select @@global.debug_no_thread_alarm;
@@global.debug_no_thread_alarm
0
select @@session.debug_no_thread_alarm;
ERROR HY000: Variable 'debug_no_thread_alarm' is a GLOBAL variable
show global variables like 'debug_no_thread_alarm';
Variable_name	Value
debug_no_thread_alarm	OFF
show session variables like 'debug_no_thread_alarm';
Variable_name	Value
debug_no_thread_alarm	OFF
select * from information_schema.global_variables where variable_name='debug_no_thread_alarm';
VARIABLE_NAME	VARIABLE_VALUE
DEBUG_NO_THREAD_ALARM	OFF
select * from information_schema.session_variables where variable_name='debug_no_thread_alarm';
VARIABLE_NAME	VARIABLE_VALUE
DEBUG_NO_THREAD_ALARM	OFF
set global debug_no_thread_alarm=1;
ERROR HY000: Variable 'debug_no_thread_alarm' is a read only variable
set session debug_no_thread_alarm=1;
ERROR HY000: Variable 'debug_no_thread_alarm' is a read only variable