Re: Should we increase the default vacuum_cost_limit?

On Tue, 26 Feb 2019 at 02:06, Joe Conway <mail(at)joeconway(dot)com> wrote:
>
> On 2/25/19 1:17 AM, Peter Geoghegan wrote:
> > On Sun, Feb 24, 2019 at 9:42 PM David Rowley
> > <david(dot)rowley(at)2ndquadrant(dot)com> wrote:
> >> The current default vacuum_cost_limit of 200 seems to be 15 years old
> >> and was added in f425b605f4e.
> >>
> >> Any supporters for raising the default?
> >
> > I also think that the current default limit is far too conservative.
>
> I agree entirely. In my experience you are usually much better off if
> vacuum finishes quickly. Personally I think our default scale factors
> are horrible too, especially when there are tables with large numbers of
> rows.

Agreed that the scale factors are not perfect, but I don't think
changing them is as quite a no-brainer as the vacuum_cost_limit, so
the attached patch just does the vacuum_cost_limit.

I decided to do the times by 10 option that I had mentioned.... Ensue
debate about that...

I'll add this to the March commitfest and set the target version as PG12.

--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services