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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: 0.399s | source
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polote ◴[10 Jul 25 20:38 UTC] No.44525307[source]▶
Rls and triggers dont scale either
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shivasaxena ◴[10 Jul 25 21:12 UTC] No.44525677[source]▶
Yeah, I'm going to remove triggers in next deploy of a POS system since they are adding 10-50ms to each insert.

Becomes a problem if you are inserting 40 items to order_items table.

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GuinansEyebrows ◴[10 Jul 25 21:20 UTC] No.44525741[source]▶
that, and keeping your business logic in the database makes everything more opaque!
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lelanthran ◴[10 Jul 25 23:12 UTC] No.44526749[source]▶
> that, and keeping your business logic in the database makes everything more opaque!

Opaque to who? If there's a piece of business logic that says "After this table's record is updated, you MUST update this other table", what advantages are there to putting that logic in the application?

When (not if) some other application updates that record you are going to have a broken database.

Some things are business constraints, and as such they should be moved into the database if at all possible. The application should never enforce constraints such as "either this column or that column is NULL, but at least one must be NULL and both must never be NULL at the same time".

Your database enforces constraints; what advantages are there to code the enforcement into every application that touches the database over simply coding the constraints into the database?

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1. thisoneisreal ◴[10 Jul 25 23:38 UTC] No.44526911[source]▶
I think the dream is that business requirements are contained to one artifact and everything else responds to that driver. In an ideal world, it would be great to have databases care only about persistence and be able to swap them out based on persistence needs only. But you're right, in the real world the database is much better at enforcing constraints than applications.