RE: perplexing performance on AIX

From: Baumgartel, Paul <paul.baumgartel_at_credit-suisse.com>
Date: Tue, 6 May 2008 16:11:57 -0400
Message-ID: <21469B88E0EA11498818517F2103353101C6631E@EPRI17P32001A.csfb.cs-group.com>


On Tue, May 6, 2008 at 2:21 PM, Allen, Brandon
<Brandon.Allen_at_oneneck.com <mailto:Brandon.Allen_at_oneneck.com> > wrote:

        If you disabled parallellism, you couldn't get PX wait events. You might want to try with DOP of 1. I'd also verify CIO is being used if you aren't sure.    

Reminds me of the old Henny Youngman joke: "I went to the doctor. I said 'Doc, it hurts when I do this.' He said 'Don't do that.'"

Paul Baumgartel
CREDIT SUISSE
Information Technology
Prime Services Databases Americas
One Madison Avenue
New York, NY 10010
USA
Phone 212.538.1143
paul.baumgartel_at_credit-suisse.com
www.credit-suisse.com  


From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of John Smith Sent: Tuesday, May 06, 2008 3:29 PM
To: Allen, Brandon; oracle-l_at_freelists.org Subject: Re: perplexing performance on AIX

We really want to be able to use parallel.


	From: John Smith [mailto:john40855_at_gmail.com] 
	Sent: Tuesday, May 06, 2008 11:57 AM
	To: Allen, Brandon
	Subject: Re: perplexing performance on AIX
	
	
	Yes, we tried decreasing the DOP.   Didnt really affect the wait
event. I am pretty sure the drives are already mounted w/ CIO. At least they are supposed to be.                  

        On Tue, May 6, 2008 at 1:20 PM, Allen, Brandon
<Brandon.Allen_at_oneneck.com> wrote:
        

                Have you tried decreasing the degree of parallelism (or maybe even disabling it) to see if that helps? Sometimes too much parallelism is a bad thing.                  

                You might also want to consider using concurrent IO if you're not already.                  

		Regards,
		Brandon
		 
		 
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Received on Tue May 06 2008 - 15:11:57 CDT

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