Plan to support predicate push-down into subqueries with aggregates? - Mailing list pgsql-general

From Adam Brusselback
Subject Plan to support predicate push-down into subqueries with aggregates?
Date
Msg-id CAMjNa7cYSi8aXe=thZZvuXpwcLUnQHORPNb0YETgUn5z5ZVi1Q@mail.gmail.com
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Responses Re: Plan to support predicate push-down into subqueries with aggregates?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Hi all.
I was wondering if there were any plans to support predicate push-down optimization for subqueries (and views) with aggregates?

I was recently bit by this, as I had incorrectly assumed that this was an optimization that was in place, and designed quite a bit around that assumption, only to get hit with terrible performance when more data got loaded into the system.

Currently I had to solve the issue by having aggregate tables which store the data, which is maintained by triggers on IUD.  This gets messy quick, as I have some aggregates which are dependent on 5-6 other tables.  I'd love to be able to just store the logic for calculating aggregates in a view, and use that at query time instead of having to deal with it like this.

I have written a test case script that explains the type of queries I am talking about, and the issues.  It's heavily simplified compared to a real system, but it'll do.  Please see attached.

Thanks,
-Adam
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