Re: Average physical read times
Date: Wed, 24 Sep 2008 18:45:39 +0100
Dan 11 ms isnt a terrible average at all. Do you have a version where you get the distribution of times though? you could be hiding fast and slow disks in the average. The frequency distribution will show this.
On 24/09/2008, Daniel Fink <daniel.fink_at_optimaldba.com> wrote:
> In a recent optimization effort, I found what I think are high physical
> read times. For example, a single block read was averaging 11
> milliseconds with a max of over 1 second (tkprof output). For this
> session, single block reads consumed over 80% of the response time, so
> this is of concern.
> We are running Oracle 10gr1 on AIX with an IBM storage array (shared
> amongst many servers). I suspect there is some optimization that can be
> done at the storage array level. If 11 milliseconds is well above
> average, this will help in engaging that team in the process.
> For those of you running statspack. AWR or other monitoring tools, what
> are the average single block read times you are encountering on a good
> system? If you are running on an IBM storage array, have you found any
> specific issues/fixes?
> Daniel Fink
> Daniel Fink
> OptimalDBA.com - Oracle Performance, Diagnosis, Data Recovery and Training
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-- Niall Litchfield Oracle DBA http://www.orawin.info -- http://www.freelists.org/webpage/oracle-lReceived on Wed Sep 24 2008 - 12:45:39 CDT