Message-ID: <7d31e25d6cdd46ab94559179268e61413849d741.camel@cybertec.at>
Subject: Re: Using PGTune - is it a good source for system configuration?
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: =?ISO-8859-1?Q?P=F3l?= Ua =?ISO-8859-1?Q?Lao=EDnech=E1in?=
	 <linehanp@tcd.ie>, pgsql-novice@lists.postgresql.org
Date: Wed, 01 Sep 2021 20:01:48 +0200
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On Wed, 2021-09-01 at 17:19 +0100, Pól Ua Laoínecháin wrote:
> I used PGTune to obtain system configuration recommendations. I'm
> wondering if these can be taken as "gospel" or are there any caveats
> or "gotchas" to be aware of?

It is a serving suggestion and gives you food for thought.

It does not substitute thinking for yourself and reading the documentation
for those parameters.

> # DB Version: 13
> # OS Type: linux
> # DB Type: mixed
> # Total Memory (RAM): 32 GB
> # CPUs num: 2
> # Data Storage: ssd
> 
> max_parallel_workers_per_gather = 1
> max_parallel_workers = 2
> max_parallel_maintenance_workers = 1

For example, I think these are not sane values for a mixed workload
with 2 CPU cores.

With that configuration, a single query could keep both cores busy.
I'd set all these to 0.

Yours,
Laurenz Albe
-- 
Cybertec | https://www.cybertec-postgresql.com