SET @start_global_value = @@global.relay_log_recovery;
SELECT @start_global_value;
@start_global_value
0
select @@global.relay_log_recovery;
@@global.relay_log_recovery
0
select @@session.relay_log_recovery;
ERROR HY000: Variable 'relay_log_recovery' is a GLOBAL variable
show global variables like 'relay_log_recovery';
Variable_name	Value
relay_log_recovery	OFF
show session variables like 'relay_log_recovery';
Variable_name	Value
relay_log_recovery	OFF
select * from information_schema.global_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	OFF
select * from information_schema.session_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	OFF
set global relay_log_recovery=1;
select @@global.relay_log_recovery;
@@global.relay_log_recovery
1
select * from information_schema.global_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	ON
select * from information_schema.session_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	ON
set global relay_log_recovery=OFF;
select @@global.relay_log_recovery;
@@global.relay_log_recovery
0
select * from information_schema.global_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	OFF
select * from information_schema.session_variables where variable_name='relay_log_recovery';
VARIABLE_NAME	VARIABLE_VALUE
RELAY_LOG_RECOVERY	OFF
set session relay_log_recovery=1;
ERROR HY000: Variable 'relay_log_recovery' is a GLOBAL variable and should be set with SET GLOBAL
set global relay_log_recovery=1.1;
ERROR 42000: Incorrect argument type to variable 'relay_log_recovery'
set global relay_log_recovery=1e1;
ERROR 42000: Incorrect argument type to variable 'relay_log_recovery'
set global relay_log_recovery="foo";
ERROR 42000: Variable 'relay_log_recovery' can't be set to the value of 'foo'
SET @@global.relay_log_recovery = @start_global_value;
SELECT @@global.relay_log_recovery;
@@global.relay_log_recovery
0