Re: High load, - Mailing list pgsql-performance

From Andres Freund
Subject Re: High load,
Date
Msg-id 201101271919.35382.andres@anarazel.de
Whole thread Raw
In response to Re: High load,  (Scott Marlowe <scott.marlowe@gmail.com>)
List pgsql-performance
On Thursday, January 27, 2011 07:13:17 PM Scott Marlowe wrote:
> On Thu, Jan 27, 2011 at 10:54 AM, Stephen Frost <sfrost@snowman.net> wrote:
> > * Michael Kohl (michael.kohl@tupalo.com) wrote:
> >> HDD: 2x 120 GB OCZ Vertex 2 SSD; RAID 1
> >
> > I'm amazed no one else has mentioned this yet, but you should look into
> > splitting your data and your WALs.  Obviously, having another set of
> > SSDs to put your WALs on would be ideal.
>
> Actually spinning media would be a better choice.  A pair of fast
> 15krpm drives in a mirror will almost always outrun an SSD for
> sequential write speed.  Even meh-grade 7200RPM SATA drives will win.
Unless he is bulk loading or running with synchronous_commit=off sequential
speed wont be the limit for WAL. The number of syncs will be the limit.

Andres

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