Re: Postgresql 8.0 beta 1 - strange cpu usage statistics and slow vacuuming

Shelby Cain <alyandon(at)yahoo(dot)com> writes:
> I'm putting 8.0 through its paces and here are a few
> things I've noticed on the native win32 port running
> on my workstation (2.0g p4 w/256 megs of ram).

> Here is the output of "vacuum verbose item":

> DETAIL: CPU -1.-1612s/-1.99u sec elapsed 1434.79 sec.
> ...
> CPU 1081264882.-821s/0.02u sec elapsed 1682.87 sec.

Hmm ... something broken about getrusage() on Windows?
CC'd to pgsql-hackers-win32 for comment.

> My other concern is the length of time that vacuum
> runs when cost based vacuuming is disabled.

Are you sure you had cost-based vac disabled? I tried to reproduce
your experiment here. I saw some degradation in vacuuming speed
but not nearly as large as you're reporting (85 vs 73 seconds),
and as far as I could tell it was still maxing out my disk.
But the behavior you're describing is exactly what I'd expect if
cost-based vac was on.

regards, tom lane