OK. Will do another round of testing.
-----Original Message-----
From: David Rowley <dgrowleyml@gmail.com>
Sent: Thursday, July 22, 2021 00:44
To: ldh@laurent-hasson.com
Cc: Tom Lane <tgl@sss.pgh.pa.us>; Peter Geoghegan <pg@bowt.ie>; Justin Pryzby <pryzby@telsasoft.com>;
pgsql-performance@postgresql.org
Subject: Re: Big performance slowdown from 11.2 to 13.3
On Thu, 22 Jul 2021 at 16:37, ldh@laurent-hasson.com <ldh@laurent-hasson.com> wrote:
> Seems like no cigar ☹ See plan pasted below. I changed the conf as follows:
> - hash_mem_multiplier = '2'
> - work_mem = '1GB'
> Batches: 5 Memory Usage: 2400305kB Disk Usage: 126560kB
You might want to keep going higher with hash_mem_multiplier until you see no "Disk Usage" there. As mentioned, v11
didn'tspill to disk and just used all the memory it pleased. That was a bit dangerous as it could result in OOM, so it
wasfixed.
David