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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. Someone ◴[11 Jul 25 07:03 UTC] No.44529143[source]▶
If “doing due diligence” involves reading the source code of a database server to verify a design, I doubt many people writing such systems do due diligence.

The documentation doesn’t mention any caveats in this direction, and they had 3 periods of downtime in 4 days, so I don’t think it’s a given that testing would have hit this problem.