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
|
SET @start_global_value = @@global.max_join_size;
SELECT @start_global_value;
@start_global_value
18446744073709551615
select @@global.max_join_size;
@@global.max_join_size
18446744073709551615
select @@session.max_join_size;
@@session.max_join_size
18446744073709551615
show global variables like 'max_join_size';
Variable_name Value
max_join_size 18446744073709551615
show session variables like 'max_join_size';
Variable_name Value
max_join_size 18446744073709551615
select * from information_schema.global_variables where variable_name='max_join_size';
VARIABLE_NAME VARIABLE_VALUE
MAX_JOIN_SIZE 18446744073709551615
select * from information_schema.session_variables where variable_name='max_join_size';
VARIABLE_NAME VARIABLE_VALUE
MAX_JOIN_SIZE 18446744073709551615
set global max_join_size=10;
set session max_join_size=20;
select @@global.max_join_size;
@@global.max_join_size
10
select @@session.max_join_size;
@@session.max_join_size
20
show global variables like 'max_join_size';
Variable_name Value
max_join_size 10
show session variables like 'max_join_size';
Variable_name Value
max_join_size 20
select * from information_schema.global_variables where variable_name='max_join_size';
VARIABLE_NAME VARIABLE_VALUE
MAX_JOIN_SIZE 10
select * from information_schema.session_variables where variable_name='max_join_size';
VARIABLE_NAME VARIABLE_VALUE
MAX_JOIN_SIZE 20
set global max_join_size=1.1;
ERROR 42000: Incorrect argument type to variable 'max_join_size'
set global max_join_size=1e1;
ERROR 42000: Incorrect argument type to variable 'max_join_size'
set global max_join_size="foo";
ERROR 42000: Incorrect argument type to variable 'max_join_size'
select @@sql_big_selects;
@@sql_big_selects
0
set max_join_size=cast(-1 as unsigned int);
Warnings:
Note 1105 Cast to unsigned converted negative integer to it's positive complement
select @@sql_big_selects;
@@sql_big_selects
1
set max_join_size=100;
select @@sql_big_selects;
@@sql_big_selects
0
SET @@global.max_join_size = @start_global_value;
SELECT @@global.max_join_size;
@@global.max_join_size
18446744073709551615
|
