-----Original Message----- From: Peter Geoghegan <p...@bowt.ie> Sent: Thursday, July 22, 2021 12:14 To: Tom Lane <t...@sss.pgh.pa.us> Cc: Jeff Davis <pg...@j-davis.com>; l...@laurent-hasson.com; David Rowley <dgrowle...@gmail.com>; Justin Pryzby <pry...@telsasoft.com>; pgsql-performa...@postgresql.org Subject: Re: Big performance slowdown from 11.2 to 13.3
On Thu, Jul 22, 2021 at 8:45 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > That is ... weird. Maybe you have found a bug in the spill-to-disk > logic; it's quite new after all. Can you extract a self-contained > test case that behaves this way? I wonder if this has something to do with the way that the input data is clustered. I recall noticing that that could significantly alter the behavior of HashAggs as of Postgres 13. -- Peter Geoghegan I could execute that test and re-cluster against the index. But I believe that's already done? Let me check. Thank you, Laurent.
