1SET @start_global_value = @@global.max_join_size;
2SELECT @start_global_value;
3@start_global_value
418446744073709551615
5select @@global.max_join_size;
6@@global.max_join_size
718446744073709551615
8select @@session.max_join_size;
9@@session.max_join_size
1018446744073709551615
11show global variables like 'max_join_size';
12Variable_name	Value
13max_join_size	18446744073709551615
14show session variables like 'max_join_size';
15Variable_name	Value
16max_join_size	18446744073709551615
17select * from information_schema.global_variables where variable_name='max_join_size';
18VARIABLE_NAME	VARIABLE_VALUE
19MAX_JOIN_SIZE	18446744073709551615
20select * from information_schema.session_variables where variable_name='max_join_size';
21VARIABLE_NAME	VARIABLE_VALUE
22MAX_JOIN_SIZE	18446744073709551615
23set global max_join_size=10;
24set session max_join_size=20;
25select @@global.max_join_size;
26@@global.max_join_size
2710
28select @@session.max_join_size;
29@@session.max_join_size
3020
31show global variables like 'max_join_size';
32Variable_name	Value
33max_join_size	10
34show session variables like 'max_join_size';
35Variable_name	Value
36max_join_size	20
37select * from information_schema.global_variables where variable_name='max_join_size';
38VARIABLE_NAME	VARIABLE_VALUE
39MAX_JOIN_SIZE	10
40select * from information_schema.session_variables where variable_name='max_join_size';
41VARIABLE_NAME	VARIABLE_VALUE
42MAX_JOIN_SIZE	20
43set global max_join_size=1.1;
44ERROR 42000: Incorrect argument type to variable 'max_join_size'
45set global max_join_size=1e1;
46ERROR 42000: Incorrect argument type to variable 'max_join_size'
47set global max_join_size="foo";
48ERROR 42000: Incorrect argument type to variable 'max_join_size'
49select @@sql_big_selects;
50@@sql_big_selects
510
52set max_join_size=cast(-1 as unsigned int);
53Warnings:
54Note	1105	Cast to unsigned converted negative integer to it's positive complement
55select @@sql_big_selects;
56@@sql_big_selects
571
58set max_join_size=100;
59select @@sql_big_selects;
60@@sql_big_selects
610
62SET @@global.max_join_size = @start_global_value;
63SELECT @@global.max_join_size;
64@@global.max_join_size
6518446744073709551615
66