From: Craig Ringer <craig@postnewspapers.com.au>
To: Fernando Mertins <fernando.mertins@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Same stament sometime fast, something slow
Date: Wed, 05 Jan 2011 12:24:19 +1100
Message-ID: <4D23C843.8040804@postnewspapers.com.au> (raw)
In-Reply-To: <AANLkTinnMdESL8mycy6P6NWDrYPABLns0_v3Ct9Z-6Zj@mail.gmail.com>
References: <AANLkTinnMdESL8mycy6P6NWDrYPABLns0_v3Ct9Z-6Zj@mail.gmail.com>
On 01/05/2011 05:03 AM, Fernando Mertins wrote:
> Hi there, this is my first post.
>
> I have a PostgreSQL 8.3.6, compiled by Visual C++ build 1400 running on
> Windows with virtual machine
^^^^^^^^^^^^^^^^^^^^
What kind of VM host? where? what else is on the same host?
Your most likely culprit is I/O contention from other guests on the same
host, possibly combined with I/O queuing policies on the host that
favour throughput over request latency.
Checkpoints might also be a factor.
--
Craig Ringer
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To: pgsql-performance@postgresql.org
Cc: craig@postnewspapers.com.au, fernando.mertins@gmail.com
Subject: Re: Same stament sometime fast, something slow
In-Reply-To: <4D23C843.8040804@postnewspapers.com.au>
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