Re: Changing the autovacuum launcher scheduling; oldest table first algorithm

On Tue, Mar 6, 2018 at 11:27 PM, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> Hello
>
> I haven't read your respective patches yet, but both these threads
> brought to memory a patch I proposed a few years ago that I never
> completed:
>
> https://www.postgresql.org/message-id/flat/20130124215715.GE4528%40alvh.no-ip.org

Thank you for sharing the thread.

>
> In that thread I posted a patch to implement a prioritisation scheme for
> autovacuum, based on an equation which was still under discussion when
> I abandoned it. Chris Browne proposed a crazy equation to mix in both
> XID age and fraction of dead tuples; probably that idea is worth
> studying further. I tried to implement that in my patch but I probably
> didn't do it correctly (because, as I recall, it failed to work as
> expected). Nowadays I think we would also consider the multixact freeze
> age, too.
>
> Maybe that's worth giving a quick look in case some of the ideas there
> are useful for the patches now being proposed.

Yeah, that's definitely useful for the patches. I'll look at this and
will discuss that here.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center