From: Nathan Bossart <nathandbossart@gmail.com>
To: Imseih (AWS), Sami <simseih@amazon.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@postgresql.org <pgsql-hackers@postgresql.org>
Subject: Re: allow changing autovacuum_max_workers without restarting
Date: Thu, 2 May 2024 20:04:15 -0500
Message-ID: <20240503010415.GA1008894@nathanxps13> (raw)
In-Reply-To: <96B4FC7B-A919-4F93-80A3-BA3EA4F8479A@amazon.com>
References: <20240410212344.GA1824549@nathanxps13>
<Zh0srZSCSfcK_oY9@pryzbyj2023>
<20240415162833.GA2857238@nathanxps13>
<20240415163749.GA2858464@nathanxps13>
<96B4FC7B-A919-4F93-80A3-BA3EA4F8479A@amazon.com>
On Mon, Apr 15, 2024 at 05:41:04PM +0000, Imseih (AWS), Sami wrote:
>> Another option could be to just remove the restart-only GUC and hard-code
>> the upper limit of autovacuum_max_workers to 64 or 128 or something. While
>> that would simplify matters, I suspect it would be hard to choose an
>> appropriate limit that won't quickly become outdated.
>
> Hardcoded values are usually hard to deal with because they are hidden either
> In code or in docs.
That's true, but using a hard-coded limit means we no longer need to add a
new GUC. Always allocating, say, 256 slots might require a few additional
kilobytes of shared memory, most of which will go unused, but that seems
unlikely to be a problem for the systems that will run Postgres v18.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: nathandbossart@gmail.com, simseih@amazon.com, pryzby@telsasoft.com
Subject: Re: allow changing autovacuum_max_workers without restarting
In-Reply-To: <20240503010415.GA1008894@nathanxps13>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox