mariadb/mysql-test/r/explain.result

drop table if exists t1;
create table t1 (id int not null, str char(10), unique(str));
explain select * from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	0	const row not found
insert into t1 values (1, null),(2, null),(3, "foo"),(4, "bar");
select * from t1 where str is null;
id	str
1	NULL
2	NULL
select * from t1 where str="foo";
id	str
3	foo
explain select * from t1 where str is null;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	str	str	11	const	1	Using where
explain select * from t1 where str="foo";
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	const	str	str	11	const	1	
explain select * from t1 ignore key (str) where str="foo";
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
explain select * from t1 use key (str,str) where str="foo";
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	const	str	str	11	const	1	
explain select * from t1 use key (str,str,foo) where str="foo";
ERROR HY000: Key 'foo' doesn't exist in table 't1'
explain select * from t1 ignore key (str,str,foo) where str="foo";
ERROR HY000: Key 'foo' doesn't exist in table 't1'
drop table t1;
explain select 1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
create table t1 (a int not null);
explain select count(*) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
insert into t1 values(1);
explain select count(*) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
insert into t1 values(1);
explain select count(*) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
drop table t1;
set names koi8r;
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));
insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (1);
insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (2);
explain select <20><><EFBFBD>0 from <20><><EFBFBD> where <20><><EFBFBD>0=1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	<09><><EFBFBD>	ref	<09><><EFBFBD>0,<2C><><EFBFBD>01	<09><><EFBFBD>0	5	const	1	Using where; Using index
drop table <20><><EFBFBD>;
set names latin1;
select 3 into @v1;
explain select 3 into @v1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
create table t1(f1 int, f2 int);
insert into t1 values (1,1);
create view v1 as select * from t1 where f1=1;
explain extended select * from v1 where f2=1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
Warnings:
Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
explain extended select * from t1 where 0;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
Warnings:
Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 0
explain extended select * from t1 where 1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
Warnings:
Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
explain extended select * from t1 having 0;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible HAVING
Warnings:
Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` having 0
explain extended select * from t1 having 1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
Warnings:
Note	1003	select '1' AS `f1`,'1' AS `f2` from `test`.`t1` having 1
drop view v1;
drop table t1;
CREATE TABLE t1(c INT);
INSERT INTO t1 VALUES (),();
CREATE TABLE t2 (b INT,
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b));
INSERT INTO t2 VALUES (),(),();
EXPLAIN SELECT 1 FROM
(SELECT 1 FROM t2,t1 WHERE b < c GROUP BY 1 LIMIT 1) AS d2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
X	X	X	X	X	X	X	X	X	const row not found
X	X	X	X	X	X	X	X	X	
X	X	X	X	X	X	X	X	X	Range checked for each record (index map: 0xFFFFFFFFFF)
DROP TABLE t2;
DROP TABLE t1;
CREATE TABLE t1(a INT);
CREATE TABLE t2(a INT);
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t2 VALUES (1),(2);
EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
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`
EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
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`
prepare s1 from 
'EXPLAIN EXTENDED SELECT 1  
 FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
execute s1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
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`
prepare s1 from 
'EXPLAIN EXTENDED SELECT 1  
 FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
execute s1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
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`
execute s1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
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`
DROP TABLE t1,t2;