SET @save_slave_parallel_max_queued= @@GLOBAL.slave_parallel_max_queued;
SELECT @@GLOBAL.slave_parallel_max_queued as 'Check default';
Check default
131072
SELECT @@SESSION.slave_parallel_max_queued  as 'no session var';
ERROR HY000: Variable 'slave_parallel_max_queued' is a GLOBAL variable
SET GLOBAL slave_parallel_max_queued= 0;
SET GLOBAL slave_parallel_max_queued= DEFAULT;
SET GLOBAL slave_parallel_max_queued= 65536;
SELECT @@GLOBAL.slave_parallel_max_queued;
@@GLOBAL.slave_parallel_max_queued
65536
SET GLOBAL slave_parallel_max_queued = @save_slave_parallel_max_queued;