Re: another autovacuum scheduling thread

On Sat, Nov 22, 2025 at 06:28:13AM -0500, Robert Haas wrote:
> What would be an issue is if we
> regressed some kind of common pattern. I admit that's a bit
> speculative and I'm probably being a little paranoid here: doing smart
> things is typically better than doing dumb things, and what we're
> doing right now is dumb.
>
> On the other hand, once we ship something, we can't pull it back. If
> it causes a problem, someone will call me at 2am and need their system
> fixed right now. If my answer is "well, there are no configuration
> knobs we can change and no way to get back to the old behavior and I'm
> sorry you're having that problem but the only answer is for you to run
> all your VACUUMs manually until two years from now when maybe the
> algorithm will have been improved," it's not going to be a very good
> night. After 15 years at EDB, I've learned that the problem isn't
> being wrong per se; it's having no way to get out from under being
> wrong.

Yeah. I'm tempted to code up the "weighting factor" GUCs for the next
revision. As you've noted, those would be useful for tuning and for
reverting back to pre-v19 behavior. Sure, we might end up with a handful
of retail GUCs that most users don't need, but that's not so terrible.

--
nathan