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
|
#
# test of safe selects
#
drop table if exists t1;
SET SQL_SAFE_UPDATES=1,SQL_SELECT_LIMIT=4, SQL_MAX_JOIN_SIZE=9;
create table t1 (a int auto_increment primary key, b char(20));
insert into t1 values(1,"test");
SELECT SQL_BUFFER_RESULT * from t1;
update t1 set b="a" where a=1;
delete from t1 where a=1;
insert into t1 values(1,"test"),(2,"test2");
SELECT SQL_BUFFER_RESULT * from t1;
update t1 set b="a" where a=1;
select 1 from t1,t1 as t2,t1 as t3;
# The following should give errors:
--error 1175
update t1 set b="a";
--error 1175
update t1 set b="a" where b="test";
--error 1175
delete from t1;
--error 1175
delete from t1 where b="test";
--error 1175
delete from t1 where a+0=1;
--error 1104
select 1 from t1,t1 as t2,t1 as t3,t1 as t4,t1 as t5;
# The following should be ok:
update t1 set b="a" limit 1;
update t1 set b="a" where b="b" limit 2;
delete from t1 where b="test" limit 1;
delete from t1 where a+0=1 limit 2;
# Test SQL_BIG_SELECTS
alter table t1 add key b (b);
SET MAX_JOIN_SIZE=2;
SELECT @@MAX_JOIN_SIZE, @@SQL_BIG_SELECTS;
insert into t1 values (null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a");
--error 1104
SELECT * from t1 order by a;
SET SQL_BIG_SELECTS=1;
SELECT * from t1 order by a;
SET MAX_JOIN_SIZE=2;
--error 1104
SELECT * from t1;
SET MAX_JOIN_SIZE=DEFAULT;
SELECT * from t1;
#
# Test MAX_SEEKS_FOR_KEY
#
SELECT @@MAX_SEEKS_FOR_KEY;
analyze table t1;
insert into t1 values (null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a"),(null,"a");
explain select STRAIGHT_JOIN * from t1,t1 as t2 where t1.b=t2.b;
set MAX_SEEKS_FOR_KEY=1;
explain select STRAIGHT_JOIN * from t1,t1 as t2 where t1.b=t2.b;
SET MAX_SEEKS_FOR_KEY=DEFAULT;
drop table t1;
SET SQL_SAFE_UPDATES=0,SQL_SELECT_LIMIT=DEFAULT, SQL_MAX_JOIN_SIZE=DEFAULT;
|
