set session transaction_prealloc_size=1024*1024*1024*1; select @pid_temp = (select ID from information_schema.processlist) as 'TRUE'; TRUE 1 set session transaction_prealloc_size=1024*1024*1024*2; select @pid_temp = (select ID from information_schema.processlist) as 'TRUE'; TRUE 1 set session transaction_prealloc_size=1024*1024*1024*3; select @pid_temp = (select ID from information_schema.processlist) as 'TRUE'; TRUE 1 set session transaction_prealloc_size=1024*1024*1024*4; select @pid_temp = (select ID from information_schema.processlist) as 'TRUE'; TRUE 1 set session transaction_prealloc_size=1024*1024*1024*5; select @pid_temp = (select ID from information_schema.processlist) as 'TRUE'; TRUE 1