5.b=t7.b AND t5.a>0
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
1	SIMPLE	t1	hash_ALL	NULL	#hash#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	7	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t8	ref	idx_b	idx_b	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`a` > 0) and (`test`.`t4`.`a` > 0) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t8`.`a` >= 0) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`a` > 0) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) join `test`.`t9` where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t9`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t4`.`b` = `test`.`t3`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t8`.`b` = `test`.`t9`.`b`) or isnull(`test`.`t8`.`c`)))
INSERT INTO t1 VALUES (-1,133,0), (-2,12,0), (-3,11,0), (-5,15,0);
CREATE INDEX idx_b ON t1(b);
CREATE INDEX idx_a ON t0(a);
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2) AND t1.a>0,
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t0	ref	idx_a	idx_a	5	const	1	100.00	Using where
1	SIMPLE	t1	ref	idx_b	idx_b	5	test.t0.b	2	100.00	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	7	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t7	hash_ALL	NULL	#hash#$hj	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BNLH join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	ref	idx_b	idx_b	5	test.t5.b	2	100.00	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t3`.`a` = 1) and (`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` is not null))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10) and (`test`.`t5`.`b` is not null)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2) and (`test`.`t5`.`b` is not null)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2) and (`test`.`t1`.`a` > 0))) join `test`.`t9` where ((`test`.`t0`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t9`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t4`.`b` = `test`.`t3`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t8`.`b` = `test`.`t9`.`b`) or isnull(`test`.`t8`.`c`)))
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2) AND t1.a>0,
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	2
SELECT t2.a,t2.b
FROM t2;
a	b
3	3
4	2
5	3
-1	9
-3	10
-2	8
-4	11
-5	15
SELECT t3.a,t3.b
FROM t3;
a	b
1	2
2	2
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a IS NULL);
a	b	a	b
4	2	1	2
4	2	2	2
5	3	NULL	NULL
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 LEFT JOIN (t3) ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a IS NULL);
a	b	a	b
4	2	1	2
4	2	2	2
5	3	NULL	NULL
ALTER TABLE t3
CHANGE COLUMN a a1 int,
CHANGE COLUMN c c1 int;
SELECT t2.a,t2.b,t3.a1,t3.b
FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a1 IS NULL);
a	b	a1	b
4	2	1	2
4	2	2	2
5	3	NULL	NULL
SELECT t2.a,t2.b,t3.a1,t3.b
FROM t2 NATURAL LEFT JOIN t3
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a1 IS NULL);
a	b	a1	b
4	2	1	2
4	2	2	2
5	3	NULL	NULL
DROP TABLE t0,t1,t2,t3,t4,t5,t6,t7,t8,t9;
CREATE TABLE t1 (a int);
CREATE TABLE t2 (a int);
CREATE TABLE t3 (a int);
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
INSERT INTO t3 VALUES (2);
INSERT INTO t1 VALUES (2);
SELECT * FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.a=t3.a) ON t1.a=t3.a;
a	a	a
2	2	2
1	NULL	NULL
SELECT * FROM t1 LEFT JOIN t2 LEFT JOIN t3 ON t2.a=t3.a ON t1.a=t3.a;
a	a	a
2	2	2
1	NULL	NULL
DELETE FROM t1 WHERE a=2;
SELECT * FROM t1 LEFT JOIN t2 LEFT JOIN t3 ON t2.a=t3.a ON t1.a=t3.a;
a	a	a
1	NULL	NULL
DELETE FROM t2;
SELECT * FROM t1 LEFT JOIN t2 LEFT JOIN t3 ON t2.a=t3.a ON t1.a=t3.a;
a	a	a
1	NULL	NULL
DROP TABLE t1,t2,t3;
CREATE TABLE t1(a int, key (a));
CREATE TABLE t2(b int, key (b));
CREATE TABLE t3(c int, key (c));
INSERT INTO t1 VALUES (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
(10), (11), (12), (13), (14), (15), (16), (17), (18), (19);
INSERT INTO t2 VALUES (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
(10), (11), (12), (13), (14), (15), (16), (17), (18), (19);
INSERT INTO t3 VALUES (0), (1), (2), (3), (4), (5);
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON c < 3 and b = c;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
1	SIMPLE	t3	index	c	c	5	NULL	6	Using where; Using index
1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
1	SIMPLE	t3	index	c	c	5	NULL	6	Using where; Using index
1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
a	b	c
NULL	0	0
NULL	1	1
NULL	2	2
0	0	0
0	1	1
0	2	2
1	0	0
1	1	1
1	2	2
2	0	0
2	1	1
2	2	2
3	0	0
3	1	1
3	2	2
4	0	0
4	1	1
4	2	2
5	0	0
5	1	1
5	2	2
6	0	0
6	1	1
6	2	2
7	0	0
7	1	1
7	2	2
8	0	0
8	1	1
8	2	2
9	0	0
9	1	1
9	2	2
10	0	0
10	1	1
10	2	2
11	0	0
11	1	1
11	2	2
12	0	0
12	1	1
12	2	2
13	0	0
13	1	1
13	2	2
14	0	0
14	1	1
14	2	2
15	0	0
15	1	1
15	2	2
16	0	0
16	1	1
16	2	2
17	0	0
17	1	1
17	2	2
18	0	0
18	1	1
18	2	2
19	0	0
19	1	1
19	2	2
DELETE FROM t3;
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
1	SIMPLE	t3	index	c	c	5	NULL	0	Using where; Using index
1	SIMPLE	t2	ref	b	b	5	test.t3.c	2	Using index
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
a	b	c
NULL	NULL	NULL
0	NULL	NULL
1	NULL	NULL
2	NULL	NULL
3	NULL	NULL
4	NULL	NULL
5	NULL	NULL
6	NULL	NULL
7	NULL	NULL
8	NULL	NULL
9	NULL	NULL
10	NULL	NULL
11	NULL	NULL
12	NULL	NULL
13	NULL	NULL
14	NULL	NULL
15	NULL	NULL
16	NULL	NULL
17	NULL	NULL
18	NULL	NULL
19	NULL	NULL
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (c11 int);
CREATE TABLE t2 (c21 int);
CREATE TABLE t3 (c31 int);
INSERT INTO t1 VALUES (4), (5);
SELECT * FROM t1 LEFT JOIN t2 ON c11=c21;
c11	c21
4	NULL
5	NULL
EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON c11=c21;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	system	NULL	NULL	NULL	NULL	0	const row not found
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
SELECT * FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON c21=c31) ON c11=c21;
c11	c21	c31
4	NULL	NULL
5	NULL	NULL
EXPLAIN SELECT * FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON c21=c31) ON c11=c21;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t2	hash_ALL	NULL	#hash#$hj	5	test.t1.c11	0	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	0	Using where; Using join buffer (incremental, BNL join)
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (goods int(12) NOT NULL, price varchar(128) NOT NULL);
INSERT INTO t1 VALUES (23, 2340), (26, 9900);
CREATE TABLE t2 (goods int(12), name varchar(50), shop char(2));
INSERT INTO t2 VALUES (23, 'as300', 'fr'), (26, 'as600', 'fr');
create table t3 (groupid int(12) NOT NULL, goodsid int(12) NOT NULL);
INSERT INTO t3 VALUES (3,23), (6,26);
CREATE TABLE t4 (groupid int(12));
INSERT INTO t4 VALUES (1), (2), (3), (4), (5), (6);
SELECT * FROM
(SELECT DISTINCT gl.groupid, gp.price
FROM t4 gl 
LEFT JOIN
(t3 g INNER JOIN t2 p ON g.goodsid = p.goods 
INNER JOIN t1 gp ON p.goods = gp.goods)
ON gl.groupid = g.groupid and p.shop = 'fr') t;
groupid	price
3	2340
6	9900
1	NULL
2	NULL
4	NULL
5	NULL
CREATE VIEW v1 AS
SELECT g.groupid groupid, p.goods goods,  
p.name name, p.shop shop, 
gp.price price
FROM t3 g INNER JOIN t2 p ON g.goodsid = p.goods
INNER JOIN t1 gp on p.goods = gp.goods;
CREATE VIEW v2 AS
SELECT DISTINCT g.groupid, fr.price
FROM t4 g
LEFT JOIN
v1 fr on g.groupid = fr.groupid and fr.shop = 'fr';
SELECT * FROM v2;
groupid	price
3	2340
6	9900
1	NULL
2	NULL
4	NULL
5	NULL
SELECT * FROM 
(SELECT DISTINCT g.groupid, fr.price
FROM t4 g
LEFT JOIN
v1 fr on g.groupid = fr.groupid and fr.shop = 'fr') t;
groupid	price
3	2340
6	9900
1	NULL
2	NULL
4	NULL
5	NULL
DROP VIEW v1,v2;
DROP TABLE t1,t2,t3,t4;
CREATE TABLE t1(a int);
CREATE TABLE t2(b int);
CREATE TABLE t3(c int, d int);
CREATE TABLE t4(d int);
CREATE TABLE t5(e int, f int);
CREATE TABLE t6(f int);
CREATE VIEW v1 AS 
SELECT e FROM t5 JOIN t6 ON t5.e=t6.f;
CREATE VIEW v2 AS 
SELECT e FROM t5 NATURAL JOIN t6;
SELECT t1.a FROM t1 JOIN t2 ON a=b JOIN t3 ON a=c JOIN t4 USING(d);
a
SELECT t1.x FROM t1 JOIN t2 ON a=b JOIN t3 ON a=c JOIN t4 USING(d);
ERROR 42S22: Unknown column 't1.x' in 'field list'
SELECT t1.a FROM t1 JOIN t2 ON a=b JOIN t3 ON a=c NATURAL JOIN t4;
a
SELECT t1.x FROM t1 JOIN t2 ON a=b JOIN t3 ON a=c NATURAL JOIN t4;
ERROR 42S22: Unknown column 't1.x' in 'field list'
SELECT v1.e FROM v1 JOIN t2 ON e=b JOIN t3 ON e=c JOIN t4 USING(d);
e
SELECT v1.x FROM v1 JOIN t2 ON e=b JOIN t3 ON e=c JOIN t4 USING(d);
ERROR 42S22: Unknown column 'v1.x' in 'field list'
SELECT v2.e FROM v2 JOIN t2 ON e=b JOIN t3 ON e=c JOIN t4 USING(d);
e
SELECT v2.x FROM v2 JOIN t2 ON e=b JOIN t3 ON e=c JOIN t4 USING(d);
ERROR 42S22: Unknown column 'v2.x' in 'field list'
DROP VIEW v1, v2;
DROP TABLE t1, t2, t3, t4, t5, t6;
create table t1 (id1 int(11) not null);
insert into t1 values (1),(2);
create table t2 (id2 int(11) not null);
insert into t2 values (1),(2),(3),(4);
create table t3 (id3 char(16) not null);
insert into t3 values ('100');
create table t4 (id2 int(11) not null, id3 char(16));
create table t5 (id1 int(11) not null, key (id1));
insert into t5 values (1),(2),(1);
create view v1 as
select t4.id3 from t4 join t2 on t4.id2 = t2.id2;
select t1.id1 from t1 inner join (t3 left join v1 on t3.id3 = v1.id3);
id1
1
2
drop view v1;
drop table t1, t2, t3, t4, t5;
create table t0 (a int);
insert into t0 values (0),(1),(2),(3);
create table t1(a int);
insert into t1 select A.a + 10*(B.a) from t0 A, t0 B;
create table t2 (a int, b int);
insert into t2 values (1,1), (2,2), (3,3);
create table t3(a int, b int, filler char(200), key(a));
insert into t3 select a,a,'filler' from t1;
insert into t3 select a,a,'filler' from t1;
create table t4 like t3;
insert into t4 select * from t3;
insert into t4 select * from t3;
create table t5 like t4;
insert into t5 select * from t4;
insert into t5 select * from t4;
create table t6 like t5;
insert into t6 select * from t5;
insert into t6 select * from t5;
create table t7 like t6;
insert into t7 select * from t6;
insert into t7 select * from t6;
explain select * from t4 join 
t2 left join (t3 join t5 on t5.a=t3.b) on t3.a=t2.b where t4.a<=>t3.b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	X	
1	SIMPLE	t3	ref	a	a	5	test.t2.b	X	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ref	a	a	5	test.t3.b	X	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t4	ref	a	a	5	test.t3.b	X	Using index condition(BKA); Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
explain select * from (t4 join t6 on t6.a=t4.b) right join t3 on t4.a=t3.b
join t2 left join (t5 join t7 on t7.a=t5.b) on t5.a=t2.b where t3.a<=>t2.b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	X	
1	SIMPLE	t3	ref	a	a	5	test.t2.b	X	Using index condition(BKA); Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t4	ref	a	a	5	test.t3.b	X	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t6	ref	a	a	5	test.t4.b	X	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ref	a	a	5	test.t2.b	X	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t7	ref	a	a	5	test.t5.b	X	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
explain select * from t2 left join
(t3 left join (t4 join t6 on t6.a=t4.b) on t4.a=t3.b 
join t5 on t5.a=t3.b) on t3.a=t2.b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	X	
1	SIMPLE	t3	ref	a	a	5	test.t2.b	X	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t5	ref	a	a	5	test.t3.b	X	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t4	ref	a	a	5	test.t5.a	X	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t6	ref	a	a	5	test.t4.b	X	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
drop table t0, t1, t2, t3, t4, t5, t6, t7;
create table t1 (a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t2 (a int, filler char(100), key(a));
insert into t2 select A.a + 10*B.a, '' from t1 A, t1 B;
create table t3 like t2;
insert into t3 select * from t2;
explain select * from t1 left join 
(t2 left join t3 on (t2.a = t3.a)) 
on (t1.a = t2.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	
1	SIMPLE	t2	ref	a	a	5	test.t1.a	1	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t3	ref	a	a	5	test.t1.a	1	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
drop table t1, t2, t3;
CREATE TABLE t1 (id int NOT NULL PRIMARY KEY, type varchar(10));
CREATE TABLE t2 (pid int NOT NULL PRIMARY KEY, type varchar(10));
CREATE TABLE t3 (cid int NOT NULL PRIMARY KEY,
id int NOT NULL,
pid int NOT NULL);
INSERT INTO t1 VALUES (1, 'A'), (3, 'C');
INSERT INTO t2 VALUES (1, 'A'), (3, 'C');
INSERT INTO t3 VALUES (1, 1, 1), (3, 3, 3);
SELECT * FROM t1 p LEFT JOIN (t3 JOIN t1)
ON (t1.id=t3.id AND t1.type='B' AND p.id=t3.id)
LEFT JOIN t2 ON (t3.pid=t2.pid)
WHERE p.id=1;
id	type	cid	id	pid	id	type	pid	type
1	A	NULL	NULL	NULL	NULL	NULL	NULL	NULL
CREATE VIEW v1 AS
SELECT t3.* FROM t3 JOIN t1 ON t1.id=t3.id AND t1.type='B';
SELECT * FROM t1 p LEFT JOIN v1 ON p.id=v1.id
LEFT JOIN t2 ON v1.pid=t2.pid
WHERE p.id=1;
id	type	cid	id	pid	pid	type
1	A	NULL	NULL	NULL	NULL	NULL
DROP VIEW v1;
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (id1 int PRIMARY KEY, id2 int);
CREATE TABLE t2 (id1 int PRIMARY KEY, id2 int);
CREATE TABLE t3 (id1 int PRIMARY KEY, id2 int);
CREATE TABLE t4 (id1 int PRIMARY KEY, id2 int);
CREATE TABLE t5 (id1 int PRIMARY KEY, id2 int);
SELECT t1.id1 AS id, t5.id1 AS ngroupbynsa
FROM t1 INNER JOIN t2 ON t2.id2 = t1.id1
LEFT OUTER JOIN
(t3 INNER JOIN t4 ON t4.id1 = t3.id2 INNER JOIN t5 ON t4.id2 = t5.id1)
ON t3.id2 IS NOT NULL
WHERE t1.id1=2;
id	ngroupbynsa
PREPARE stmt FROM
"SELECT t1.id1 AS id, t5.id1 AS ngroupbynsa
  FROM t1 INNER JOIN t2 ON t2.id2 = t1.id1
       LEFT OUTER JOIN
       (t3 INNER JOIN t4 ON t4.id1 = t3.id2 INNER JOIN t5 ON t4.id2 = t5.id1)
       ON t3.id2 IS NOT NULL
    WHERE t1.id1=2";
EXECUTE stmt;
id	ngroupbynsa
EXECUTE stmt;
id	ngroupbynsa
EXECUTE stmt;
id	ngroupbynsa
EXECUTE stmt;
id	ngroupbynsa
INSERT INTO t1 VALUES (1,1), (2,1), (3,2);
INSERT INTO t2 VALUES (2,1), (3,2), (4,3);
INSERT INTO t3 VALUES (1,1), (3,2), (2,NULL);
INSERT INTO t4 VALUES (1,1), (2,1), (3,3);
INSERT INTO t5 VALUES (1,1), (2,2), (3,3), (4,3);
EXECUTE stmt;
id	ngroupbynsa
2	1
2	1
EXECUTE stmt;
id	ngroupbynsa
2	1
2	1
EXECUTE stmt;
id	ngroupbynsa
2	1
2	1
EXECUTE stmt;
id	ngroupbynsa
2	1
2	1
SELECT t1.id1 AS id, t5.id1 AS ngroupbynsa
FROM t1 INNER JOIN t2 ON t2.id2 = t1.id1
LEFT OUTER JOIN
(t3 INNER JOIN t4 ON t4.id1 = t3.id2 INNER JOIN t5 ON t4.id2 = t5.id1)
ON t3.id2 IS NOT NULL
WHERE t1.id1=2;
id	ngroupbynsa
2	1
2	1
DROP TABLE t1,t2,t3,t4,t5;
CREATE TABLE t1 (
id int NOT NULL PRIMARY KEY,
ct int DEFAULT NULL,
pc int DEFAULT NULL,
INDEX idx_ct (ct),
INDEX idx_pc (pc)
);
INSERT INTO t1 VALUES  
(1,NULL,NULL),(2,NULL,NULL),(3,NULL,NULL),(4,NULL,NULL),(5,NULL,NULL);
CREATE TABLE t2 (
id int NOT NULL PRIMARY KEY,
sr int NOT NULL,
nm varchar(255) NOT NULL,
INDEX idx_sr (sr)
);
INSERT INTO t2 VALUES
(2441905,4308,'LesAbymes'),(2441906,4308,'Anse-Bertrand');
CREATE TABLE t3 (
id int NOT NULL PRIMARY KEY,
ct int NOT NULL,
ln int NOT NULL,
INDEX idx_ct (ct),
INDEX idx_ln (ln)
);
CREATE TABLE t4 (
id int NOT NULL PRIMARY KEY,
nm varchar(255) NOT NULL
);
INSERT INTO t4 VALUES (4308,'Guadeloupe'),(4309,'Martinique');
SELECT t1.*
FROM t1 LEFT JOIN
(t2 LEFT JOIN t3 ON t3.ct=t2.id AND t3.ln='5') ON t1.ct=t2.id
WHERE t1.id='5';
id	ct	pc
5	NULL	NULL
SELECT t1.*, t4.nm
FROM t1 LEFT JOIN
(t2 LEFT JOIN t3 ON t3.ct=t2.id AND t3.ln='5') ON t1.ct=t2.id
LEFT JOIN t4 ON t2.sr=t4.id
WHERE t1.id='5';
id	ct	pc	nm
5	NULL	NULL	NULL
DROP TABLE t1,t2,t3,t4;
CREATE TABLE t1 (a INT, b INT);
CREATE TABLE t2 (a INT);
CREATE TABLE t3 (a INT, c INT);
CREATE TABLE t4 (a INT, c INT);
CREATE TABLE t5 (a INT, c INT);
SELECT b FROM t1 JOIN (t2 LEFT JOIN t3 USING (a) LEFT JOIN t4 USING (a)
LEFT JOIN t5 USING (a)) USING (a);
b
SELECT c FROM t1 JOIN (t2 LEFT JOIN t3 USING (a) LEFT JOIN t4 USING (a)
LEFT JOIN t5 USING (a)) USING (a);
ERROR 23000: Column 'c' in field list is ambiguous
SELECT b FROM t1 JOIN (t2 JOIN t3 USING (a) JOIN t4 USING (a)
JOIN t5 USING (a)) USING (a);
b
SELECT c FROM t1 JOIN (t2 JOIN t3 USING (a) JOIN t4 USING (a)
JOIN t5 USING (a)) USING (a);
ERROR 23000: Column 'c' in field list is ambiguous
DROP TABLE t1,t2,t3,t4,t5;
CREATE TABLE t1 (a INT, b INT);
CREATE TABLE t2 (a INT, b INT);
CREATE TABLE t3 (a INT, b INT);
INSERT INTO t1 VALUES (1,1);
INSERT INTO t2 VALUES (1,1);
INSERT INTO t3 VALUES (1,1);
SELECT * FROM t1 JOIN (t2 JOIN t3 USING (b)) USING (a);
ERROR 23000: Column 'a' in from clause is ambiguous
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (
carrier char(2) default NULL,
id int NOT NULL auto_increment PRIMARY KEY
);
INSERT INTO t1 VALUES
('CO',235371754),('CO',235376554),('CO',235376884),('CO',235377874),
('CO',231060394),('CO',231059224),('CO',231059314),('CO',231060484),
('CO',231060274),('CO',231060124),('CO',231060244),('CO',231058594),
('CO',231058924),('CO',231058504),('CO',231059344),('CO',231060424),
('CO',231059554),('CO',231060304),('CO',231059644),('CO',231059464),
('CO',231059764),('CO',231058294),('CO',231058624),('CO',231058864),
('CO',231059374),('CO',231059584),('CO',231059734),('CO',231059014),
('CO',231059854),('CO',231059494),('CO',231059794),('CO',231058534),
('CO',231058324),('CO',231058684),('CO',231059524),('CO',231059974);
CREATE TABLE t2 (
scan_date date default NULL,
package_id int default NULL,
INDEX scan_date(scan_date),
INDEX package_id(package_id)
);
INSERT INTO t2 VALUES
('2008-12-29',231062944),('2008-12-29',231065764),('2008-12-29',231066124),
('2008-12-29',231060094),('2008-12-29',231061054),('2008-12-29',231065644),
('2008-12-29',231064384),('2008-12-29',231064444),('2008-12-29',231073774),
('2008-12-29',231058594),('2008-12-29',231059374),('2008-12-29',231066004),
('2008-12-29',231068494),('2008-12-29',231070174),('2008-12-29',231071884),
('2008-12-29',231063274),('2008-12-29',231063754),('2008-12-29',231064144),
('2008-12-29',231069424),('2008-12-29',231073714),('2008-12-29',231058414),
('2008-12-29',231060994),('2008-12-29',231069154),('2008-12-29',231068614),
('2008-12-29',231071464),('2008-12-29',231074014),('2008-12-29',231059614),
('2008-12-29',231059074),('2008-12-29',231059464),('2008-12-29',231069094),
('2008-12-29',231067294),('2008-12-29',231070144),('2008-12-29',231073804),
('2008-12-29',231072634),('2008-12-29',231058294),('2008-12-29',231065344),
('2008-12-29',231066094),('2008-12-29',231069034),('2008-12-29',231058594),
('2008-12-29',231059854),('2008-12-29',231059884),('2008-12-29',231059914),
('2008-12-29',231063664),('2008-12-29',231063814),('2008-12-29',231063904);
CREATE TABLE t3 (
package_id int default NULL,
INDEX package_id(package_id)
);
INSERT INTO t3 VALUES
(231058294),(231058324),(231058354),(231058384),(231058414),(231058444),
(231058474),(231058504),(231058534),(231058564),(231058594),(231058624),
(231058684),(231058744),(231058804),(231058864),(231058924),(231058954),
(231059014),(231059074),(231059104),(231059134),(231059164),(231059194),
(231059224),(231059254),(231059284),(231059314),(231059344),(231059374),
(231059404),(231059434),(231059464),(231059494),(231059524),(231059554),
(231059584),(231059614),(231059644),(231059674),(231059704),(231059734),
(231059764),(231059794),(231059824),(231059854),(231059884),(231059914),
(231059944),(231059974),(231060004),(231060034),(231060064),(231060094),
(231060124),(231060154),(231060184),(231060214),(231060244),(231060274),
(231060304),(231060334),(231060364),(231060394),(231060424),(231060454),
(231060484),(231060514),(231060544),(231060574),(231060604),(231060634),
(231060664),(231060694),(231060724),(231060754),(231060784),(231060814),
(231060844),(231060874),(231060904),(231060934),(231060964),(231060994),
(231061024),(231061054),(231061084),(231061144),(231061174),(231061204),
(231061234),(231061294),(231061354),(231061384),(231061414),(231061474),
(231061564),(231061594),(231061624),(231061684),(231061714),(231061774),
(231061804),(231061894),(231061984),(231062074),(231062134),(231062224),
(231062254),(231062314),(231062374),(231062434),(231062494),(231062554),
(231062584),(231062614),(231062644),(231062704),(231062734),(231062794),
(231062854),(231062884),(231062944),(231063004),(231063034),(231063064),
(231063124),(231063154),(231063184),(231063214),(231063274),(231063334),
(231063394),(231063424),(231063454),(231063514),(231063574),(231063664);
CREATE TABLE t4 (
carrier char(2) NOT NULL default '' PRIMARY KEY,
id int(11) default NULL,
INDEX id(id)
);
INSERT INTO t4 VALUES
('99',6),('SK',456),('UA',486),('AI',1081),('OS',1111),('VS',1510);
CREATE TABLE t5 (
carrier_id int default NULL,
INDEX carrier_id(carrier_id)
);
INSERT INTO t5 VALUES
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),
(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(6),(456),(456),(456),
(456),(456),(456),(456),(456),(456),(456),(456),(456),(456),(456),(456),
(456),(486),(1081),(1111),(1111),(1111),(1111),(1510);
SELECT COUNT(*) 
FROM((t2 JOIN t1 ON t2.package_id = t1.id) 
JOIN t3 ON t3.package_id = t1.id);
COUNT(*)
6
EXPLAIN
SELECT COUNT(*) 
FROM ((t2 JOIN t1 ON t2.package_id = t1.id) 
JOIN t3 ON t3.package_id = t1.id)
LEFT JOIN 
(t5 JOIN t4 ON t5.carrier_id = t4.id)
ON t4.carrier = t1.carrier;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	package_id	package_id	5	NULL	45	Using where; Using index
1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.package_id	1	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t4	eq_ref	PRIMARY,id	PRIMARY	2	test.t1.carrier	1	Using where
1	SIMPLE	t5	ref	carrier_id	carrier_id	5	test.t4.id	22	Using index
1	SIMPLE	t3	ref	package_id	package_id	5	test.t2.package_id	1	Using index
SELECT COUNT(*) 
FROM ((t2 JOIN t1 ON t2.package_id = t1.id) 
JOIN t3 ON t3.package_id = t1.id)
LEFT JOIN 
(t5 JOIN t4 ON t5.carrier_id = t4.id)
ON t4.carrier = t1.carrier;
COUNT(*)
6
DROP TABLE t1,t2,t3,t4,t5;
CREATE TABLE t1 (
pk int NOT NULL AUTO_INCREMENT PRIMARY KEY,
a int DEFAULT NULL,
KEY idx(a)
);
CREATE TABLE t2 (
pk int  NOT NULL AUTO_INCREMENT PRIMARY KEY,
a int DEFAULT NULL,
KEY idx(a)
);
CREATE TABLE t3 (
pk int NOT NULL AUTO_INCREMENT PRIMARY KEY,
a int DEFAULT NULL,
KEY idx(a)
);
INSERT INTO t1 VALUES 
(1,2), (2,7), (3,5), (4,7), (5,5), (6,NULL), (7,NULL), (8,9);
INSERT INTO t2 VALUES 
(1,NULL), (4,2), (5,2), (3,4), (2,8);
INSERT INTO t3 VALUES
(1,9), (2,2), (3,5), (4,2), (5,7), (6,0), (7,5);
SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a;
pk	a	pk	a	pk	a
1	2	4	2	2	2
1	2	5	2	2	2
1	2	4	2	4	2
1	2	5	2	4	2
2	7	NULL	NULL	NULL	NULL
3	5	NULL	NULL	NULL	NULL
4	7	NULL	NULL	NULL	NULL
5	5	NULL	NULL	NULL	NULL
6	NULL	NULL	NULL	NULL	NULL
7	NULL	NULL	NULL	NULL	NULL
8	9	NULL	NULL	NULL	NULL
SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a
WHERE t2.pk IS NULL;
pk	a	pk	a	pk	a
2	7	NULL	NULL	NULL	NULL
3	5	NULL	NULL	NULL	NULL
4	7	NULL	NULL	NULL	NULL
5	5	NULL	NULL	NULL	NULL
6	NULL	NULL	NULL	NULL	NULL
7	NULL	NULL	NULL	NULL	NULL
8	9	NULL	NULL	NULL	NULL
SELECT t1.pk, t1.a, t2.pk, t2.a,t3.pk, t3.a 
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t3.a=t2.a) ON t2.a=t1.a
WHERE t3.pk IS NULL;
pk	a	pk	a	pk	a
2	7	NULL	NULL	NULL	NULL
3	5	NULL	NULL	NULL	NULL
4	7	NULL	NULL	NULL	NULL
5	5	NULL	NULL	NULL	NULL
6	NULL	NULL	NULL	NULL	NULL
7	NULL	NULL	NULL	NULL	NULL
8	9	NULL	NULL	NULL	NULL
DROP TABLE t1, t2, t3;
CREATE TABLE t1 (a int NOT NULL );
INSERT INTO t1 VALUES (9), (9);
CREATE TABLE t2 (a int NOT NULL );
INSERT INTO t2 VALUES (9);
CREATE TABLE t3 (a int NOT NULL, b int);
INSERT INTO t3 VALUES (19,9);
CREATE TABLE t4 (b int) ;
SELECT * FROM t1 LEFT JOIN
((t2 LEFT JOIN t3 ON t2.a=t3.b) LEFT JOIN t4 ON t3.a=t4.b)
ON t1.a=t2.a;
a	a	a	b	b
9	9	19	9	NULL
9	9	19	9	NULL
SELECT * FROM t1 LEFT JOIN
((t2 LEFT JOIN t3 ON t2.a=t3.b) LEFT JOIN t4 ON t3.a=t4.b)
ON t1.a=t2.a
WHERE t3.a IS NULL;
a	a	a	b	b
EXPLAIN EXTENDED
SELECT * FROM t1 LEFT JOIN
((t2 LEFT JOIN t3 ON t2.a=t3.b) LEFT JOIN t4 ON t3.a=t4.b)
ON t1.a=t2.a
WHERE t3.a IS NULL;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
1	SIMPLE	t2	hash_ALL	NULL	#hash#$hj	4	test.t1.a	1	100.00	Using where; Using join buffer (flat, BNLH join)
1	SIMPLE	t3	hash_ALL	NULL	#hash#$hj	5	test.t1.a	1	100.00	Using where; Not exists; Using join buffer (incremental, BNLH join)
1	SIMPLE	t4	hash_ALL	NULL	#hash#$hj	5	test.t3.a	0	0.00	Using where; Using join buffer (incremental, BNLH join)
Warnings:
Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`b` AS `b` from `test`.`t1` left join (`test`.`t2` left join `test`.`t3` on((`test`.`t3`.`b` = `test`.`t1`.`a`)) left join `test`.`t4` on(((`test`.`t4`.`b` = `test`.`t3`.`a`) and (`test`.`t3`.`a` is not null)))) on((`test`.`t2`.`a` = `test`.`t1`.`a`)) where isnull(`test`.`t3`.`a`)
DROP TABLE t1,t2,t3,t4;
SET optimizer_switch=@save_optimizer_switch;
End of 5.0 tests
#
# MDEV-621: LP:693329 - Assertion `!is_interleave_error' failed on low optimizer_search_depth
#
set @tmp_mdev621= @@optimizer_search_depth;
SET SESSION optimizer_search_depth = 4;
CREATE TABLE t1 (f1 int,f2 int,f3 int,f4 int) ;
INSERT IGNORE INTO t1 VALUES (0,0,2,0),(NULL,0,2,0);
CREATE TABLE t2 (f1 int) ;
CREATE TABLE t3 (f3 int,PRIMARY KEY (f3)) ;
CREATE TABLE t4 (f5 int) ;
CREATE TABLE t5 (f2 int) ;
SELECT alias2.f4  FROM t1  AS alias1
LEFT    JOIN t1  AS alias2
LEFT  JOIN t2  AS alias3
LEFT  JOIN t3  AS alias4  ON alias3.f1 = alias4.f3
ON alias2.f1
LEFT    JOIN t4  AS alias5
JOIN t5  ON alias5.f5
ON alias2.f3  ON alias1.f2;
f4
NULL
NULL
DROP TABLE t1,t2,t3,t4,t5;
set optimizer_search_depth= @tmp_mdev621;
CREATE TABLE t5 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
CREATE TABLE t6 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
CREATE TABLE t7 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
CREATE TABLE t8 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
INSERT INTO t5 VALUES (1,1,0), (2,2,0), (3,3,0);
INSERT INTO t6 VALUES (1,2,0), (3,2,0), (6,1,0);
INSERT INTO t7 VALUES (1,1,0), (2,2,0);
INSERT INTO t8 VALUES (0,2,0), (1,2,0);
INSERT INTO t6 VALUES (-1,12,0), (-3,13,0), (-6,11,0), (-4,14,0);
INSERT INTO t7 VALUES (-1,11,0), (-2,12,0), (-3,13,0), (-4,14,0), (-5,15,0);
INSERT INTO t8 VALUES (-3,13,0), (-1,12,0), (-2,14,0), (-5,15,0), (-4,16,0);
EXPLAIN
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10 
)
ON t6.b >= 2 AND t5.b=t7.b AND
(t8.a > 0 OR t8.c IS NULL) AND t6.a>0 AND t7.a>0;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	
1	SIMPLE	t7	ref	PRIMARY,b_i	b_i	5	test.t5.b	2	Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t6	ALL	PRIMARY,b_i	NULL	NULL	NULL	7	Using where; Using join buffer (incremental, BNL join)
1	SIMPLE	t8	ref	b_i	b_i	5	test.t5.b	2	Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b AND
(t8.a > 0 OR t8.c IS NULL) AND t6.a>0 AND t7.a>0;
a	b	a	b	a	b	a	b
2	2	1	2	2	2	1	2
2	2	3	2	2	2	1	2
1	1	1	2	1	1	NULL	NULL
1	1	3	2	1	1	NULL	NULL
3	3	NULL	NULL	NULL	NULL	NULL	NULL
DELETE FROM t5;
DELETE FROM t6;
DELETE FROM t7;
DELETE FROM t8;
INSERT INTO t5 VALUES (1,3,0), (3,2,0);
INSERT INTO t6 VALUES (3,3,0);
INSERT INTO t7 VALUES (1,2,0);
INSERT INTO t8 VALUES (1,1,0);
EXPLAIN
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t6 LEFT JOIN t7 ON t7.a=1, t8)
ON (t5.b=t8.b);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
1	SIMPLE	t7	const	PRIMARY	PRIMARY	4	const	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t6 LEFT JOIN t7 ON t7.a=1, t8)
ON (t5.b=t8.b);
a	b	a	b	a	b	a	b
1	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t6 LEFT JOIN t7 ON t7.b=2, t8)
ON (t5.b=t8.b);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
1	SIMPLE	t7	ref	b_i	b_i	5	const	0	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t6 LEFT JOIN t7 ON t7.b=2, t8)
ON (t5.b=t8.b);
a	b	a	b	a	b	a	b
1	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t8, t6 LEFT JOIN t7 ON t7.a=1)
ON (t5.b=t8.b);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t8	ALL	b_i	NULL	NULL	NULL	1	Using where; Using join buffer (flat, BNL join)
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (incremental, BNL join)
1	SIMPLE	t7	const	PRIMARY	PRIMARY	4	const	1	Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t5 LEFT JOIN                
(t8, t6 LEFT JOIN t7 ON t7.a=1)
ON (t5.b=t8.b);
a	b	a	b	a	b	a	b
1	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	NULL	NULL	NULL	NULL	NULL	NULL
DROP TABLE t5,t6,t7,t8;
set join_cache_level=default;
show variables like 'join_cache_level';
Variable_name	Value
join_cache_level	2
set @@optimizer_switch=@save_optimizer_switch_jcl6;
set @optimizer_switch_for_join_nested_test=NULL;
set @join_cache_level_for_join_nested_test=NULL;