RE: [HACKERS] Re: v7.1b4 bad performance

> -----Original Message-----
> From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
>
> Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp> writes:
> > I changed pgbench so that different connection connects
> > to the different database and got the following results.
>
> Hmm, you mean you set up a separate test database for each pgbench
> "client", but all under the same postmaster?
>

Yes. Different database is to make the conflict as less as possible.
The conflict among backends is a greatest enemy of CommitDelay.

> > The results of
> > pgbench -c 10 -t 100
>
> > [CommitDelay=0]
> > 1st)tps = 18.484611(including connections establishing)
> > tps = 19.827988(excluding connections establishing)
> > 2nd)tps = 18.754826(including connections establishing)
> > tps = 19.352268(excluditp connections establishing)
> > 3rd)tps = 18.771225(including connections establishing)
> > tps = 19.261843(excluding connections establishing)
> > [CommitDelay=1]
> > 1st)tps = 20.317649(including connections establishing)
> > tps = 20.975151(excluding connections establishing)
> > 2nd)tps = 24.208025(including connections establishing)
> > tps = 24.663665(excluding connections establishing)
> > 3rd)tps = 25.821156(including connections establishing)
> > tps = 26.842741(excluding connections establishing)
>
> What platform is this on --- in particular, how long a delay
> is CommitDelay=1 in reality? What -B did you use?
>

platform) i686-pc-linux-gnu, compiled by GCC egcs-2.91.60(turbolinux 4.2)
min delay) 10msec according to your test program.
-B) 64 (all other settings are default)

Regards,
Hiroshi Inoue