Re: Berserk Autovacuum (let's save next Mandrill)

On Sat, 2020-03-28 at 11:59 +1300, David Rowley wrote:
> On Fri, 27 Mar 2020 at 22:40, Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> wrote:
> > The new meaning of -2 should be documented, other than that it looks
> > good to me.
>
> But the users don't need to know anything about -2. It's not possible
> to explicitly set the value to -2. This is just the reset value of the
> reloption which means "use the GUC".

I see.

> > I'll accept the new semantics, but they don't make me happy. People are
> > used to -1 meaning "use the GUC value instead".
>
> The problem with having -1 on the reloption meaning use the GUC, in
> this case, is that it means the reset value of the reloption must be
> -1 and we need to allow them to set -2 explicitly, and if we do that,
> then -1 also becomes a valid value that users can set. Maybe that's
> not the end of the world, but I'd rather have the reset value be
> unsettable by users. To me, that's less confusing as there are fewer
> special values to remember the meaning of.
>
> The reason I want a method to explicitly disable the feature is the
> fact that it's easy to document and it should reduce the number of
> people who are confused about the best method to disable the feature.
> I know there's going to be a non-zero number of people who'll want to
> do that.

In the light of that, I have no objections.

Yours,
Laurenz Albe