From: David Boreham <david_list@boreham.org>
To: pgsql-performance@postgresql.org
Subject: Re: WAL in RAM
Date: Fri, 28 Oct 2011 13:55:49 -0600
Message-ID: <4EAB08C5.7050206@boreham.org> (raw)
In-Reply-To: <70afb7c488aca8f564f4b569f857747b.squirrel@sq.gransy.com>
References: <4EAACA17.7010503@engene.se>
<CAHyXU0xNW6ihoqWMn7tyqP5iEsYB-63v=+FiGVXDkQtWiw=CtQ@mail.gmail.com>
<70afb7c488aca8f564f4b569f857747b.squirrel@sq.gransy.com>
On 10/28/2011 12:26 PM, Tomas Vondra wrote:
> For example the Intel 710 SSD has a sequential write speed of 210MB/s,
> while a simple SATA 7.2k drive can write about 50-100 MB/s for less than
> 1/10 of the 710 price.
Bulk data transfer rates mean almost nothing in the context of a database
(unless you're for example backing it up by copying the files to another
machine...)
The key factor typically is small block writes/s (for WAL) and random
small block
reads/s (for data). 710 or similar performance SSDs will deliver on the
order
of 20-50x the performance of a traditional hard drive in these areas.
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To: pgsql-performance@postgresql.org
Cc: david_list@boreham.org
Subject: Re: WAL in RAM
In-Reply-To: <4EAB08C5.7050206@boreham.org>
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