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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: 0s | source
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doc_manhat ◴[10 Jul 25 22:13 UTC] No.44526261[source]▶
Got up to the TL;DR paragraph. This was a major red flag given the initial presentation of the discovery of a bottleneck:

''' When a NOTIFY query is issued during a transaction, it acquires a global lock on the entire database (ref) during the commit phase of the transaction, effectively serializing all commits. '''

Am I missing something - this seems like something the original authors of the system should have done due diligence on before implementing a write heavy work load.

replies(3): >>44526339 #>>44528757 #>>44529143 #
1. kccqzy ◴[10 Jul 25 22:21 UTC] No.44526339[source]▶
I think it's just difficult to predict how heavy is heavy enough to make this a problem. FWIW I had worked at a startup with a much more primitive data storage system where serialized commits were actually totally fine. The startup never outgrew that bottleneck.