Re: allow changing autovacuum_max_workers without restarting

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 appropriate limit that won't quickly become outdated.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