Create some forums and posts in those Run php admin/cli/scheduled_task.php --execute=\\mod_forum\\task\\cron_task --showsql Observe SQL output something like: SELECT pg_advisory_unlock($ 1 , $ 2 ) AS unlocked [array ( 0 => - 831030149 , 1 => 2127591 , )] -------------------------------- Query took: 0.00011992454528809 seconds. -------------------------------- Run php admin/cli/scheduled_task.php --execute=\\mod_forum\\task\\cron_task Check the SQL output now doesn't display any SQL query Edit config.php and set $CFG->showcronsql = true; run php admin/cli/scheduled_task.php --execute=\\mod_forum\\task\\cron_task Check that you still can see SQL output