1select @@global.relay_log;
2@@global.relay_log
3RELAY_LOG
4select @@session.relay_log;
5ERROR HY000: Variable 'relay_log' is a GLOBAL variable
6show global variables like 'relay_log';
7Variable_name	Value
8relay_log	RELAY_LOG
9show session variables like 'relay_log';
10Variable_name	Value
11relay_log	RELAY_LOG
12select * from information_schema.global_variables where variable_name='relay_log';
13VARIABLE_NAME	VARIABLE_VALUE
14RELAY_LOG	RELAY_LOG
15select * from information_schema.session_variables where variable_name='relay_log';
16VARIABLE_NAME	VARIABLE_VALUE
17RELAY_LOG	RELAY_LOG
18set global relay_log=1;
19ERROR HY000: Variable 'relay_log' is a read only variable
20set session relay_log=1;
21ERROR HY000: Variable 'relay_log' is a read only variable
22