RE: DBWR, Direct I/O and the Devil

You can remove the dbwriter parameter and let Oracle set it automatically based on the number of CPUs on your system.

-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Don Seiler Sent: Wednesday, November 28, 2007 2:39 PM To: Taylor, Chris David
Cc: Oracle-L Freelists
Subject: Re: DBWR, Direct I/O and the Devil

On Nov 28, 2007 1:32 PM, Taylor, Chris David <Chris.Taylor_at_ingrambarge.com> wrote:
> Do you believe you have an I/O issue or are you just trying to
"squeeze"
> more out of your I/O subsystem?

Right now I just want to know that I don't have some horribly obvious (to everyone else) misconfiguration. Obviously having a stable setup is paramount, I'll worry about tuning again after that. With my recent rash of performance issues, I'm going through any and all configuration changes that I made in the past 3 months and questioning everything.

> Having played with db_writer_processes, I haven't really seen much
> improvement or negative impact from increasing/decreasing them. But
> that is probably more due to the load (or lack thereof to notice any
> difference).

As I said, I'm all in favor of dropping down to 1, maybe back up to 2 if need be. I just wanted to know if there's any concerns to be aware of with the number of DBWR processes in direct vs. asynch I/O.

--
Don Seiler
http://seilerwerks.wordpress.com
ultimate: http://www.mufc.us
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