Is the activity wrapped in a transaction? If so if worker crashes you get a connection timeout on postgresql and it rolls back the transaction and releases row

Is the activity wrapped in a transaction? If so if worker crashes you get a connection timeout on postgresql and it rolls back the transaction and releases row locks - then next select SKIP picks it up. If you want fast response with safety listen and on restart do a poll always to pick up anything that's ready that you might have missed a pub for. If you want lots of coverage do a poll every 10s - postgresql can handle it, you still get immediate response by listening to notify. If you need fancier approaches you can do a last_updated time on the job and or watch waiting on pg_stat_activity or similar etc - but all totally overkill I think - the simple approach get's pretty far (not an expert though at all).