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

Inoue, Hiroshi <inoue@tpf.co.jp>

From: "Hiroshi Inoue" <Inoue@tpf.co.jp>
To: "Tom Lane" <tgl@sss.pgh.pa.us>, "Hannu Krosing" <hannu@tm.ee>
Cc: "Tatsuo Ishii" <t-ishii@sra.co.jp>, <pgsql-hackers@postgresql.org>, <pgsql-admin@postgresql.org>
Date: 2001-02-23T21:38:27Z
Lists: pgsql-hackers
> -----Original Message-----
> From: Tom Lane
> 
> Hannu Krosing <hannu@tm.ee> writes:
> > Is this unmodified pgbench or has it Hiroshi tweaked behaviour of 
> > connecting each client to its own database, so that locking and such 
> > does not shade the possible benefits (was it about 15% ?) of delay>1
> 
> I didn't much like that approach to altering the test, since it also
> means that all the clients are working with separate tables and hence
> not able to share read I/O; that doesn't seem like it's the same
> benchmark at all.

I agree with you at this point. Generally speaking the benchmark
has little meaning if it has no conflicts in the test case. I only
borrowed pgbench's source code to implement my test cases.
Note that there's only one database in my last test case. My
modified "pgbench" isn't a pgbench any more and I didn't intend
to change pgbench's spec like that. Probably it was my mistake
that I had posted my test cases using the form of patch.  My
intension was to clarify the difference of my test cases.
However heavy conflicts with scaling factor 1 doesn't seem
preferable at least as the default of pgbench.

Regards,
Hiroshi Inoue