On Sun, Jan 18, 2015 at 07:02:54PM -0500, Tom Lane wrote:
> Noah Misch <noah@leadboat.com> writes:
> > On Sun, Jan 18, 2015 at 04:09:29PM -0500, Tom Lane wrote:
> >> After looking at the code, the minimum-change alternative would be more or
> >> less as attached: first, get rid of the long-obsolete proposition that
> >> autovacuum workers need fresher-than-usual stats; second, allow
> >> pgstat_vacuum_stat to accept stats that are moderately stale (the number
> >> given below allows them to be up to 50 seconds old); and third, suppress
> >> wait-timeout warnings when the call is from pgstat_vacuum_stat. The third
> >> point is what we need to avoid unnecessary buildfarm failures. The second
> >> point addresses the idea that we don't need to stress the stats collector
> >> too much for this.
>
> > Only #3 belongs in a minimum-change patch. #1 and #2 solve and/or create
> > different problems and operate independently of #3. A patch covering #3 alone
> > sounds attractive.
>
> [ raised eyebrow... ] In your previous message, you were advocating *for*
> a change that was more invasive than this one. Why the change of heart?
I phrased that proposal based on a wrong belief that the collector writes the
stats file regularly in any case. Vacuuming a 49s-old stats file without even
trying to get a fresh one might or might not improve PostgreSQL, but it's
dissimilar to what I had in mind. I did not advocate for #1 at any point.
> In particular, I thought we'd already agreed to point #1.
Nope. You and Alvaro ACKed it, then Heikki NACKed it.