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Postgres LISTEN/NOTIFY does not scale

(www.recall.ai)
570 points davidgu | 1 comments | 07 Jul 25 14:05 UTC | HN request time: 0.388s | source
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andrewstuart ◴[10 Jul 25 20:54 UTC] No.44525490[source]▶
There’s lots of ways to invoke NOTIFY without doing it from with the transaction doing the work.

The post author is too focused on using NOTIFY in only one way.

This post fails to explain WHY they are sending a NOTIFY. Not much use telling us what doesn’t work without telling us the actual business goal.

It’s crazy to send a notify for every transaction, they should be debounced/grouped.

The point of a NOTIFY is to let some other system know something has changed. Don’t do it every transaction.

replies(3): >>44525723 #>>44525784 #>>44526191 #
1. thom ◴[10 Jul 25 22:06 UTC] No.44526191[source]▶
Yeah, the way I've always used LISTEN/NOTIFY is just to tell some pool of workers that they should wake up and check some transactional outbox for new work. False positives are basically harmless and therefore don't need to be transactional. If you're sending sophisticated messages with NOTIFY (which is a reasonable thing to think you can do) you're probably headed for pain at some point.