Re: inheritance: planning time vs children number vs column number

The Tuesday 01 March 2011 16:33:51, Tom Lane wrote :
> Marc Cousin <cousinmarc(at)gmail(dot)com> writes:
> > Le mardi 01 mars 2011 07:20:19, Tom Lane a écrit :
> >> It's worth pointing out that the only reason this effect is dominating
> >> the runtime is that you don't have any statistics for these toy test
> >> tables. If you did, the cycles spent using those entries would dwarf
> >> the lookup costs, I think. So it's hard to get excited about doing
> >> anything based on this test case --- it's likely the bottleneck would be
> >> somewhere else entirely if you'd bothered to load up some data.
> >
> > Yes, for the same test case, with a bit of data in every partition and
> > statistics up to date, planning time goes from 20 seconds to 125ms for
> > the 600 children/1000 columns case. Which is of course more than
> > acceptable.
>
> [ scratches head ... ] Actually, I was expecting the runtime to go up
> not down. Maybe there's something else strange going on here.
>
> regards, tom lane

Then, what can I do to help ?