1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
drop table if exists t1,t2,t3;
flush status;
set autocommit=0;
create table t1 (a int not null) engine=innodb;
insert into t1 values (1),(2),(3);
select * from t1;
a
1
2
3
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 0
drop table t1;
commit;
set autocommit=1;
begin;
create table t1 (a int not null) engine=innodb;
insert into t1 values (1),(2),(3);
select * from t1;
a
1
2
3
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 1
drop table t1;
commit;
create table t1 (a int not null) engine=innodb;
create table t2 (a int not null) engine=innodb;
create table t3 (a int not null) engine=innodb;
insert into t1 values (1),(2);
insert into t2 values (1),(2);
insert into t3 values (1),(2);
select * from t1;
a
1
2
select * from t2;
a
1
2
select * from t3;
a
1
2
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 3
show status like "Qcache_hits";
Variable_name Value
Qcache_hits 0
begin;
select * from t1;
a
1
2
select * from t2;
a
1
2
select * from t3;
a
1
2
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 3
show status like "Qcache_hits";
Variable_name Value
Qcache_hits 3
insert into t1 values (3);
insert into t2 values (3);
insert into t1 values (4);
select * from t1;
a
1
2
3
4
select * from t2;
a
1
2
3
select * from t3;
a
1
2
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 1
show status like "Qcache_hits";
Variable_name Value
Qcache_hits 4
commit;
show status like "Qcache_queries_in_cache";
Variable_name Value
Qcache_queries_in_cache 1
drop table t3,t2,t1;
CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY (id)) ENGINE=InnoDB;
select count(*) from t1;
count(*)
0
insert into t1 (id) values (0);
select count(*) from t1;
count(*)
1
drop table t1;
set GLOBAL query_cache_size=1355776;
CREATE TABLE t1 ( id int(10) NOT NULL auto_increment, a varchar(25) default NULL, PRIMARY KEY (id), UNIQUE KEY a (a)) ENGINE=innodb;
CREATE TABLE t2 ( id int(10) NOT NULL auto_increment, b varchar(25) default NULL, PRIMARY KEY (id), UNIQUE KEY b (b)) ENGINE=innodb;
CREATE TABLE t3 ( id int(10) NOT NULL auto_increment, t1_id int(10) NOT NULL default '0', t2_id int(10) NOT NULL default '0', state int(11) default NULL, PRIMARY KEY (id), UNIQUE KEY t1_id (t1_id,t2_id), KEY t2_id (t2_id,t1_id), CONSTRAINT `t3_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`), CONSTRAINT `t3_ibfk_2` FOREIGN KEY (`t2_id`) REFERENCES `t2` (`id`)) ENGINE=innodb;
INSERT INTO t1 VALUES (1,'me');
INSERT INTO t2 VALUES (1,'you');
INSERT INTO t3 VALUES (2,1,1,2);
delete from t3 where t1_id = 1 and t2_id = 1;
select t1.* from t1, t2, t3 where t3.state & 1 = 0 and t3.t1_id = t1.id and t3.t2_id = t2.id and t1.id = 1 order by t1.a asc;
id a
begin;
insert into t3 VALUES ( NULL, 1, 1, 2 );
insert into t3 VALUES ( NULL, 1, 1, 2 );
ERROR 23000: Duplicate entry '1-1' for key 2
commit;
select t1.* from t1, t2, t3 where t3.state & 1 = 0 and t3.t1_id = t1.id and t3.t2_id = t2.id and t1.id = 1 order by t1.a asc;
id a
1 me
drop table t3,t2,t1;
|
