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			356 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| drop table if exists t1;
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| create table t1 (id int not null, str char(10), unique(str));
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| explain select * from t1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
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| insert into t1 values (1, null),(2, null),(3, "foo"),(4, "bar");
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| select * from t1 where str is null;
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| id	str
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| 1	NULL
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| 2	NULL
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| select * from t1 where str="foo";
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| id	str
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| 3	foo
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| explain select * from t1 where str is null;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	ref	str	str	11	const	1	Using index condition
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| explain select * from t1 where str="foo";
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	const	str	str	11	const	1	
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| explain select * from t1 ignore key (str) where str="foo";
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
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| explain select * from t1 use key (str,str) where str="foo";
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	const	str	str	11	const	1	
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| explain select * from t1 use key (str,str,foo) where str="foo";
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| ERROR 42000: Key 'foo' doesn't exist in table 't1'
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| explain select * from t1 ignore key (str,str,foo) where str="foo";
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| ERROR 42000: Key 'foo' doesn't exist in table 't1'
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| drop table t1;
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| explain select 1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
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| create table t1 (a int not null);
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| explain select count(*) from t1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
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| insert into t1 values(1);
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| explain select count(*) from t1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
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| insert into t1 values(1);
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| explain select count(*) from t1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
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| drop table t1;
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| set names koi8r;
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| create table <20><><EFBFBD> (<28><><EFBFBD>0 int, <20><><EFBFBD>1 int, key <20><><EFBFBD>0 (<28><><EFBFBD>0), key <20><><EFBFBD>01 (<28><><EFBFBD>0,<2C><><EFBFBD>1));
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| insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (1);
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| insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (2);
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| explain select <20><><EFBFBD>0 from <20><><EFBFBD> where <20><><EFBFBD>0=1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	<09><><EFBFBD>	ref	<09><><EFBFBD>0,<2C><><EFBFBD>01	<09><><EFBFBD>0	5	const	1	Using index
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| drop table <20><><EFBFBD>;
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| set names latin1;
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| select 3 into @v1;
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| explain select 3 into @v1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
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| create table t1(f1 int, f2 int);
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| insert into t1 values (1,1);
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| create view v1 as select * from t1 where f1=1;
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| explain extended select * from v1 where f2=1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| Warnings:
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| Note	1003	select 1 AS `f1`,1 AS `f2` from dual where 1
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| explain extended select * from t1 where 0;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
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| Warnings:
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| Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 0
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| explain extended select * from t1 where 1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| Warnings:
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| Note	1003	select 1 AS `f1`,1 AS `f2` from dual where 1
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| explain extended select * from t1 having 0;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible HAVING
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| Warnings:
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| Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` having 0
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| explain extended select * from t1 having 1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| Warnings:
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| Note	1003	select 1 AS `f1`,1 AS `f2` from dual having 1
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| drop view v1;
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| drop table t1;
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| CREATE TABLE t1(c INT);
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| INSERT INTO t1 VALUES (),();
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| CREATE TABLE t2 (b INT,
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
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| KEY(b),KEY(b),KEY(b),KEY(b),KEY(b));
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| INSERT INTO t2 VALUES (),(),();
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| EXPLAIN SELECT 1 FROM
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| (SELECT 1 FROM t2,t1 WHERE b < c GROUP BY 1 LIMIT 1) AS d2;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| X	X	X	X	X	X	X	X	X	
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| X	X	X	X	X	X	X	X	X	
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| X	X	X	X	X	X	X	X	X	Range checked for each record (index map: 0xFFFFFFFFFF)
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| DROP TABLE t2;
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| DROP TABLE t1;
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| CREATE TABLE t1(a INT);
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| CREATE TABLE t2(a INT);
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| INSERT INTO t1 VALUES (1),(2);
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| INSERT INTO t2 VALUES (1),(2);
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| EXPLAIN EXTENDED SELECT 1
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| FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	100.00	
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| 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
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| 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
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| Warnings:
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| Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
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| EXPLAIN EXTENDED SELECT 1
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| FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	100.00	
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| 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
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| 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
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| Warnings:
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| Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
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| prepare s1 from 
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| 'EXPLAIN EXTENDED SELECT 1  
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|  FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
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| execute s1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	100.00	
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| 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
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| 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
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| Warnings:
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| Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
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| prepare s1 from 
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| 'EXPLAIN EXTENDED SELECT 1  
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|  FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
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| execute s1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	100.00	
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| 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
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| 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
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| Warnings:
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| Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
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| execute s1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	100.00	
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| 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
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| 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
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| Warnings:
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| Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
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| DROP TABLE t1,t2;
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| CREATE TABLE t1 (a INT PRIMARY KEY);
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| EXPLAIN EXTENDED SELECT COUNT(a) FROM t1 USE KEY(a);
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| ERROR 42000: Key 'a' doesn't exist in table 't1'
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| DROP TABLE t1;
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| CREATE TABLE t1(a LONGTEXT);
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| INSERT INTO t1 VALUES (repeat('a',@@global.max_allowed_packet));
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| INSERT INTO t1 VALUES (repeat('b',@@global.max_allowed_packet));
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| EXPLAIN SELECT DISTINCT 1 FROM t1,
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| (SELECT DISTINCTROW a AS away FROM t1 GROUP BY a WITH ROLLUP) as d1
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| WHERE t1.a = d1.a;
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| ERROR 42S22: Unknown column 'd1.a' in 'where clause'
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| DROP TABLE t1;
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| #
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| # Bug#48295:
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| # explain extended crash with subquery and ONLY_FULL_GROUP_BY sql_mode
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| #
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| CREATE TABLE t1 (f1 INT not null);
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| SELECT @@session.sql_mode INTO @old_sql_mode;
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| SET SESSION sql_mode='ONLY_FULL_GROUP_BY';
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| EXPLAIN EXTENDED SELECT 1 FROM t1
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| WHERE f1 > ALL( SELECT t.f1 FROM t1,t1 AS t );
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
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| 2	SUBQUERY	t1	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
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| 2	SUBQUERY	t	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
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| Warnings:
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| Note	1003	select 1 AS `1` from `test`.`t1` where 0
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| SET SESSION sql_mode=@old_sql_mode;
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| DROP TABLE t1;
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| End of 5.0 tests.
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| #
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| # Bug#37870: Usage of uninitialized value caused failed assertion.
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| #
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| create table t1 (dt datetime not null, t time not null);
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| create table t2 (dt datetime not null);
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| insert into t1 values ('2001-01-01 1:1:1', '1:1:1'),
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| ('2001-01-01 1:1:1', '1:1:1');
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| insert into t2 values ('2001-01-01 1:1:1'), ('2001-01-01 1:1:1');
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| SET @save_join_cache_level=@@join_cache_level;
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| SET join_cache_level=0;
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| flush tables;
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| EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
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| 1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; FirstMatch(OUTR)
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| flush tables;
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| SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
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| dt
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| flush tables;
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| EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	OUTR	ALL	NULL	NULL	NULL	NULL	2	Using where
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| 1	PRIMARY	INNR	ALL	NULL	NULL	NULL	NULL	2	Using where; FirstMatch(OUTR)
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| flush tables;
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| SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
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| dt
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| 2001-01-01 01:01:01
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| 2001-01-01 01:01:01
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| SET join_cache_level=@save_join_cache_level;
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| drop tables t1, t2;
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| #
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| # Bug#47669: Query showed by EXPLAIN EXTENDED gives different result from original query
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| #
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| CREATE TABLE t1 (c int);
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| INSERT INTO t1 VALUES (NULL);
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| CREATE TABLE t2 (d int);
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| INSERT INTO t2 VALUES (NULL), (0);
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| EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = c) FROM t1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| 2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
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| Warnings:
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| Note	1276	Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
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| Note	1003	select <expr_cache><NULL>((select 1 from `test`.`t2` where (`test`.`t2`.`d` = NULL))) AS `(SELECT 1 FROM t2 WHERE d = c)` from dual
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| DROP TABLE t1, t2;
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| #
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| # Bug#30302: Tables that were optimized away are printed in the
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| #            EXPLAIN EXTENDED warning.
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| #
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| create table t1(f1 int);
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| create table t2(f2 int);
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| insert into t1 values(1);
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| insert into t2 values(1),(2);
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| explain extended select * from t1 where f1=1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| Warnings:
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| Note	1003	select 1 AS `f1` from dual where 1
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| explain extended select * from t1 join t2 on f1=f2 where f1=1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	100.00	
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| 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
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| Warnings:
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| Note	1003	select 1 AS `f1`,`test`.`t2`.`f2` AS `f2` from `test`.`t2` where (`test`.`t2`.`f2` = 1)
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| drop table t1,t2;
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| #
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| # Bug #48419: another explain crash..
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| #
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| CREATE TABLE t1 (a INT);
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| CREATE TABLE t2 (b BLOB, KEY b(b(100)));
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| INSERT INTO t2 VALUES ('1'), ('2'), ('3');
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| FLUSH TABLES;
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| EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT 1 FROM t1 t JOIN t2 WHERE b <= 1 AND t.a);
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
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| 2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
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| DROP TABLE t1, t2;
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| #
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| # Bug #48573: difference of index selection between rpm binary and
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| #             .tar.gz, windows vs linux..
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| #
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| CREATE TABLE t1(c1 INT, c2 INT, c4 INT, c5 INT, KEY(c2, c5), KEY(c2, c4, c5));
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| INSERT INTO t1 VALUES(4, 1, 1, 1);
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| INSERT INTO t1 VALUES(3, 1, 1, 1);
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| INSERT INTO t1 VALUES(2, 1, 1, 1);
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| INSERT INTO t1 VALUES(1, 1, 1, 1);
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| EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	SIMPLE	t1	ref	c2,c2_2	c2	10	const,const	3	Using where
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| DROP TABLE t1;
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| #
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| # Bug#56814 Explain + subselect + fulltext crashes server
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| #
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| CREATE TABLE t1(f1 VARCHAR(6) NOT NULL,
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| FULLTEXT KEY(f1),UNIQUE(f1));
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| INSERT INTO t1 VALUES ('test');
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| EXPLAIN SELECT 1 FROM t1
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| WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST (""))
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| WHERE t1.f1 GROUP BY t1.f1));
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
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| PREPARE stmt FROM
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| 'EXPLAIN SELECT 1 FROM t1
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|  WHERE 1 > ALL((SELECT t1.f1 FROM t1 RIGHT OUTER JOIN t1 a
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|  ON (MATCH(t1.f1) AGAINST (""))
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|  WHERE t1.f1 GROUP BY t1.f1))';
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| EXECUTE stmt;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
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| EXECUTE stmt;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
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| DEALLOCATE PREPARE stmt;
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| PREPARE stmt FROM
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| 'EXPLAIN SELECT 1 FROM t1
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|  WHERE 1 > ALL((SELECT t1.f1 FROM t1 JOIN t1 a
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|  ON (MATCH(t1.f1) AGAINST (""))
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|  WHERE t1.f1 GROUP BY t1.f1))';
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| EXECUTE stmt;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
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| EXECUTE stmt;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
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| 1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	a	system	NULL	NULL	NULL	NULL	1	
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| 2	SUBQUERY	t1	fulltext	f1_2,f1	f1	0		1	Using where
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| DEALLOCATE PREPARE stmt;
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| DROP TABLE t1;
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| End of 5.1 tests.
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| #
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| # Bug#11829785 EXPLAIN EXTENDED CRASH WITH RIGHT OUTER JOIN, SUBQUERIES
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| #
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| CREATE TABLE t1(a INT);
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| INSERT INTO t1 VALUES (0), (0);
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| PREPARE s FROM 
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| 'EXPLAIN EXTENDED
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| SELECT SUBSTRING(1, (SELECT 1 FROM t1 a1 RIGHT OUTER JOIN t1 ON 0)) AS d
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| FROM t1 WHERE 0 > ANY (SELECT @a FROM t1)';
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| EXECUTE s;
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| ERROR 21000: Subquery returns more than 1 row
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| DEALLOCATE PREPARE s;
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| DROP TABLE t1;
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| #
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| # Bug#776295: EXPLAIN EXTENDED with always false multiple equality
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| #             in the WHERE condition of a derived table
 | ||
| #
 | ||
| CREATE TABLE t1 (a int) ;
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| CREATE TABLE t2 (a int) ;
 | ||
| INSERT INTO t2 VALUES (8);
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| set @tmp_optimizer_switch=@@optimizer_switch;
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| set optimizer_switch='derived_merge=off,derived_with_keys=off';
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| EXPLAIN EXTENDED
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| SELECT * FROM ( SELECT t1.a FROM t1,t2 WHERE t2.a = t1.a ) AS t;
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| id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
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| 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	0.00	const row not found
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| 2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
 | ||
| Warnings:
 | ||
| Note	1003	select NULL AS `a` from (select NULL AS `a` from `test`.`t1` where 0) `t`
 | ||
| set optimizer_switch=@tmp_optimizer_switch;
 | ||
| DROP TABLE t1,t2;
 |