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

> -----Original Message-----
> From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
> 
> Hiroshi Inoue <Inoue@tpf.co.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