Two options of the ENABLE/DISABLE command let Simultaneous Update programmers monitor and debug PM queuing. The QUEUE DEBUG option traces both DS level and record level queuing, and thus is appropriate when the Concurrent Queued environment is in effect. The QUEUE TRACE option traces DS level queuing, and is appropriate for debugging when the Exclusive Queued environment is in effect. A third option, RECORD LOCKS, controls if access requests to a DS get queued or not.