735 lines
		
	
	
		
			41 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
		
		
			
		
	
	
			735 lines
		
	
	
		
			41 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
|  | drop table if exists t1,t2,t3,t4,t5,t6,t7; | ||
|  | create table t1 ( | ||
|  | c11 integer,c12 integer,c13 integer,c14 integer,c15 integer,c16 integer, | ||
|  | primary key (c11) | ||
|  | ); | ||
|  | create table t2 ( | ||
|  | c21 integer,c22 integer,c23 integer,c24 integer,c25 integer,c26 integer | ||
|  | ); | ||
|  | create table t3 ( | ||
|  | c31 integer,c32 integer,c33 integer,c34 integer,c35 integer,c36 integer, | ||
|  | primary key (c31) | ||
|  | ); | ||
|  | create table t4 ( | ||
|  | c41 integer,c42 integer,c43 integer,c44 integer,c45 integer,c46 integer | ||
|  | ); | ||
|  | create table t5 ( | ||
|  | c51 integer,c52 integer,c53 integer,c54 integer,c55 integer,c56 integer, | ||
|  | primary key (c51) | ||
|  | ); | ||
|  | create table t6 ( | ||
|  | c61 integer,c62 integer,c63 integer,c64 integer,c65 integer,c66 integer | ||
|  | ); | ||
|  | create table t7 ( | ||
|  | c71 integer,c72 integer,c73 integer,c74 integer,c75 integer,c76 integer, | ||
|  | primary key (c71) | ||
|  | ); | ||
|  | insert into t1 values (1,2,3,4,5,6); | ||
|  | insert into t1 values (2,2,3,4,5,6); | ||
|  | insert into t1 values (3,2,3,4,5,6); | ||
|  | insert into t2 values (1,2,3,4,5,6); | ||
|  | insert into t2 values (2,2,3,4,5,6); | ||
|  | insert into t2 values (3,2,3,4,5,6); | ||
|  | insert into t2 values (4,2,3,4,5,6); | ||
|  | insert into t2 values (5,2,3,4,5,6); | ||
|  | insert into t2 values (6,2,3,4,5,6); | ||
|  | insert into t3 values (1,2,3,4,5,6); | ||
|  | insert into t3 values (2,2,3,4,5,6); | ||
|  | insert into t3 values (3,2,3,4,5,6); | ||
|  | insert into t3 values (4,2,3,4,5,6); | ||
|  | insert into t3 values (5,2,3,4,5,6); | ||
|  | insert into t3 values (6,2,3,4,5,6); | ||
|  | insert into t3 values (7,2,3,4,5,6); | ||
|  | insert into t3 values (8,2,3,4,5,6); | ||
|  | insert into t3 values (9,2,3,4,5,6); | ||
|  | insert into t4 values (1,2,3,4,5,6); | ||
|  | insert into t4 values (2,2,3,4,5,6); | ||
|  | insert into t4 values (3,2,3,4,5,6); | ||
|  | insert into t4 values (4,2,3,4,5,6); | ||
|  | insert into t4 values (5,2,3,4,5,6); | ||
|  | insert into t4 values (6,2,3,4,5,6); | ||
|  | insert into t4 values (7,2,3,4,5,6); | ||
|  | insert into t4 values (8,2,3,4,5,6); | ||
|  | insert into t4 values (9,2,3,4,5,6); | ||
|  | insert into t4 values (10,2,3,4,5,6); | ||
|  | insert into t4 values (11,2,3,4,5,6); | ||
|  | insert into t4 values (12,2,3,4,5,6); | ||
|  | insert into t5 values (1,2,3,4,5,6); | ||
|  | insert into t5 values (2,2,3,4,5,6); | ||
|  | insert into t5 values (3,2,3,4,5,6); | ||
|  | insert into t5 values (4,2,3,4,5,6); | ||
|  | insert into t5 values (5,2,3,4,5,6); | ||
|  | insert into t5 values (6,2,3,4,5,6); | ||
|  | insert into t5 values (7,2,3,4,5,6); | ||
|  | insert into t5 values (8,2,3,4,5,6); | ||
|  | insert into t5 values (9,2,3,4,5,6); | ||
|  | insert into t5 values (10,2,3,4,5,6); | ||
|  | insert into t5 values (11,2,3,4,5,6); | ||
|  | insert into t5 values (12,2,3,4,5,6); | ||
|  | insert into t5 values (13,2,3,4,5,6); | ||
|  | insert into t5 values (14,2,3,4,5,6); | ||
|  | insert into t5 values (15,2,3,4,5,6); | ||
|  | insert into t6 values (1,2,3,4,5,6); | ||
|  | insert into t6 values (2,2,3,4,5,6); | ||
|  | insert into t6 values (3,2,3,4,5,6); | ||
|  | insert into t6 values (4,2,3,4,5,6); | ||
|  | insert into t6 values (5,2,3,4,5,6); | ||
|  | insert into t6 values (6,2,3,4,5,6); | ||
|  | insert into t6 values (7,2,3,4,5,6); | ||
|  | insert into t6 values (8,2,3,4,5,6); | ||
|  | insert into t6 values (9,2,3,4,5,6); | ||
|  | insert into t6 values (10,2,3,4,5,6); | ||
|  | insert into t6 values (11,2,3,4,5,6); | ||
|  | insert into t6 values (12,2,3,4,5,6); | ||
|  | insert into t6 values (13,2,3,4,5,6); | ||
|  | insert into t6 values (14,2,3,4,5,6); | ||
|  | insert into t6 values (15,2,3,4,5,6); | ||
|  | insert into t6 values (16,2,3,4,5,6); | ||
|  | insert into t6 values (17,2,3,4,5,6); | ||
|  | insert into t6 values (18,2,3,4,5,6); | ||
|  | insert into t7 values (1,2,3,4,5,6); | ||
|  | insert into t7 values (2,2,3,4,5,6); | ||
|  | insert into t7 values (3,2,3,4,5,6); | ||
|  | insert into t7 values (4,2,3,4,5,6); | ||
|  | insert into t7 values (5,2,3,4,5,6); | ||
|  | insert into t7 values (6,2,3,4,5,6); | ||
|  | insert into t7 values (7,2,3,4,5,6); | ||
|  | insert into t7 values (8,2,3,4,5,6); | ||
|  | insert into t7 values (9,2,3,4,5,6); | ||
|  | insert into t7 values (10,2,3,4,5,6); | ||
|  | insert into t7 values (11,2,3,4,5,6); | ||
|  | insert into t7 values (12,2,3,4,5,6); | ||
|  | insert into t7 values (13,2,3,4,5,6); | ||
|  | insert into t7 values (14,2,3,4,5,6); | ||
|  | insert into t7 values (15,2,3,4,5,6); | ||
|  | insert into t7 values (16,2,3,4,5,6); | ||
|  | insert into t7 values (17,2,3,4,5,6); | ||
|  | insert into t7 values (18,2,3,4,5,6); | ||
|  | insert into t7 values (19,2,3,4,5,6); | ||
|  | insert into t7 values (20,2,3,4,5,6); | ||
|  | insert into t7 values (21,2,3,4,5,6); | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 62 | ||
|  | select @@optimizer_prune_level; | ||
|  | @@optimizer_prune_level | ||
|  | 1 | ||
|  | set optimizer_search_depth=63; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 63 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | set optimizer_prune_level=0; | ||
|  | select @@optimizer_prune_level; | ||
|  | @@optimizer_prune_level | ||
|  | 0 | ||
|  | set optimizer_search_depth=0; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 0 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | set optimizer_search_depth=1; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 1 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	 | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	 | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | set optimizer_search_depth=62; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 62 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	289.418727 | ||
|  | set optimizer_prune_level=1; | ||
|  | select @@optimizer_prune_level; | ||
|  | @@optimizer_prune_level | ||
|  | 1 | ||
|  | set optimizer_search_depth=0; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 0 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | set optimizer_search_depth=1; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 1 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	 | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	 | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | set optimizer_search_depth=62; | ||
|  | select @@optimizer_search_depth; | ||
|  | @@optimizer_search_depth | ||
|  | 62 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	 | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	 | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	821.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76; | ||
|  | id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra | ||
|  | 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	 | ||
|  | 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer | ||
|  | 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where | ||
|  | 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer | ||
|  | 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where | ||
|  | 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer | ||
|  | 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where | ||
|  | show status like 'Last_query_cost'; | ||
|  | Variable_name	Value | ||
|  | Last_query_cost	794.837037 | ||
|  | drop table t1,t2,t3,t4,t5,t6,t7; | ||
|  | CREATE TABLE t1 (a int, b int, d int, i int); | ||
|  | INSERT INTO t1 VALUES (1,1,1,1); | ||
|  | CREATE TABLE t2 (b int, c int, j int); | ||
|  | INSERT INTO t2 VALUES (1,1,1); | ||
|  | CREATE TABLE t2_1 (j int); | ||
|  | INSERT INTO t2_1 VALUES (1); | ||
|  | CREATE TABLE t3 (c int, f int); | ||
|  | INSERT INTO t3 VALUES (1,1); | ||
|  | CREATE TABLE t3_1 (f int); | ||
|  | INSERT INTO t3_1 VALUES (1); | ||
|  | CREATE TABLE t4 (d int, e int, k int); | ||
|  | INSERT INTO t4 VALUES (1,1,1); | ||
|  | CREATE TABLE t4_1 (k int); | ||
|  | INSERT INTO t4_1 VALUES (1); | ||
|  | CREATE TABLE t5 (g int, d int, h int, l int); | ||
|  | INSERT INTO t5 VALUES (1,1,1,1); | ||
|  | CREATE TABLE t5_1 (l int); | ||
|  | INSERT INTO t5_1 VALUES (1); | ||
|  | SET optimizer_search_depth = 3; | ||
|  | SELECT 1 | ||
|  | FROM t1 | ||
|  | LEFT JOIN ( | ||
|  | t2 JOIN t3 ON t3.c = t2.c | ||
|  | ) ON t2.b = t1.b | ||
|  | LEFT JOIN ( | ||
|  | t4 JOIN t5 ON t5.d = t4.d | ||
|  | ) ON t4.d = t1.d | ||
|  | ; | ||
|  | 1 | ||
|  | 1 | ||
|  | SELECT 1 | ||
|  | FROM t1 | ||
|  | LEFT JOIN ( | ||
|  | t2 LEFT JOIN (t3 JOIN t3_1 ON t3.f = t3_1.f) ON t3.c = t2.c | ||
|  | ) ON t2.b = t1.b | ||
|  | LEFT JOIN ( | ||
|  | t4 JOIN t5 ON t5.d = t4.d | ||
|  | ) ON t4.d = t1.d | ||
|  | ; | ||
|  | 1 | ||
|  | 1 | ||
|  | SELECT 1 | ||
|  | FROM t1 | ||
|  | LEFT JOIN ( | ||
|  | (t2 JOIN t2_1 ON t2.j = t2_1.j) JOIN t3 ON t3.c = t2.c | ||
|  | ) ON t2.b = t1.b | ||
|  | LEFT JOIN ( | ||
|  | t4 JOIN t5 ON t5.d = t4.d | ||
|  | ) ON t4.d = t1.d | ||
|  | ; | ||
|  | 1 | ||
|  | 1 | ||
|  | SELECT 1 | ||
|  | FROM t1 | ||
|  | LEFT JOIN ( | ||
|  | t2 JOIN t3 ON t3.c = t2.c | ||
|  | ) ON t2.b = t1.b | ||
|  | LEFT JOIN ( | ||
|  | (t4 JOIN t4_1 ON t4.k = t4_1.k) LEFT JOIN t5 ON t5.d = t4.d | ||
|  | ) ON t4.d = t1.d | ||
|  | ; | ||
|  | 1 | ||
|  | 1 | ||
|  | SELECT 1 | ||
|  | FROM t1 | ||
|  | LEFT JOIN ( | ||
|  | t2 JOIN t3 ON t3.c = t2.c | ||
|  | ) ON t2.b = t1.b | ||
|  | LEFT JOIN ( | ||
|  | t4 LEFT JOIN (t5 JOIN t5_1 ON t5.l = t5_1.l) ON t5.d = t4.d | ||
|  | ) ON t4.d = t1.d | ||
|  | ; | ||
|  | 1 | ||
|  | 1 | ||
|  | SET optimizer_search_depth = DEFAULT; | ||
|  | DROP TABLE t1,t2,t2_1,t3,t3_1,t4,t4_1,t5,t5_1; | ||
|  | End of 5.0 tests |