mirror of
https://github.com/MariaDB/server.git
synced 2025-10-31 15:50:51 +03:00
c15b2e4152
The bug could cause choosing a sub-optimal execution plan for a single-table query if a unique index with many null keys were defined for the table. It happened because the code of the check_quick_keys function made an assumption that any key may occur in an unique index only once. Yet this is not true for keys with nulls that may have multiple occurrences in the index. mysql-test/r/null_key.result: Fixed bug #25407 Adjusted result after the fix. mysql-test/r/select.result: Added a test case for bug #25407. mysql-test/t/select.test: Added a test case for bug #25407.
432 lines
14 KiB
Plaintext
432 lines
14 KiB
Plaintext
drop table if exists t1,t2;
|
|
create table t1 (a int, b int not null,unique key (a,b),index(b)) engine=myisam;
|
|
insert ignore into t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(null,7),(9,9),(8,8),(7,7),(null,9),(null,9),(6,6);
|
|
explain select * from t1 where a is null;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a a 5 const 3 Using where; Using index
|
|
explain select * from t1 where a is null and b = 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 9 const,const 1 Using where; Using index
|
|
explain select * from t1 where a is null and b = 7;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 9 const,const 1 Using where; Using index
|
|
explain select * from t1 where a=2 and b = 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 const a,b a 9 const,const 1 Using index
|
|
explain select * from t1 where a<=>b limit 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 index NULL a 9 NULL 12 Using where; Using index
|
|
explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a,b a 9 NULL 3 Using where; Using index
|
|
explain select * from t1 where (a is null or a = 7) and b=7;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using where; Using index
|
|
explain select * from t1 where (a is null or a = 7) and b=7 order by a;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using where; Using index; Using filesort
|
|
explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where; Using index
|
|
explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a,b a 9 NULL 3 Using where; Using index
|
|
explain select * from t1 where a > 1 and a < 3 limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a a 5 NULL 1 Using where; Using index
|
|
explain select * from t1 where a > 8 and a < 9;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a a 5 NULL 1 Using where; Using index
|
|
select * from t1 where a is null;
|
|
a b
|
|
NULL 7
|
|
NULL 9
|
|
NULL 9
|
|
select * from t1 where a is null and b = 7;
|
|
a b
|
|
NULL 7
|
|
select * from t1 where a<=>b limit 2;
|
|
a b
|
|
1 1
|
|
2 2
|
|
select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
|
|
a b
|
|
1 1
|
|
2 2
|
|
select * from t1 where (a is null or a > 0 and a < 3) and b > 7 limit 3;
|
|
a b
|
|
NULL 9
|
|
NULL 9
|
|
select * from t1 where (a is null or a = 7) and b=7;
|
|
a b
|
|
7 7
|
|
NULL 7
|
|
select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
|
|
a b
|
|
NULL 7
|
|
NULL 9
|
|
NULL 9
|
|
select * from t1 where a > 1 and a < 3 limit 1;
|
|
a b
|
|
2 2
|
|
select * from t1 where a > 8 and a < 9;
|
|
a b
|
|
create table t2 like t1;
|
|
insert into t2 select * from t1;
|
|
alter table t1 modify b blob not null, add c int not null, drop key a, add unique key (a,b(20),c), drop key b, add key (b(10));
|
|
explain select * from t1 where a is null and b = 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where
|
|
explain select * from t1 where a is null and b = 2 and c=0;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where
|
|
explain select * from t1 where a is null and b = 7 and c=0;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where
|
|
explain select * from t1 where a=2 and b = 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 1 Using where
|
|
explain select * from t1 where a<=>b limit 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 12 Using where
|
|
explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 and c=0 limit 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a,b a 5 NULL 5 Using where
|
|
explain select * from t1 where (a is null or a = 7) and b=7 and c=0;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a,b a 5 const 4 Using where
|
|
explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where
|
|
explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref a,b a 5 const 3 Using where
|
|
explain select * from t1 where a > 1 and a < 3 limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a a 5 NULL 1 Using where
|
|
explain select * from t1 where a is null and b=7 or a > 1 and a < 3 limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a,b a 5 NULL 4 Using where
|
|
explain select * from t1 where a > 8 and a < 9;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range a a 5 NULL 1 Using where
|
|
explain select * from t1 where b like "6%";
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 range b b 12 NULL 1 Using where
|
|
select * from t1 where a is null;
|
|
a b c
|
|
NULL 7 0
|
|
NULL 9 0
|
|
NULL 9 0
|
|
select * from t1 where a is null and b = 7 and c=0;
|
|
a b c
|
|
NULL 7 0
|
|
select * from t1 where a<=>b limit 2;
|
|
a b c
|
|
1 1 0
|
|
2 2 0
|
|
select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
|
|
a b c
|
|
1 1 0
|
|
2 2 0
|
|
select * from t1 where (a is null or a > 0 and a < 3) and b > 7 limit 3;
|
|
a b c
|
|
NULL 9 0
|
|
NULL 9 0
|
|
select * from t1 where (a is null or a = 7) and b=7 and c=0;
|
|
a b c
|
|
7 7 0
|
|
NULL 7 0
|
|
select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
|
|
a b c
|
|
NULL 7 0
|
|
NULL 9 0
|
|
NULL 9 0
|
|
select * from t1 where b like "6%";
|
|
a b c
|
|
6 6 0
|
|
drop table t1;
|
|
rename table t2 to t1;
|
|
alter table t1 modify b int null;
|
|
insert into t1 values (7,null), (8,null), (8,7);
|
|
explain select * from t1 where a = 7 and (b=7 or b is null);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a,b a 10 const,const 2 Using where; Using index
|
|
select * from t1 where a = 7 and (b=7 or b is null);
|
|
a b
|
|
7 7
|
|
7 NULL
|
|
explain select * from t1 where (a = 7 or a is null) and (b=7 or b is null);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a,b a 5 const 4 Using where; Using index
|
|
select * from t1 where (a = 7 or a is null) and (b=7 or b is null);
|
|
a b
|
|
7 NULL
|
|
7 7
|
|
NULL 7
|
|
explain select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref_or_null a a 5 const 5 Using where; Using index
|
|
select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
|
|
a b
|
|
7 NULL
|
|
7 7
|
|
NULL 7
|
|
NULL 9
|
|
NULL 9
|
|
create table t2 (a int);
|
|
insert into t2 values (7),(8);
|
|
explain select * from t2 straight_join t1 where t1.a=t2.a and b is null;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
|
|
1 SIMPLE t1 ref a,b a 10 test.t2.a,const 2 Using where; Using index
|
|
drop index b on t1;
|
|
explain select * from t2,t1 where t1.a=t2.a and b is null;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
|
|
1 SIMPLE t1 ref a a 10 test.t2.a,const 2 Using where; Using index
|
|
select * from t2,t1 where t1.a=t2.a and b is null;
|
|
a a b
|
|
7 7 NULL
|
|
8 8 NULL
|
|
explain select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
|
|
1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using where; Using index
|
|
select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
|
|
a a b
|
|
7 7 7
|
|
7 7 NULL
|
|
8 8 7
|
|
8 8 NULL
|
|
explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
|
|
1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using where; Using index
|
|
select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
|
|
a a b
|
|
7 7 7
|
|
7 NULL 7
|
|
8 8 7
|
|
8 NULL 7
|
|
explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and (b= 7 or b is null);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 2
|
|
1 SIMPLE t1 ref_or_null a a 5 test.t2.a 4 Using where; Using index
|
|
select * from t2,t1 where (t1.a=t2.a or t1.a is null) and (b= 7 or b is null);
|
|
a a b
|
|
7 7 NULL
|
|
7 7 7
|
|
7 NULL 7
|
|
8 8 NULL
|
|
8 8 7
|
|
8 NULL 7
|
|
insert into t2 values (null),(6);
|
|
delete from t1 where a=8;
|
|
explain select * from t2,t1 where t1.a=t2.a or t1.a is null;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 4
|
|
1 SIMPLE t1 ref_or_null a a 5 test.t2.a 4 Using where; Using index
|
|
explain select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t2 ALL NULL NULL NULL NULL 4
|
|
1 SIMPLE t1 ref_or_null a a 5 test.t2.a 4 Using where; Using index
|
|
select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
|
|
a a b
|
|
7 7 NULL
|
|
7 7 7
|
|
7 NULL 7
|
|
8 NULL 7
|
|
NULL NULL 7
|
|
NULL NULL 9
|
|
NULL NULL 9
|
|
6 6 6
|
|
6 NULL 7
|
|
drop table t1,t2;
|
|
CREATE TABLE t1 (
|
|
id int(10) unsigned NOT NULL auto_increment,
|
|
uniq_id int(10) unsigned default NULL,
|
|
PRIMARY KEY (id),
|
|
UNIQUE KEY idx1 (uniq_id)
|
|
) ENGINE=MyISAM;
|
|
CREATE TABLE t2 (
|
|
id int(10) unsigned NOT NULL auto_increment,
|
|
uniq_id int(10) unsigned default NULL,
|
|
PRIMARY KEY (id)
|
|
) ENGINE=MyISAM;
|
|
INSERT INTO t1 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
|
|
INSERT INTO t2 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
|
|
explain select id from t1 where uniq_id is null;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ref idx1 idx1 5 const 5 Using where
|
|
explain select id from t1 where uniq_id =1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 const idx1 idx1 5 const 1
|
|
UPDATE t1 SET id=id+100 where uniq_id is null;
|
|
UPDATE t2 SET id=id+100 where uniq_id is null;
|
|
select id from t1 where uniq_id is null;
|
|
id
|
|
101
|
|
102
|
|
105
|
|
106
|
|
109
|
|
110
|
|
select id from t2 where uniq_id is null;
|
|
id
|
|
101
|
|
102
|
|
105
|
|
106
|
|
109
|
|
110
|
|
DELETE FROM t1 WHERE uniq_id IS NULL;
|
|
DELETE FROM t2 WHERE uniq_id IS NULL;
|
|
SELECT * FROM t1 ORDER BY uniq_id, id;
|
|
id uniq_id
|
|
3 1
|
|
4 2
|
|
7 3
|
|
8 4
|
|
SELECT * FROM t2 ORDER BY uniq_id, id;
|
|
id uniq_id
|
|
3 1
|
|
4 2
|
|
7 3
|
|
8 4
|
|
DROP table t1,t2;
|
|
CREATE TABLE `t1` (
|
|
`order_id` char(32) NOT NULL default '',
|
|
`product_id` char(32) NOT NULL default '',
|
|
`product_type` int(11) NOT NULL default '0',
|
|
PRIMARY KEY (`order_id`,`product_id`,`product_type`)
|
|
) ENGINE=MyISAM;
|
|
CREATE TABLE `t2` (
|
|
`order_id` char(32) NOT NULL default '',
|
|
`product_id` char(32) NOT NULL default '',
|
|
`product_type` int(11) NOT NULL default '0',
|
|
PRIMARY KEY (`order_id`,`product_id`,`product_type`)
|
|
) ENGINE=MyISAM;
|
|
INSERT INTO t1 (order_id, product_id, product_type) VALUES
|
|
('3d7ce39b5d4b3e3d22aaafe9b633de51',1206029, 3),
|
|
('3d7ce39b5d4b3e3d22aaafe9b633de51',5880836, 3),
|
|
('9d9aad7764b5b2c53004348ef8d34500',2315652, 3);
|
|
INSERT INTO t2 (order_id, product_id, product_type) VALUES
|
|
('9d9aad7764b5b2c53004348ef8d34500',2315652, 3);
|
|
select t1.* from t1
|
|
left join t2 using(order_id, product_id, product_type)
|
|
where t2.order_id=NULL;
|
|
order_id product_id product_type
|
|
select t1.* from t1
|
|
left join t2 using(order_id, product_id, product_type)
|
|
where t2.order_id is NULL;
|
|
order_id product_id product_type
|
|
3d7ce39b5d4b3e3d22aaafe9b633de51 1206029 3
|
|
3d7ce39b5d4b3e3d22aaafe9b633de51 5880836 3
|
|
drop table t1,t2;
|
|
create table t1 (id int);
|
|
insert into t1 values (null), (0);
|
|
create table t2 (id int);
|
|
insert into t2 values (null);
|
|
select * from t1, t2 where t1.id = t2.id;
|
|
id id
|
|
alter table t1 add key id (id);
|
|
select * from t1, t2 where t1.id = t2.id;
|
|
id id
|
|
drop table t1,t2;
|
|
create table t1 (
|
|
id integer,
|
|
id2 integer not null,
|
|
index (id),
|
|
index (id2)
|
|
);
|
|
insert into t1 values(null,null),(1,1);
|
|
Warnings:
|
|
Warning 1263 Column was set to data type implicit default; NULL supplied for NOT NULL column 'id2' at row 1
|
|
select * from t1;
|
|
id id2
|
|
NULL 0
|
|
1 1
|
|
select * from t1 where id <=> null;
|
|
id id2
|
|
NULL 0
|
|
select * from t1 where id <=> null or id > 0;
|
|
id id2
|
|
NULL 0
|
|
1 1
|
|
select * from t1 where id is null or id > 0;
|
|
id id2
|
|
NULL 0
|
|
1 1
|
|
select * from t1 where id2 <=> null or id2 > 0;
|
|
id id2
|
|
1 1
|
|
select * from t1 where id2 is null or id2 > 0;
|
|
id id2
|
|
1 1
|
|
delete from t1 where id <=> NULL;
|
|
select * from t1;
|
|
id id2
|
|
1 1
|
|
drop table t1;
|
|
CREATE TABLE t1 (a int);
|
|
CREATE TABLE t2 (a int, b int, INDEX idx(a));
|
|
CREATE TABLE t3 (b int, INDEX idx(b));
|
|
CREATE TABLE t4 (b int, INDEX idx(b));
|
|
INSERT INTO t1 VALUES (1), (2), (3), (4);
|
|
INSERT INTO t2 VALUES (1, 1), (3, 1);
|
|
INSERT INTO t3 VALUES
|
|
(NULL), (NULL), (NULL), (NULL), (NULL),
|
|
(NULL), (NULL), (NULL), (NULL), (NULL);
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t4 SELECT * FROM t3;
|
|
INSERT INTO t3 SELECT * FROM t4;
|
|
INSERT INTO t3 VALUES (2), (3);
|
|
ANALYZE table t1, t2, t3;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status OK
|
|
test.t2 analyze status OK
|
|
test.t3 analyze status OK
|
|
SELECT COUNT(*) FROM t3;
|
|
COUNT(*)
|
|
15972
|
|
EXPLAIN SELECT SQL_CALC_FOUND_ROWS * FROM t1 LEFT JOIN t2 ON t1.a=t2.a
|
|
LEFT JOIN t3 ON t2.b=t3.b;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
|
|
1 SIMPLE t2 ref idx idx 5 test.t1.a 1
|
|
1 SIMPLE t3 ref idx idx 5 test.t2.b 1 Using index
|
|
FLUSH STATUS ;
|
|
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LEFT JOIN t2 ON t1.a=t2.a
|
|
LEFT JOIN t3 ON t2.b=t3.b;
|
|
a a b b
|
|
1 1 1 NULL
|
|
2 NULL NULL NULL
|
|
3 3 1 NULL
|
|
4 NULL NULL NULL
|
|
SELECT FOUND_ROWS();
|
|
FOUND_ROWS()
|
|
4
|
|
SHOW STATUS LIKE "handler_read%";
|
|
Variable_name Value
|
|
Handler_read_first 0
|
|
Handler_read_key 6
|
|
Handler_read_next 2
|
|
Handler_read_prev 0
|
|
Handler_read_rnd 0
|
|
Handler_read_rnd_next 5
|
|
DROP TABLE t1,t2,t3,t4;
|