SET @start_global_value = @@global.gtid_executed;
SELECT @start_global_value;
@start_global_value

select @@global.gtid_executed;
@@global.gtid_executed

select @@session.gtid_executed;
@@session.gtid_executed

show global variables like 'gtid_executed';
Variable_name	Value
gtid_executed	
show session variables like 'gtid_executed';
Variable_name	Value
gtid_executed	
select * from information_schema.global_variables where variable_name='gtid_executed';
VARIABLE_NAME	VARIABLE_VALUE
GTID_EXECUTED	
select * from information_schema.session_variables where variable_name='gtid_executed';
VARIABLE_NAME	VARIABLE_VALUE
GTID_EXECUTED	
select @@global.gtid_executed;
@@global.gtid_executed