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

Tom Lane wrote:
>
> Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp> writes:
> > In your test cases I always see "where bid = 1" at "update branches"
> > i.e.
> > update branches set bbalance = bbalance + ... where bid = 1
>
> > ISTM there's no multiple COMMIT in your senario-s due to
> > their lock conflicts.
>
> Hmm. It looks like using a 'scaling factor' larger than 1 is necessary
> to spread out the updates of "branches". AFAIR, the people who reported
> runs with scaling factors > 1 got pretty much the same results though.
>

People seem to believe your results are decisive
and would raise your results if the evidence is
required.
All clients of pgbench execute the same sequence
of queries. There could be various conflicts e.g.
oridinary lock, buffer lock, IO spinlock ...
I've been suspicious if pgbench is an (unique)
appropiriate test case for evaluaing commit_delay.

Regards,
Hiroshi Inoue