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
|
drop table if exists t1;
CREATE TABLE t1 (
STRING_DATA char(255) default NULL,
KEY string_data (STRING_DATA)
) TYPE=MyISAM;
INSERT INTO t1 VALUES ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA');
INSERT INTO t1 VALUES ('DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD');
INSERT INTO t1 VALUES ('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF');
INSERT INTO t1 VALUES ('FGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG');
INSERT INTO t1 VALUES ('HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH');
INSERT INTO t1 VALUES ('WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW');
CHECK TABLE t1;
Table Op Msg_type Msg_text
test.t1 check status OK
drop table t1;
create table t1 (a tinyint not null auto_increment, b blob not null, primary key (a));
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
repair table t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
delete from t1 where (a & 1);
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
repair table t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
drop table t1;
create table t1 (a int not null auto_increment, b int not null, primary key (a), index(b));
insert into t1 (b) values (1),(2),(2),(2),(2);
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
show index from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 PRIMARY 1 a A 5 NULL NULL BTREE
t1 1 b 1 b A 1 NULL NULL BTREE
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status Table is already up to date
show index from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 PRIMARY 1 a A 5 NULL NULL BTREE
t1 1 b 1 b A 1 NULL NULL BTREE
drop table t1;
create table t1 (a int not null, b int not null, c int not null, primary key (a),key(b)) type=myisam;
insert into t1 values (3,3,3),(1,1,1),(2,2,2),(4,4,4);
explain select * from t1 order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using filesort
explain select * from t1 order by b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using filesort
explain select * from t1 order by c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using filesort
explain select a from t1 order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 4 Using index
explain select b from t1 order by b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL b 4 NULL 4 Using index
explain select a,b from t1 order by b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using filesort
explain select a,b from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
explain select a,b,c from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4
drop table t1;
CREATE TABLE `t1` (
`post_id` mediumint(8) unsigned NOT NULL auto_increment,
`topic_id` mediumint(8) unsigned NOT NULL default '0',
`post_time` datetime NOT NULL default '0000-00-00 00:00:00',
`post_text` text NOT NULL,
`icon_url` varchar(10) NOT NULL default '',
`sign` tinyint(1) unsigned NOT NULL default '0',
`post_edit` varchar(150) NOT NULL default '',
`poster_login` varchar(35) NOT NULL default '',
`ip` varchar(15) NOT NULL default '',
PRIMARY KEY (`post_id`),
KEY `post_time` (`post_time`),
KEY `ip` (`ip`),
KEY `poster_login` (`poster_login`),
KEY `topic_id` (`topic_id`),
FULLTEXT KEY `post_text` (`post_text`)
) TYPE=MyISAM;
INSERT INTO t1 (post_text) VALUES ('ceci est un test'),('ceci est un test'),('ceci est un test'),('ceci est un test'),('ceci est un test');
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
CHECK TABLE t1;
Table Op Msg_type Msg_text
test.t1 check status OK
drop table t1;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1), (2), (3);
LOCK TABLES t1 WRITE;
INSERT INTO t1 VALUES (1), (2), (3);
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
DROP TABLE t1;
CREATE TABLE t1 (a varchar(255), b varchar(255), c varchar(255), KEY t1 (a, b, c));
Specified key was too long. Max key length is 500
CREATE TABLE t1 (a varchar(255), b varchar(255), c varchar(255));
ALTER TABLE t1 ADD INDEX t1 (a, b, c);
Specified key was too long. Max key length is 500
DROP TABLE t1;
|
