From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Anjan Dave <adave@vantage.com>
Cc: Vivek Khera <vivek@khera.org>
Cc: Postgresql Performance <pgsql-performance@postgresql.org>
Subject: Re: High context switches occurring
Date: Tue, 6 Dec 2005 23:34:04 -0500 (EST)
Message-ID: <200512070434.jB74Y4o20004@candle.pha.pa.us> (raw)
In-Reply-To: <22673.1133912703@sss.pgh.pa.us>
Tom Lane wrote:
> "Anjan Dave" <adave@vantage.com> writes:
> > -bash-3.00$ time pgbench -c 1000 -t 30 pgbench
> > starting vacuum...end.
> > transaction type: TPC-B (sort of)
> > scaling factor: 1
> > number of clients: 1000
> > number of transactions per client: 30
> > number of transactions actually processed: 30000/30000
> > tps = 45.871234 (including connections establishing)
> > tps = 46.092629 (excluding connections establishing)
>
> I can hardly think of a worse way to run pgbench :-(. These numbers are
> about meaningless, for two reasons:
>
> 1. You don't want number of clients (-c) much higher than scaling factor
> (-s in the initialization step). The number of rows in the "branches"
> table will equal -s, and since every transaction updates one
Should we throw a warning when someone runs the test this way?
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
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To: pgsql-performance@postgresql.org
Cc: pgman@candle.pha.pa.us, tgl@sss.pgh.pa.us, adave@vantage.com, vivek@khera.org
Subject: Re: High context switches occurring
In-Reply-To: <200512070434.jB74Y4o20004@candle.pha.pa.us>
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