Re: Rapidly decaying performance repopulating a large table

On Tue, Apr 22, 2008 at 3:15 PM, David Wilson <david(dot)t(dot)wilson(at)gmail(dot)com> wrote:
> On Tue, Apr 22, 2008 at 5:04 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
> > Normally, after the first 50,000 or so the plan won't likely change
> > due to a new analyze, so you could probably just analyze after 50k or
> > so and get the same performance. If the problem is a bad plan for the
> > inserts / copies.
> >
> > also, non-indexed foreign keyed fields can cause this problem.
> >
>
> Analyzing after the first 50k or so is easy enough, then; thanks for
> the suggestion.
>
> Foreign keys are definitely indexed (actually referencing a set of
> columns that the foreign table is UNIQUE on).
>
> Any other suggestions? COPY times alone are pretty much quadrupling my
> table-rebuild runtime, and I can interrupt the current rebuild to try
> things pretty much at a whim (nothing else uses the DB while a rebuild
> is happening), so I'm pretty much game to try any reasonable
> suggestions anyone has.

Try upping your checkpoint segments. Some folks find fairly large
numbers like 50 to 100 to be helpful. Each segment = 16Megs, so be
sure not to run your system out of drive space while increasing it.