From: Craig James <craig_james@emolecules.com>
To: pgsql-performance@postgresql.org
Subject: Re: write barrier question
Date: Wed, 18 Aug 2010 12:56:57 -0700
Message-ID: <4C6C3B09.6040504@emolecules.com> (raw)
In-Reply-To: <AANLkTim0X2oZ61dzvwG_+TWf94DLEr_0Q_hecq57EZ6+@mail.gmail.com>
References: <AANLkTim0X2oZ61dzvwG_+TWf94DLEr_0Q_hecq57EZ6+@mail.gmail.com>
On 8/18/10 12:24 PM, Samuel Gendler wrote:
> With barriers off, I saw a transaction rate of about 1200. With
> barriers on, it was closer to 1050. The test had a concurrency of 40
> in both cases.
I discovered there is roughly 10-20% "noise" in pgbench results after running the exact same test over a 24-hour period on a machine with no other activity. Be sure you run your tests enough times to get good statistics unless you're looking at much larger differences.
Craig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: craig_james@emolecules.com
Subject: Re: write barrier question
In-Reply-To: <4C6C3B09.6040504@emolecules.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox