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	When subquery with LEFT JOIN is converted into semi-join, it is possible
to construct cases where the LEFT JOIN's ON expression refers to a table
in the current select but not in the current join nest. For example:
  t1 SEMI JOIN (
    t2
    LEFT JOIN (t3 LEFT JOIN t4 ON t4.col=t1.col) ON expr
  )
here, ON t4.col=t1.col" has this property. Let's denote it as
ON-EXPR-HAS-REF-OUTSIDE-NEST.
The optimizer handles LEFT JOINs like so:
- Outer join runtime requires that "inner tables follow outer" in
  any join order.
- Join optimizer enforces this by constructing join orders that follow
  table dependencies as they are specified in TABLE_LIST::dep_tables.
- The dep_tables are set in simplify_joins() according to the contents
  of ON expressions and LEFT JOIN structure.
However, the logic in simplify_joins() failed to account for possible
ON-EXPR-HAS-REF-OUTSIDE-NEST. It assumed that references outside of the
current join nest could only be OUTER_REF_TABLE_BIT or RAND_TABLE_BIT.
The fix was to add the missing logic.
		
	
			
		
			
				
	
	
		
			2183 lines
		
	
	
	
		
			82 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			2183 lines
		
	
	
	
		
			82 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
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;
 | 
						|
set optimizer_search_depth=62;
 | 
						|
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 `test`.`t3`.`c` is 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	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 `test`.`t3`.`c` is null
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t5`.`a` < 3 or `test`.`t5`.`c` is null)
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) and `test`.`t1`.`a` <> 2) where `test`.`t0`.`a` = 1 and `test`.`t1`.`b` = `test`.`t0`.`b` and (`test`.`t2`.`a` >= 4 or `test`.`t2`.`c` is null)
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) 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 `test`.`t2`.`c` is null) and (`test`.`t3`.`a` < 5 or `test`.`t3`.`c` is null) and (`test`.`t4`.`b` = `test`.`t3`.`b` or `test`.`t3`.`c` is null or `test`.`t4`.`c` is null) and (`test`.`t5`.`a` >= 2 or `test`.`t5`.`c` is null) and (`test`.`t6`.`a` >= 4 or `test`.`t6`.`c` is null) and (`test`.`t7`.`a` <= 2 or `test`.`t7`.`c` is null) and (`test`.`t8`.`a` < 1 or `test`.`t8`.`c` is null) and (`test`.`t9`.`b` = `test`.`t8`.`b` or `test`.`t8`.`c` is null)
 | 
						|
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	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	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	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	3	1	6	2	1	1	NULL	NULL	1	1
 | 
						|
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	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	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	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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) 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 `test`.`t2`.`c` is null) and (`test`.`t3`.`a` < 5 or `test`.`t3`.`c` is null) and (`test`.`t4`.`b` = `test`.`t3`.`b` or `test`.`t3`.`c` is null or `test`.`t4`.`c` is null) and (`test`.`t5`.`a` >= 2 or `test`.`t5`.`c` is null) and (`test`.`t6`.`a` >= 4 or `test`.`t6`.`c` is null) and (`test`.`t7`.`a` <= 2 or `test`.`t7`.`c` is null) and (`test`.`t8`.`a` < 1 or `test`.`t8`.`c` is null) and (`test`.`t9`.`b` = `test`.`t8`.`b` or `test`.`t8`.`c` is null)
 | 
						|
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	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)
 | 
						|
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
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) 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 `test`.`t2`.`c` is null) and (`test`.`t3`.`a` < 5 or `test`.`t3`.`c` is null) and (`test`.`t4`.`b` = `test`.`t3`.`b` or `test`.`t3`.`c` is null or `test`.`t4`.`c` is null) and (`test`.`t5`.`a` >= 2 or `test`.`t5`.`c` is null) and (`test`.`t6`.`a` >= 4 or `test`.`t6`.`c` is null) and (`test`.`t7`.`a` <= 2 or `test`.`t7`.`c` is null) and (`test`.`t8`.`a` < 1 or `test`.`t8`.`c` is null) and (`test`.`t8`.`b` = `test`.`t9`.`b` or `test`.`t8`.`c` is null)
 | 
						|
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#$hj	5	test.t0.b	3	100.00	Using where; Using join buffer (flat, BNLH join)
 | 
						|
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (incremental, BNL join)
 | 
						|
1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	7	100.00	Using where; Using join buffer (incremental, BNL join)
 | 
						|
1	SIMPLE	t7	hash_ALL	NULL	#hash#$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
 | 
						|
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
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) 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 `test`.`t2`.`c` is null) and (`test`.`t3`.`a` < 5 or `test`.`t3`.`c` is null) and (`test`.`t4`.`b` = `test`.`t3`.`b` or `test`.`t3`.`c` is null or `test`.`t4`.`c` is null) and (`test`.`t5`.`a` >= 2 or `test`.`t5`.`c` is null) and (`test`.`t6`.`a` >= 4 or `test`.`t6`.`c` is null) and (`test`.`t7`.`a` <= 2 or `test`.`t7`.`c` is null) and (`test`.`t8`.`a` < 1 or `test`.`t8`.`c` is null) and (`test`.`t8`.`b` = `test`.`t9`.`b` or `test`.`t8`.`c` is null)
 | 
						|
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	2	100.00	
 | 
						|
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 | 
						|
1	SIMPLE	t1	ALL	idx_b	NULL	NULL	NULL	7	100.00	Using where; Using join buffer (incremental, BNL join)
 | 
						|
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
 | 
						|
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
 | 
						|
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 `test`.`t3`.`c` is null) and (`test`.`t6`.`b` = 2 or `test`.`t6`.`c` is null) and (`test`.`t5`.`b` = `test`.`t0`.`b` or `test`.`t3`.`c` is null or `test`.`t6`.`c` is null or `test`.`t8`.`c` is null) 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 `test`.`t2`.`c` is null) and (`test`.`t3`.`a` < 5 or `test`.`t3`.`c` is null) and (`test`.`t4`.`b` = `test`.`t3`.`b` or `test`.`t3`.`c` is null or `test`.`t4`.`c` is null) and (`test`.`t5`.`a` >= 2 or `test`.`t5`.`c` is null) and (`test`.`t6`.`a` >= 4 or `test`.`t6`.`c` is null) and (`test`.`t7`.`a` <= 2 or `test`.`t7`.`c` is null) and (`test`.`t8`.`a` < 1 or `test`.`t8`.`c` is null) and (`test`.`t8`.`b` = `test`.`t9`.`b` or `test`.`t8`.`c` is null)
 | 
						|
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	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
 | 
						|
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	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	2	2	6	2	2	2	0	2	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	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
 | 
						|
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	t2	range	b	b	5	NULL	3	Using where; Using index
 | 
						|
1	SIMPLE	t3	ref	c	c	5	test.t2.b	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	t2	range	b	b	5	NULL	3	Using where; Using index
 | 
						|
1	SIMPLE	t3	ref	c	c	5	test.t2.b	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	t3	const	c	NULL	NULL	NULL	1	Impossible ON condition
 | 
						|
1	SIMPLE	t2	const	b	NULL	NULL	NULL	1	Impossible ON condition
 | 
						|
1	SIMPLE	t1	index	NULL	a	5	NULL	21	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	hash_ALL	NULL	#hash#$hj	5	test.t1.c11	0	Using where; Using join buffer (incremental, BNLH 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 'SELECT'
 | 
						|
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 'SELECT'
 | 
						|
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 'SELECT'
 | 
						|
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 'SELECT'
 | 
						|
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	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.t3.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 SELECT 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 SELECT 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 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 `test`.`t3`.`a` is null
 | 
						|
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;
 | 
						|
#
 | 
						|
# MDEV-7992: Nested left joins + 'not exists' optimization
 | 
						|
#
 | 
						|
CREATE TABLE t1(
 | 
						|
K1 INT PRIMARY KEY,
 | 
						|
Name VARCHAR(15)
 | 
						|
);
 | 
						|
INSERT INTO t1 VALUES
 | 
						|
(1,'T1Row1'), (2,'T1Row2');
 | 
						|
CREATE TABLE t2(
 | 
						|
K2 INT PRIMARY KEY,
 | 
						|
K1r INT,
 | 
						|
rowTimestamp DATETIME,
 | 
						|
Event VARCHAR(15)
 | 
						|
);
 | 
						|
INSERT INTO t2 VALUES
 | 
						|
(1, 1, '2015-04-13 10:42:11' ,'T1Row1Event1'),
 | 
						|
(2, 1, '2015-04-13 10:42:12' ,'T1Row1Event2'),
 | 
						|
(3, 1, '2015-04-13 10:42:12' ,'T1Row1Event3');
 | 
						|
SELECT t1a.*, t2a.*,
 | 
						|
t2i.K2 AS K2B, t2i.K1r AS K1rB,
 | 
						|
t2i.rowTimestamp AS rowTimestampB, t2i.Event AS EventB
 | 
						|
FROM 
 | 
						|
t1 t1a JOIN t2 t2a ON t2a.K1r = t1a.K1
 | 
						|
LEFT JOIN 
 | 
						|
( t1 t1i LEFT JOIN t2 t2i ON  t2i.K1r = t1i.K1) 
 | 
						|
ON (t1i.K1 = 1) AND
 | 
						|
(((t2i.K1r = t1a.K1 AND t2i.rowTimestamp > t2a.rowTimestamp ) OR
 | 
						|
(t2i.rowTimestamp = t2a.rowTimestamp AND t2i.K2 > t2a.K2))
 | 
						|
OR (t2i.K2 IS NULL))
 | 
						|
WHERE 
 | 
						|
t2a.K1r = 1 AND t2i.K2 IS NULL;
 | 
						|
K1	Name	K2	K1r	rowTimestamp	Event	K2B	K1rB	rowTimestampB	EventB
 | 
						|
1	T1Row1	3	1	2015-04-13 10:42:12	T1Row1Event3	NULL	NULL	NULL	NULL
 | 
						|
EXPLAIN EXTENDED SELECT t1a.*, t2a.*,
 | 
						|
t2i.K2 AS K2B, t2i.K1r AS K1rB,
 | 
						|
t2i.rowTimestamp AS rowTimestampB, t2i.Event AS EventB
 | 
						|
FROM 
 | 
						|
t1 t1a JOIN t2 t2a ON t2a.K1r = t1a.K1
 | 
						|
LEFT JOIN 
 | 
						|
( t1 t1i LEFT JOIN t2 t2i ON  t2i.K1r = t1i.K1) 
 | 
						|
ON (t1i.K1 = 1) AND
 | 
						|
(((t2i.K1r = t1a.K1 AND t2i.rowTimestamp > t2a.rowTimestamp ) OR
 | 
						|
(t2i.rowTimestamp = t2a.rowTimestamp AND t2i.K2 > t2a.K2))
 | 
						|
OR (t2i.K2 IS NULL))
 | 
						|
WHERE 
 | 
						|
t2a.K1r = 1 AND t2i.K2 IS NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 | 
						|
1	SIMPLE	t1a	const	PRIMARY	PRIMARY	4	const	1	100.00	
 | 
						|
1	SIMPLE	t2a	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 | 
						|
1	SIMPLE	t1i	const	PRIMARY	PRIMARY	4	const	1	100.00	Using index
 | 
						|
1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Not exists
 | 
						|
Warnings:
 | 
						|
Note	1003	select 1 AS `K1`,'T1Row1' AS `Name`,`test`.`t2a`.`K2` AS `K2`,`test`.`t2a`.`K1r` AS `K1r`,`test`.`t2a`.`rowTimestamp` AS `rowTimestamp`,`test`.`t2a`.`Event` AS `Event`,`test`.`t2i`.`K2` AS `K2B`,`test`.`t2i`.`K1r` AS `K1rB`,`test`.`t2i`.`rowTimestamp` AS `rowTimestampB`,`test`.`t2i`.`Event` AS `EventB` from `test`.`t1` `t1a` join `test`.`t2` `t2a` left join (`test`.`t1` `t1i` left join `test`.`t2` `t2i` on(`test`.`t2i`.`K1r` = 1)) on(`test`.`t1i`.`K1` = 1 and (`test`.`t2i`.`K1r` = 1 and `test`.`t2i`.`rowTimestamp` > `test`.`t2a`.`rowTimestamp` or `test`.`t2i`.`rowTimestamp` = `test`.`t2a`.`rowTimestamp` and `test`.`t2i`.`K2` > `test`.`t2a`.`K2` or `test`.`t2i`.`K2` is null)) where `test`.`t2a`.`K1r` = 1 and `test`.`t2i`.`K2` is null
 | 
						|
CREATE VIEW v1 AS 
 | 
						|
SELECT t2i.*
 | 
						|
FROM t1 as t1i LEFT JOIN t2 as t2i ON t2i.K1r = t1i.K1
 | 
						|
WHERE t1i.K1 = 1 ;
 | 
						|
SELECT
 | 
						|
t1a.*, t2a.*, t2b.K2 as K2B, t2b.K1r as K1rB,
 | 
						|
t2b.rowTimestamp as rowTimestampB, t2b.Event as EventB
 | 
						|
FROM
 | 
						|
t1 as t1a JOIN t2 as t2a ON t2a.K1r = t1a.K1
 | 
						|
LEFT JOIN
 | 
						|
v1 as t2b
 | 
						|
ON ((t2b.K1r = t1a.K1 AND t2b.rowTimestamp > t2a.rowTimestamp) OR
 | 
						|
(t2b.rowTimestamp = t2a.rowTimestamp AND t2b.K2 > t2a.K2))
 | 
						|
OR (t2b.K2 IS NULL)
 | 
						|
WHERE
 | 
						|
t1a.K1 = 1 AND 
 | 
						|
t2b.K2 IS NULL;
 | 
						|
K1	Name	K2	K1r	rowTimestamp	Event	K2B	K1rB	rowTimestampB	EventB
 | 
						|
1	T1Row1	3	1	2015-04-13 10:42:12	T1Row1Event3	NULL	NULL	NULL	NULL
 | 
						|
EXPLAIN EXTENDED SELECT
 | 
						|
t1a.*, t2a.*, t2b.K2 as K2B, t2b.K1r as K1rB,
 | 
						|
t2b.rowTimestamp as rowTimestampB, t2b.Event as EventB
 | 
						|
FROM
 | 
						|
t1 as t1a JOIN t2 as t2a ON t2a.K1r = t1a.K1
 | 
						|
LEFT JOIN
 | 
						|
v1 as t2b
 | 
						|
ON ((t2b.K1r = t1a.K1 AND t2b.rowTimestamp > t2a.rowTimestamp) OR
 | 
						|
(t2b.rowTimestamp = t2a.rowTimestamp AND t2b.K2 > t2a.K2))
 | 
						|
OR (t2b.K2 IS NULL)
 | 
						|
WHERE
 | 
						|
t1a.K1 = 1 AND 
 | 
						|
t2b.K2 IS NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 | 
						|
1	SIMPLE	t1a	const	PRIMARY	PRIMARY	4	const	1	100.00	
 | 
						|
1	SIMPLE	t2a	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 | 
						|
1	SIMPLE	t1i	const	PRIMARY	PRIMARY	4	const	1	100.00	Using index
 | 
						|
1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Not exists
 | 
						|
Warnings:
 | 
						|
Note	1003	select 1 AS `K1`,'T1Row1' AS `Name`,`t2a`.`K2` AS `K2`,`t2a`.`K1r` AS `K1r`,`t2a`.`rowTimestamp` AS `rowTimestamp`,`t2a`.`Event` AS `Event`,`test`.`t2i`.`K2` AS `K2B`,`test`.`t2i`.`K1r` AS `K1rB`,`test`.`t2i`.`rowTimestamp` AS `rowTimestampB`,`test`.`t2i`.`Event` AS `EventB` from `test`.`t1` `t1a` join `test`.`t2` `t2a` left join (`test`.`t1` `t1i` left join `test`.`t2` `t2i` on(`test`.`t2i`.`K1r` = 1)) on(`test`.`t1i`.`K1` = 1 and (`test`.`t2i`.`K1r` = 1 and `test`.`t2i`.`rowTimestamp` > `t2a`.`rowTimestamp` or `test`.`t2i`.`rowTimestamp` = `t2a`.`rowTimestamp` and `test`.`t2i`.`K2` > `t2a`.`K2` or `test`.`t2i`.`K2` is null)) where `t2a`.`K1r` = 1 and `test`.`t2i`.`K2` is null
 | 
						|
DROP VIEW v1;
 | 
						|
DROP TABLE t1,t2;
 | 
						|
set optimizer_search_depth= @tmp_mdev621;
 | 
						|
#
 | 
						|
# MDEV-19588: Nested left joins using optimized join cache
 | 
						|
#
 | 
						|
set optimizer_switch='optimize_join_buffer_size=on';
 | 
						|
set @save_join_cache_level= @@join_cache_level;
 | 
						|
set join_cache_level=2;
 | 
						|
CREATE TABLE t1 (i1 int, c1 varchar(20), pk int) engine=myisam;
 | 
						|
CREATE TABLE t2 (pk int, c1 varchar(20), i1 int) engine=myisam;
 | 
						|
INSERT INTO t2 VALUES (7,'a',-912),(8,'a',5);
 | 
						|
CREATE TABLE t3 (pk int, c1 varchar(20), i1 int) engine=myisam;
 | 
						|
INSERT INTO t3 VALUES
 | 
						|
(1,'a',-145),(2,'a',6),(3,'a',1),(7,'a',NULL),(8,'a',889),(9,'a',146),
 | 
						|
(10,'a',177),(16,'a',-433),(17,'a',NULL),(18,'a',2),(19,'a',3),(20,'a',5),
 | 
						|
(21,'a',-484),(22,'a',369),(23,'a',-192),(24,'a',-163),(25,'a',5),(26,'a',NULL);
 | 
						|
SELECT t3.*
 | 
						|
FROM t3 LEFT JOIN t1 LEFT JOIN t2 ON t1.i1 = t2.i1 ON t3.i1 = t1.i1
 | 
						|
WHERE t2.pk < 13 OR t3.i1 IS NULL;
 | 
						|
pk	c1	i1
 | 
						|
7	a	NULL
 | 
						|
17	a	NULL
 | 
						|
26	a	NULL
 | 
						|
explain extended SELECT t3.*
 | 
						|
FROM t3 LEFT JOIN t1 LEFT JOIN t2 ON t1.i1 = t2.i1 ON t3.i1 = t1.i1
 | 
						|
WHERE t2.pk < 13 OR t3.i1 IS NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 | 
						|
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	18	100.00	
 | 
						|
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	Using where; Using join buffer (flat, BNL join)
 | 
						|
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; Using join buffer (incremental, BNL join)
 | 
						|
Warnings:
 | 
						|
Note	1003	select `test`.`t3`.`pk` AS `pk`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`i1` AS `i1` from `test`.`t3` left join (`test`.`t1` left join `test`.`t2` on(`test`.`t2`.`i1` = `test`.`t3`.`i1`)) on(`test`.`t1`.`i1` = `test`.`t3`.`i1`) where `test`.`t2`.`pk` < 13 or `test`.`t3`.`i1` is null
 | 
						|
DROP TABLE t1,t2,t3;
 | 
						|
set join_cache_level= @save_join_cache_level;
 | 
						|
set optimizer_switch=@save_optimizer_switch;
 | 
						|
#
 | 
						|
# MDEV-27624: Nested left joins with not_exists optimization
 | 
						|
#             for most inner left join
 | 
						|
#
 | 
						|
set @save_join_cache_level= @@join_cache_level;
 | 
						|
CREATE TABLE t1 (a INT NOT NULL, b INT, c INT);
 | 
						|
INSERT INTO t1 VALUES (1,1,1), (1,2,1), (1,3,1);
 | 
						|
CREATE TABLE t2(a INT NOT NULL);
 | 
						|
INSERT INTO t2 VALUES (1), (2);
 | 
						|
CREATE TABLE t3(a INT not null, b INT);
 | 
						|
INSERT INTO t3 VALUES (1, 1), (2, 1), (3, 1);
 | 
						|
set join_cache_level = 0;
 | 
						|
EXPLAIN SELECT *
 | 
						|
FROM t1
 | 
						|
LEFT JOIN
 | 
						|
( t2 LEFT JOIN t3 ON t2.a = t3.b )
 | 
						|
ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
 | 
						|
WHERE t1.c = 1 AND t3.a is NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 | 
						|
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
 | 
						|
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists
 | 
						|
SELECT *
 | 
						|
FROM t1
 | 
						|
LEFT JOIN
 | 
						|
( t2 LEFT JOIN t3 ON t2.a = t3.b )
 | 
						|
ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
 | 
						|
WHERE t1.c = 1 AND t3.a is NULL;
 | 
						|
a	b	c	a	a	b
 | 
						|
1	3	1	NULL	NULL	NULL
 | 
						|
set join_cache_level = 2;
 | 
						|
EXPLAIN SELECT *
 | 
						|
FROM t1
 | 
						|
LEFT JOIN
 | 
						|
( t2 LEFT JOIN t3 ON t2.a = t3.b )
 | 
						|
ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
 | 
						|
WHERE t1.c = 1 AND t3.a is NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 | 
						|
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 | 
						|
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists; Using join buffer (incremental, BNL join)
 | 
						|
SELECT *
 | 
						|
FROM t1
 | 
						|
LEFT JOIN
 | 
						|
( t2 LEFT JOIN t3 ON t2.a = t3.b )
 | 
						|
ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
 | 
						|
WHERE t1.c = 1 AND t3.a is NULL;
 | 
						|
a	b	c	a	a	b
 | 
						|
1	3	1	NULL	NULL	NULL
 | 
						|
DROP TABLE t1, t2, t3;
 | 
						|
set join_cache_level= @save_join_cache_level;
 | 
						|
# end of 10.3 tests
 | 
						|
#
 | 
						|
# MDEV-32084: Assertion in best_extension_by_limited_search(), or crash elsewhere in release
 | 
						|
#
 | 
						|
CREATE TABLE t1 (i int);
 | 
						|
INSERT INTO t1 values (1),(2);
 | 
						|
SELECT 1 FROM  t1 WHERE i IN
 | 
						|
(SELECT 1 FROM t1 c
 | 
						|
LEFT JOIN  (t1 a LEFT JOIN t1 b ON t1.i = b.i)  ON c.i = t1.i);
 | 
						|
1
 | 
						|
1
 | 
						|
DROP TABLE t1;
 | 
						|
# end of 10.11 tests
 | 
						|
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	range	PRIMARY,b_i	PRIMARY	4	NULL	2	Using where; Rowid-ordered scan; Using join buffer (flat, BNL join)
 | 
						|
1	SIMPLE	t6	range|filter	PRIMARY,b_i	PRIMARY|b_i	4|5	NULL	3 (86%)	Using where; Rowid-ordered scan; Using join buffer (incremental, BNL join); Using rowid filter
 | 
						|
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	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.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;
 | 
						|
set @@optimizer_switch=@save_optimizer_switch_jcl6;
 | 
						|
set @optimizer_switch_for_join_nested_test=NULL;
 | 
						|
set @join_cache_level_for_join_nested_test=NULL;
 |