From: Tom Lane <tgl@sss.pgh.pa.us>
To: Javier Reyes <c.javier.reyes.e@gmail.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: Option shared_buffers in PostgreSQL
Date: Sun, 01 May 2011 12:17:10 -0400
Message-ID: <18735.1304266630@sss.pgh.pa.us> (raw)
In-Reply-To: <BANLkTikfpYSRHMpEQ6CqCk2Qz5_9OUBe1g@mail.gmail.com>
References: <BANLkTikfpYSRHMpEQ6CqCk2Qz5_9OUBe1g@mail.gmail.com>
Javier Reyes <c.javier.reyes.e@gmail.com> writes:
> I have a server with 4GB of RAM and PostgreSQL 9.0.3 on Centos 5. I'm using
> pgbench and pgbench-tools to measure performance, using two pgbench-tools
> queries: select and tpc-b.
> With default settings of postgresql.conf and select query, I get the
> following results:
> Scale: 1, 10, 100, 1000.
> Transactions per second: 10000, 8800, 7500, 100.
These numbers look like complete junk from here. I suspect you were
using a number-of-transactions parameter that's too small to give stable
answers. If you don't have the value set high enough so that each
pgbench run lasts at least a couple of minutes, I wouldn't put any
credence in the results. See also the other "good practices" mentioned
at the bottom of the pgbench documentation page.
regards, tom lane
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To: pgsql-admin@postgresql.org
Cc: tgl@sss.pgh.pa.us, c.javier.reyes.e@gmail.com
Subject: Re: Option shared_buffers in PostgreSQL
In-Reply-To: <18735.1304266630@sss.pgh.pa.us>
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