Re: DBWR - How Many is Too Many?
From: Niall Litchfield <niall.litchfield_at_gmail.com>
Date: Thu, 28 Feb 2008 07:23:45 +0000
Message-ID: <7765c8970802272323h2a588181l6c5b2561e27447ef@mail.gmail.com>
Date: Thu, 28 Feb 2008 07:23:45 +0000
Message-ID: <7765c8970802272323h2a588181l6c5b2561e27447ef@mail.gmail.com>
Great points both,
I'd also look at the i/o figures in your statspack report, I can't remember if 9i gives the histograms but it certainly will give you the average IO times experienced by your database. Often times SAN people can't/don't measure time but utilisation.
Niall
On Wed, Feb 27, 2008 at 9:49 PM, Greg Rahn <greg_at_structureddata.org> wrote:
>
> If you are experiencing high wait IO (>40% is high), then what benefit is
> there to potentially do more IO, by adding dbwrs?
>
> The other observation I would make is that if you changed the SAN, and not
> the database, and it worked ok before, then in all likelihood it is not a
> database problem. No?
>
-- Niall Litchfield Oracle DBA http://www.orawin.info -- http://www.freelists.org/webpage/oracle-lReceived on Thu Feb 28 2008 - 01:23:45 CST