Re: Should we remove vacuum_defer_cleanup_age?

Hi,

On 2023-03-22 11:44:20 -0500, Justin Pryzby wrote:
> On Sat, Mar 18, 2023 at 10:33:57AM +0100, Alvaro Herrera wrote:
> > On 2023-Mar-17, Andres Freund wrote:
> > 
> > > I started writing a test for vacuum_defer_cleanup_age while working on the fix
> > > referenced above, but now I am wondering if said energy would be better spent
> > > removing vacuum_defer_cleanup_age alltogether.
> > 
> > +1  I agree it's not useful anymore.
> > 
> > > I don't think I have the cycles to push this through in the next weeks, but if
> > > we agree removing vacuum_defer_cleanup_age is a good idea, it seems like a
> > > good idea to mark it as deprecated in 16?
> > 
> > Hmm, for the time being, can we just "disable" it by disallowing to set
> > the GUC to a value different from 0?  Then we can remove the code later
> > in the cycle at leisure.
> 
> It can be useful to do a "rolling transition", and it's something I do
> often.
> 
> But I can't see why that would be useful here?  It seems like something
> that could be done after the feature freeze.  It's removing a feature,
> not adding one.

It wasn't actually that much work to write a patch to remove
vacuum_defer_cleanup_age, see the attached.

I don't know whether others think we should apply it this release, given the
"late submission", but I tend to think it's not worth caring the complication
of vacuum_defer_cleanup_age forward.

Greetings,

Andres Freund