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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
select * from information_schema.engines where engine='sequence';
ENGINE SEQUENCE
SUPPORT YES
COMMENT Generated tables filled with sequential values
TRANSACTIONS YES
XA YES
SAVEPOINTS YES
set sql_quote_show_create=0;
show create table seq_1_to_15_step_2;
Table Create Table
seq_1_to_15_step_2 CREATE TABLE seq_1_to_15_step_2 (
seq bigint(20) unsigned NOT NULL,
PRIMARY KEY (seq)
) ENGINE=SEQUENCE DEFAULT CHARSET=latin1
show create table seq_1_to_15_step;
ERROR 42S02: Table 'test.seq_1_to_15_step' doesn't exist
show create table seq_1_to_15_st;
ERROR 42S02: Table 'test.seq_1_to_15_st' doesn't exist
show create table seq_1_to_15;
Table Create Table
seq_1_to_15 CREATE TABLE seq_1_to_15 (
seq bigint(20) unsigned NOT NULL,
PRIMARY KEY (seq)
) ENGINE=SEQUENCE DEFAULT CHARSET=latin1
show create table seq_1_to_1;
Table Create Table
seq_1_to_1 CREATE TABLE seq_1_to_1 (
seq bigint(20) unsigned NOT NULL,
PRIMARY KEY (seq)
) ENGINE=SEQUENCE DEFAULT CHARSET=latin1
show create table seq_1_to_;
ERROR 42S02: Table 'test.seq_1_to_' doesn't exist
show create table seq_1_t;
ERROR 42S02: Table 'test.seq_1_t' doesn't exist
show create table seq_1;
ERROR 42S02: Table 'test.seq_1' doesn't exist
show create table seq_;
ERROR 42S02: Table 'test.seq_' doesn't exist
show create table se;
ERROR 42S02: Table 'test.se' doesn't exist
show create table seq_1_to_15_step_0;
ERROR HY000: Got error 140 "Wrong create options" from storage engine SEQUENCE
select * from seq_1_to_15_step_2;
seq
1
3
5
7
9
11
13
15
select * from seq_1_to_15;
seq
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
select * from seq_1_to_1;
seq
1
select * from seq_15_to_1;
seq
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
select * from seq_15_to_1_step_2;
seq
15
13
11
9
7
5
3
1
select * from seq_1_to_15_step_12345;
seq
1
select * from seq_15_to_1_step_12345;
seq
15
explain select * from seq_15_to_1_step_12345;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_15_to_1_step_12345 ALL NULL NULL NULL NULL 1
show open tables from test;
Database Table In_use Name_locked
test seq_15_to_1 0 0
test seq_15_to_1_step_12345 0 0
test seq_15_to_1_step_2 0 0
test seq_1_to_1 0 0
test seq_1_to_15 0 0
test seq_1_to_15_step_12345 0 0
test seq_1_to_15_step_2 0 0
show tables;
Tables_in_test
explain select * from seq_1_to_15_step_2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 index NULL PRIMARY 8 NULL 8 Using index
explain select * from seq_1_to_15_step_2 where seq > 4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 range PRIMARY PRIMARY 8 NULL 6 Using where; Using index
explain select * from seq_1_to_15_step_2 where seq between 4 and 9;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 range PRIMARY PRIMARY 8 NULL 3 Using where; Using index
explain select * from seq_1_to_15_step_2 where seq between 20 and 30;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
explain select * from seq_1_to_15_step_2 where seq between 4 and 6;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 range PRIMARY PRIMARY 8 NULL 1 Using where; Using index
explain select * from seq_1_to_15_step_2 where seq between 4 and 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 range PRIMARY PRIMARY 8 NULL 1 Using where; Using index
explain select * from seq_1_to_15_step_2 where seq between 4 and 4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
explain select * from seq_1_to_15_step_2 where seq between 5 and 5;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE seq_1_to_15_step_2 const PRIMARY PRIMARY 8 const 1 Using index
create table t1 (a int, aa int, b varchar(100));
insert t1 select seq, seq*seq, if (seq % 2, 'odd', 'even') from seq_1_to_20;
select * from t1;
a aa b
1 1 odd
2 4 even
3 9 odd
4 16 even
5 25 odd
6 36 even
7 49 odd
8 64 even
9 81 odd
10 100 even
11 121 odd
12 144 even
13 169 odd
14 196 even
15 225 odd
16 256 even
17 289 odd
18 324 even
19 361 odd
20 400 even
select aa, b from t1, seq_1_to_20_step_3 as seq where a=seq;
aa b
1 odd
16 even
49 odd
100 even
169 odd
256 even
361 odd
insert t1
select seq, seq*seq, if (seq % 2, 'odd', 'even') from seq_1_to_30
where seq > (select max(a) from t1);
select * from t1;
a aa b
1 1 odd
2 4 even
3 9 odd
4 16 even
5 25 odd
6 36 even
7 49 odd
8 64 even
9 81 odd
10 100 even
11 121 odd
12 144 even
13 169 odd
14 196 even
15 225 odd
16 256 even
17 289 odd
18 324 even
19 361 odd
20 400 even
21 441 odd
22 484 even
23 529 odd
24 576 even
25 625 odd
26 676 even
27 729 odd
28 784 even
29 841 odd
30 900 even
drop table t1;
select seq from seq_2_to_50 s1 where 0 not in
(select s1.seq % s2.seq from seq_2_to_50 s2 where s2.seq <= sqrt(s1.seq));
seq
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47
explain select seq from seq_2_to_50 s1 where 0 not in
(select s1.seq % s2.seq from seq_2_to_50 s2 where s2.seq <= sqrt(s1.seq));
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY s1 index NULL PRIMARY 8 NULL 49 Using where; Using index
2 DEPENDENT SUBQUERY s2 index PRIMARY PRIMARY 8 NULL 49 Using where; Using index
select year(dt) from
(select '1901-02-28' + interval seq year as dt from seq_0_to_99) as seqdt
where weekday(dt) = 0;
year(dt)
1910
1916
1921
1927
1938
1944
1949
1955
1966
1972
1977
1983
1994
2000
create table t1 (a int) engine=innodb;
reset master;
start transaction;
insert t1 select * from seq_1_to_10;
savepoint s1;
insert t1 select * from seq_11_to_20;
rollback to savepoint s1;
commit;
select count(*) from t1;
count(*)
10
show binlog events limit 2,10;
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 286 Query 1 354 BEGIN
master-bin.000001 354 Query 1 452 use test; insert t1 select * from seq_1_to_10
master-bin.000001 452 Xid 1 479 COMMIT /* xid */
drop table t1;
|