drop table if exists t1, t2, t3, t4, t5, t6, t7, t8;
CREATE TABLE t1 (
a int NOT NULL PRIMARY KEY,
b int not null,
c int,
UNIQUE ib(b)
) engine=ndbcluster;
insert t1 values(1, 2, 3), (2, 3, 5), (3, 4, 6), (4, 5, 8), (5,6, 2), (6,7, 2);
select * from t1 order by b;
a b c
1 2 3
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
select * from t1 where b = 4 order by b;
a b c
3 4 6
insert into t1 values(7,8,3);
select * from t1 where b = 4 order by a;
a b c
3 4 6
insert into t1 values(8, 2, 3);
ERROR 23000: Duplicate entry '2' for key 'ib'
select * from t1 order by a;
a b c
1 2 3
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
7 8 3
delete from t1 where a = 1;
insert into t1 values(8, 2, 3);
select * from t1 order by a;
a b c
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
7 8 3
8 2 3
alter table t1 drop index ib;
insert into t1 values(1, 2, 3);
create unique index ib on t1(b);
ERROR 23000: Can't write, because of unique constraint, to table 't1'
drop table t1;
CREATE TABLE t1 (
a int unsigned NOT NULL PRIMARY KEY,
b int unsigned,
c int unsigned,
UNIQUE bc(b,c)
) engine = ndb;
insert into t1 values(1,1,1),(2,NULL,2),(3,NULL,NULL),(4,4,NULL);
select * from t1 use index (bc) where b IS NULL order by a;
a b c
2 NULL 2
3 NULL NULL
select * from t1 use index (bc)order by a;
a b c
1 1 1
2 NULL 2
3 NULL NULL
4 4 NULL
select * from t1 use index (bc) order by a;
a b c
1 1 1
2 NULL 2
3 NULL NULL
4 4 NULL
select * from t1 use index (PRIMARY) where b IS NULL order by a;
a b c
2 NULL 2
3 NULL NULL
select * from t1 use index (bc) where b IS NULL order by a;
a b c
2 NULL 2
3 NULL NULL
select * from t1 use index (bc) where b IS NULL and c IS NULL order by a;
a b c
3 NULL NULL
select * from t1 use index (bc) where b IS NULL and c = 2 order by a;
a b c
2 NULL 2
select * from t1 use index (bc) where b < 4 order by a;
a b c
1 1 1
select * from t1 use index (bc) where b IS NOT NULL order by a;
a b c
1 1 1
4 4 NULL
insert into t1 values(5,1,1);
ERROR 23000: Duplicate entry '1-1' for key 'bc'
drop table t1;
CREATE TABLE t2 (
a int unsigned NOT NULL PRIMARY KEY,
b int unsigned not null,
c int unsigned not null,
UNIQUE (b, c) USING HASH
) engine=ndbcluster;
insert t2 values(1, 2, 3), (2, 3, 5), (3, 4, 6), (4, 5, 8), (5,6, 2), (6,7, 2);
select * from t2 where a = 3;
a b c
3 4 6
select * from t2 where b = 4;
a b c
3 4 6
select * from t2 where c = 6;
a b c
3 4 6
insert into t2 values(7,8,3);
select * from t2 where b = 4 order by a;
a b c
3 4 6
insert into t2 values(8, 2, 3);
ERROR 23000: Duplicate entry '2-3' for key 'b'
select * from t2 order by a;
a b c
1 2 3
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
7 8 3
delete from t2 where a = 1;
insert into t2 values(8, 2, 3);
select * from t2 order by a;
a b c
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
7 8 3
8 2 3
create unique index bi using hash on t2(b);
insert into t2 values(9, 3, 1);
ERROR 23000: Duplicate entry '3' for key 'bi'
alter table t2 drop index bi;
insert into t2 values(9, 3, 1);
select * from t2 order by a;
a b c
2 3 5
3 4 6
4 5 8
5 6 2
6 7 2
7 8 3
8 2 3
9 3 1
drop table t2;
CREATE TABLE t2 (
a int unsigned NOT NULL PRIMARY KEY,
b int unsigned not null,
c int unsigned,
UNIQUE (b, c) USING HASH
) engine=ndbcluster;
Warnings:
Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
insert t2 values(1,1,NULL),(2,2,2),(3,3,NULL),(4,4,4),(5,5,NULL),(6,6,6),(7,7,NULL),(8,3,NULL),(9,3,NULL);
select * from t2 where c IS NULL order by a;
a b c
1 1 NULL
3 3 NULL
5 5 NULL
7 7 NULL
8 3 NULL
9 3 NULL
select * from t2 where b = 3 AND c IS NULL order by a;
a b c
3 3 NULL
8 3 NULL
9 3 NULL
select * from t2 where (b = 3 OR b = 5) AND c IS NULL order by a;
a b c
3 3 NULL
5 5 NULL
8 3 NULL
9 3 NULL
set @old_os = @@session.optimizer_switch;
set optimizer_switch = 'engine_condition_pushdown=on';
explain select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY,b b 9 NULL 2 Using where with pushed condition; Using filesort
select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
a b c
3 3 NULL
5 5 NULL
8 3 NULL
set optimizer_switch = @old_os;
drop table t2;
CREATE TABLE t3 (
a int unsigned NOT NULL,
b int unsigned not null,
c int unsigned,
PRIMARY KEY (a, b) USING HASH
) engine=ndbcluster;
insert t3 values(1, 2, 3), (2, 3, 5), (3, 4, 6), (4, 5, 8), (5,6, 2), (6,7, 2);
select * from t3 where a = 3;
a b c
3 4 6
select * from t3 where b = 4;
a b c
3 4 6
select * from t3 where c = 6;
a b c
3 4 6
insert into t3 values(7,8,3);
select * from t3 where b = 4 order by a;
a b c
3 4 6
drop table t3;
CREATE TABLE t1 (
pk int NOT NULL PRIMARY KEY,
a int unsigned,
UNIQUE KEY (a)
) engine=ndbcluster;
insert into t1 values (-1,NULL), (0,0), (1,NULL),(2,2),(3,NULL),(4,4);
select * from t1 order by pk;
pk a
-1 NULL
0 0
1 NULL
2 2
3 NULL
4 4
insert into t1 values (5,0);
ERROR 23000: Duplicate entry '0' for key 'a'
select * from t1 order by pk;
pk a
-1 NULL
0 0
1 NULL
2 2
3 NULL
4 4
delete from t1 where a = 0;
insert into t1 values (5,0);
select * from t1 order by pk;
pk a
-1 NULL
1 NULL
2 2
3 NULL
4 4
5 0
CREATE TABLE t2 (
pk int NOT NULL PRIMARY KEY,
a int unsigned,
b tinyint NOT NULL,
c VARCHAR(10),
UNIQUE KEY si(a, c)
) engine=ndbcluster;
insert into t2 values (-1,1,17,NULL),(0,NULL,18,NULL),(1,3,19,'abc');
select * from t2 order by pk;
pk a b c
-1 1 17 NULL
0 NULL 18 NULL
1 3 19 abc
insert into t2 values(2,3,19,'abc');
ERROR 23000: Duplicate entry '3-abc' for key 'si'
select * from t2 order by pk;
pk a b c
-1 1 17 NULL
0 NULL 18 NULL
1 3 19 abc
delete from t2 where c IS NOT NULL;
insert into t2 values(2,3,19,'abc');
select * from t2 order by pk;
pk a b c
-1 1 17 NULL
0 NULL 18 NULL
2 3 19 abc
drop table t1, t2;
CREATE TABLE t1 (
cid smallint(5) unsigned NOT NULL default '0',
cv varchar(250) NOT NULL default '',
PRIMARY KEY (cid),
UNIQUE KEY cv (cv)
) engine=ndbcluster;
INSERT INTO t1 VALUES (8,'dummy');
CREATE TABLE t2 (
cid bigint(20) unsigned NOT NULL auto_increment,
cap varchar(255) NOT NULL default '',
PRIMARY KEY (cid),
UNIQUE KEY (cid, cap)
) engine=ndbcluster;
INSERT INTO t2 VALUES (NULL,'another dummy');
CREATE TABLE t3 (
gid bigint(20) unsigned NOT NULL auto_increment,
gn varchar(255) NOT NULL default '',
must tinyint(4) default NULL,
PRIMARY KEY (gid)
) engine=ndbcluster;
INSERT INTO t3 VALUES (1,'V1',NULL);
CREATE TABLE t4 (
uid bigint(20) unsigned NOT NULL default '0',
gid bigint(20) unsigned NOT NULL,
rid bigint(20) unsigned NOT NULL,
cid bigint(20) unsigned NOT NULL,
UNIQUE KEY m (uid,gid,rid,cid)
) engine=ndbcluster;
INSERT INTO t4 VALUES (1,1,2,4);
INSERT INTO t4 VALUES (1,1,2,3);
INSERT INTO t4 VALUES (1,1,5,7);
INSERT INTO t4 VALUES (1,1,10,8);
CREATE TABLE t5 (
rid bigint(20) unsigned NOT NULL auto_increment,
rl varchar(255) NOT NULL default '',
PRIMARY KEY (rid)
) engine=ndbcluster;
CREATE TABLE t6 (
uid bigint(20) unsigned NOT NULL auto_increment,
un varchar(250) NOT NULL default '',
uc smallint(5) unsigned NOT NULL default '0',
PRIMARY KEY (uid),
UNIQUE KEY nc (un,uc)
) engine=ndbcluster;
INSERT INTO t6 VALUES (1,'test',8);
INSERT INTO t6 VALUES (2,'test2',9);
INSERT INTO t6 VALUES (3,'tre',3);
CREATE TABLE t7 (
mid bigint(20) unsigned NOT NULL PRIMARY KEY,
uid bigint(20) unsigned NOT NULL default '0',
gid bigint(20) unsigned NOT NULL,
rid bigint(20) unsigned NOT NULL,
cid bigint(20) unsigned NOT NULL,
UNIQUE KEY m (uid,gid,rid,cid)
) engine=ndbcluster;
INSERT INTO t7 VALUES(1, 1, 1, 1, 1);
INSERT INTO t7 VALUES(2, 2, 1, 1, 1);
INSERT INTO t7 VALUES(3, 3, 1, 1, 1);
INSERT INTO t7 VALUES(4, 4, 1, 1, 1);
INSERT INTO t7 VALUES(5, 5, 1, 1, 1);
INSERT INTO t7 VALUES(6, 1, 1, 1, 6);
INSERT INTO t7 VALUES(7, 2, 1, 1, 7);
INSERT INTO t7 VALUES(8, 3, 1, 1, 8);
INSERT INTO t7 VALUES(9, 4, 1, 1, 9);
INSERT INTO t7 VALUES(10, 5, 1, 1, 10);
select * from t1 where cv = 'dummy';
cid cv
8 dummy
select * from t1 where cv = 'test';
cid cv
select * from t2 where cap = 'another dummy';
cid cap
1 another dummy
select * from t4 where uid = 1 and gid=1 and rid=2 and cid=4;
uid gid rid cid
1 1 2 4
select * from t4 where uid = 1 and gid=1 and rid=1 and cid=4;
uid gid rid cid
select * from t4 where uid = 1 order by cid;
uid gid rid cid
1 1 2 3
1 1 2 4
1 1 5 7
1 1 10 8
select * from t4 where rid = 2 order by cid;
uid gid rid cid
1 1 2 3
1 1 2 4
select * from t6 where un='test' and uc=8;
uid un uc
1 test 8
select * from t6 where un='test' and uc=7;
uid un uc
select * from t6 where un='test';
uid un uc
1 test 8
select * from t7 where mid = 8;
mid uid gid rid cid
8 3 1 1 8
select * from t7 where uid = 8;
mid uid gid rid cid
select * from t7 where uid = 1 order by mid;
mid uid gid rid cid
1 1 1 1 1
6 1 1 1 6
select * from t7 where uid = 4 order by mid;
mid uid gid rid cid
4 4 1 1 1
9 4 1 1 9
select * from t7 where gid = 4;
mid uid gid rid cid
select * from t7 where gid = 1 order by mid;
mid uid gid rid cid
1 1 1 1 1
2 2 1 1 1
3 3 1 1 1
4 4 1 1 1
5 5 1 1 1
6 1 1 1 6
7 2 1 1 7
8 3 1 1 8
9 4 1 1 9
10 5 1 1 10
select * from t7 where cid = 4;
mid uid gid rid cid
select * from t7 where cid = 8;
mid uid gid rid cid
8 3 1 1 8
select * from t4 where uid = 1 and gid=1 and rid=2 and cid=4;
uid gid rid cid
1 1 2 4
select * from t4 where uid = 1 and gid=1 and rid=1 and cid=4;
uid gid rid cid
select * from t4 where uid = 1 order by gid,cid;
uid gid rid cid
1 1 2 3
1 1 2 4
1 1 5 7
1 1 10 8
1 1 5 12
1 2 5 12
1 3 9 11
1 3 5 12
1 4 5 12
1 5 5 12
1 6 5 12
1 7 5 12
1 8 5 12
1 9 5 12
1 10 5 12
1 11 5 12
1 12 5 12
1 13 5 12
1 14 5 12
1 15 5 12
1 16 5 12
1 17 5 12
1 18 5 12
1 19 5 12
1 20 5 12
1 21 5 12
1 22 5 12
1 23 5 12
1 24 5 12
1 25 5 12
1 26 5 12
1 27 5 12
1 28 5 12
1 29 5 12
1 30 5 12
1 31 5 12
1 32 5 12
1 33 5 12
1 34 5 12
1 35 5 12
1 36 5 12
1 37 5 12
1 38 5 12
1 39 5 12
1 40 5 12
1 41 5 12
1 42 5 12
1 43 5 12
1 44 5 12
1 45 5 12
1 46 5 12
1 47 5 12
1 48 5 12
1 49 5 12
1 50 5 12
1 51 5 12
1 52 5 12
1 53 5 12
1 54 5 12
1 55 5 12
1 56 5 12
1 57 5 12
1 58 5 12
1 59 5 12
1 60 5 12
1 61 5 12
1 62 5 12
1 63 5 12
1 64 5 12
1 65 5 12
1 66 5 12
1 67 5 12
1 68 5 12
1 69 5 12
1 70 5 12
1 71 5 12
1 72 5 12
1 73 5 12
1 74 5 12
1 75 5 12
1 76 5 12
1 77 5 12
1 78 5 12
1 79 5 12
1 80 5 12
1 81 5 12
1 82 5 12
1 83 5 12
1 84 5 12
1 85 5 12
1 86 5 12
1 87 5 12
1 88 5 12
1 89 5 12
1 90 5 12
1 91 5 12
1 92 5 12
1 93 5 12
1 94 5 12
1 95 5 12
1 96 5 12
1 97 5 12
1 98 5 12
1 99 5 12
1 100 5 12
select * from t4 where uid = 1 order by gid,cid;
uid gid rid cid
1 1 2 3
1 1 2 4
1 1 5 7
1 1 10 8
1 1 5 12
1 2 5 12
1 3 9 11
1 3 5 12
1 4 5 12
1 5 5 12
1 6 5 12
1 7 5 12
1 8 5 12
1 9 5 12
1 10 5 12
1 11 5 12
1 12 5 12
1 13 5 12
1 14 5 12
1 15 5 12
1 16 5 12
1 17 5 12
1 18 5 12
1 19 5 12
1 20 5 12
1 21 5 12
1 22 5 12
1 23 5 12
1 24 5 12
1 25 5 12
1 26 5 12
1 27 5 12
1 28 5 12
1 29 5 12
1 30 5 12
1 31 5 12
1 32 5 12
1 33 5 12
1 34 5 12
1 35 5 12
1 36 5 12
1 37 5 12
1 38 5 12
1 39 5 12
1 40 5 12
1 41 5 12
1 42 5 12
1 43 5 12
1 44 5 12
1 45 5 12
1 46 5 12
1 47 5 12
1 48 5 12
1 49 5 12
1 50 5 12
1 51 5 12
1 52 5 12
1 53 5 12
1 54 5 12
1 55 5 12
1 56 5 12
1 57 5 12
1 58 5 12
1 59 5 12
1 60 5 12
1 61 5 12
1 62 5 12
1 63 5 12
1 64 5 12
1 65 5 12
1 66 5 12
1 67 5 12
1 68 5 12
1 69 5 12
1 70 5 12
1 71 5 12
1 72 5 12
1 73 5 12
1 74 5 12
1 75 5 12
1 76 5 12
1 77 5 12
1 78 5 12
1 79 5 12
1 80 5 12
1 81 5 12
1 82 5 12
1 83 5 12
1 84 5 12
1 85 5 12
1 86 5 12
1 87 5 12
1 88 5 12
1 89 5 12
1 90 5 12
1 91 5 12
1 92 5 12
1 93 5 12
1 94 5 12
1 95 5 12
1 96 5 12
1 97 5 12
1 98 5 12
1 99 5 12
1 100 5 12
select * from t4 where rid = 2 order by cid;
uid gid rid cid
1 1 2 3
1 1 2 4
drop table t1,t2,t3,t4,t5,t6,t7;
CREATE TABLE t1 (
a int unsigned NOT NULL PRIMARY KEY,
b int unsigned,
c int unsigned,
UNIQUE bc(b,c) ) engine = ndb;
insert into t1 values(1,1,1),(2,NULL,2),(3,NULL,NULL),(4,4,NULL);
select * from t1 where b=1 and c=1;
a b c
1 1 1
select * from t1 where b is null and c is null;
a b c
3 NULL NULL
select * from t1 where b is null and c = 2;
a b c
2 NULL 2
select * from t1 where b = 4 and c is null;
a b c
4 4 NULL
create table t8 as
select * from t1 where (b = 1 and c = 1)
or (b is null and c is null)
or (b is null and c = 2)
or (b = 4 and c is null);
select * from t8 order by a;
a b c
1 1 1
2 NULL 2
3 NULL NULL
4 4 NULL
select * from t1 order by a;
a b c
1 1 1
2 NULL 2
3 NULL NULL
4 4 NULL
drop table t1, t8;
create table t1(
id integer not null auto_increment,
month integer not null,
year integer not null,
code varchar( 2) not null,
primary key ( id),
unique idx_t1( month, code, year)
) engine=ndb;
INSERT INTO t1 (month, year, code) VALUES (4,2004,'12');
INSERT INTO t1 (month, year, code) VALUES (5,2004,'12');
select * from t1 where code = '12' and month = 4 and year = 2004 ;
id month year code
1 4 2004 12
drop table t1;
create table t1 (a int primary key, b varchar(1000) not null, unique key (b))
engine=ndb charset=utf8;
insert into t1 values (1, repeat(_utf8 0xe288ab6474, 200));
insert into t1 values (2, repeat(_utf8 0xe288ab6474, 200));
ERROR 23000: Duplicate entry '\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bdt\222Bd' for key 'b'
select a, sha1(b) from t1;
a sha1(b)
1 08f5d02c8b8bc244f275bdfc22c42c5cab0d9d7d
drop table t1;
create table t1(id int not null) engine = NDB;
alter table t1 add constraint uk_test unique (id) using hash;
drop table t1;
CREATE TABLE t1 (
pk0 INT,
pk1 VARCHAR(100),
col0 INT NOT NULL,
PRIMARY KEY(pk0, pk1),
UNIQUE (col0) USING HASH
) engine = ndb;
CREATE TABLE t2 (
pk0 VARCHAR(100),
pk1 INT,
col0 INT NOT NULL,
PRIMARY KEY(pk0, pk1),
UNIQUE (col0) USING HASH
) engine = ndb;
drop table t1, t2;
CREATE LOGFILE GROUP lg1
ADD UNDOFILE 'undofile.dat'
INITIAL_SIZE 8M
UNDO_BUFFER_SIZE = 1M engine=ndb;
CREATE TABLESPACE ts1
ADD DATAFILE 'datafile.dat'
USE LOGFILE GROUP lg1
INITIAL_SIZE 32M
ENGINE NDB;
use test;
create table t1 (pk int primary key, un int, data varchar(500) storage disk) tablespace ts1 engine=ndb;
insert into t1 values
(1,1,repeat('B', 500)),
(2,2,repeat('B', 500)),
(3,3,repeat('B', 500)),
(4,4,repeat('B', 500)),
(5,5,repeat('B', 500)),
(6,6,repeat('B', 500)),
(7,7,repeat('B', 500)),
(8,8,repeat('B', 500)),
(9,9,repeat('B', 500)),
(10,10,repeat('B', 500)),
(11,11,repeat('B', 500)),
(12,12,repeat('B', 500)),
(13,13,repeat('B', 500)),
(14,14,repeat('B', 500)),
(15,15,repeat('B', 500));
alter table t1 add unique(un);
drop table t1;
alter tablespace ts1 drop datafile 'datafile.dat' engine=ndb;
drop tablespace ts1 engine=ndb;
drop logfile group lg1 engine=ndb;
# bug#57032
create table t1 (
a int not null,
b int,
primary key using hash (a),
unique key using hash (b)
)
engine ndb;
Warnings:
Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
insert into t1 values
(0,0),(1,1),(2,2),(3,3),(4,4),
(5,null),(6,null),(7,null),(8,null),(9,null);
set optimizer_switch = 'engine_condition_pushdown=off';
select a from t1 where b is not null order by a;
a
0
1
2
3
4
select a from t1 where b is null order by a;
a
5
6
7
8
9
set optimizer_switch = 'engine_condition_pushdown=on';
select a from t1 where b is not null order by a;
a
0
1
2
3
4
select a from t1 where b is null order by a;
a
5
6
7
8
9
set optimizer_switch = @old_os;
drop table t1;
create table t1 (
a int not null,
b int,
c int,
primary key using hash (a),
unique key using hash (b,c)
)
engine ndb;
Warnings:
Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
insert into t1 values
(0,0,0),(1,1,1),(2,2,1),(3,3,1),(4,4,2),
(5,null,0),(6,null,1),(7,null,1),(8,null,1),(9,null,2),
(10,0,null),(11,1,null),(12,1,null),(13,1,null),(14,2,null),
(15,null,null),(16,null,null),(17,null,null),(18,null,null),(19,null,null);
set optimizer_switch = 'engine_condition_pushdown=off';
select a from t1 where b is not null and c = 1 order by a;
a
1
2
3
select a from t1 where b is null and c = 1 order by a;
a
6
7
8
select a from t1 where b = 1 and c is null order by a;
a
11
12
13
select a from t1 where b is null and c is null order by a;
a
15
16
17
18
19
select a from t1 where b is not null and c is null order by a;
a
10
11
12
13
14
select a from t1 where b is null and c is not null order by a;
a
5
6
7
8
9
select a from t1 where b is not null and c is not null order by a;
a
0
1
2
3
4
set optimizer_switch = 'engine_condition_pushdown=on';
select a from t1 where b is not null and c = 1 order by a;
a
1
2
3
select a from t1 where b is null and c = 1 order by a;
a
6
7
8
select a from t1 where b = 1 and c is null order by a;
a
11
12
13
select a from t1 where b is null and c is null order by a;
a
15
16
17
18
19
select a from t1 where b is not null and c is null order by a;
a
10
11
12
13
14
select a from t1 where b is null and c is not null order by a;
a
5
6
7
8
9
select a from t1 where b is not null and c is not null order by a;
a
0
1
2
3
4
set optimizer_switch = @old_os;
drop table t1;
create table t1 (pk int primary key, a int) engine=ndb;
create table t2 (pk int primary key, uq int, a int,
unique key ix(uq,a) USING HASH) engine=ndb;
Warnings:
Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
insert into t2 values
(0,0,0), (1,1,0), (2,2,0), (3,3,0), (4,4,0),
(5,5,1), (6,6,1), (7,7,1), (8,8,1), (9,9,1);
insert into t1
select
t1.pk + t2.pk*10 + t3.pk*100 + t4.pk*1000, t1.a
from
t2 as t1, t2 as t2, t2 as t3, t2 as t4;
explain
SELECT STRAIGHT_JOIN count(*) FROM
t1 JOIN t2 ON t2.a=t1.a where t2.uq IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 10000 Using where with pushed condition
1 SIMPLE t2 ref ix ix 10 const,test.t1.a 1 Using where with pushed condition
SELECT STRAIGHT_JOIN count(*) FROM
t1 JOIN t2 ON t2.a=t1.a where t2.uq IS NULL;
count(*)
0
drop table t1,t2;