Re: Average physical read times
- From: "Andrew Kerber" <andrew.kerber@xxxxxxxxx>
- To: daniel.fink@xxxxxxxxxxxxxx
- Date: Wed, 24 Sep 2008 12:54:14 -0500
That is rarely above 10ms.
On Wed, Sep 24, 2008 at 12:50 PM, Andrew Kerber <andrew.kerber@xxxxxxxxx>wrote:
> I have seen as small as 2 ms, rarely about 10 ms. Did you check and see if
> the DBFMBRC might be set too high?
>
>
> On Wed, Sep 24, 2008 at 11:17 AM, Daniel Fink
> <daniel.fink@xxxxxxxxxxxxxx>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?
>>
>> Regards,
>> Daniel Fink
>>
>> --
>> Daniel Fink
>>
>> OptimalDBA.com - Oracle Performance, Diagnosis, Data Recovery and Training
>>
>> OptimalDBA http://www.optimaldba.com
>> Oracle Blog http://optimaldba.blogspot.com
>>
>> Lost Data? http://www.ora600.be/
>>
>> --
>> //www.freelists.org/webpage/oracle-l
>>
>>
>>
>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>
--
Andrew W. Kerber
'If at first you dont succeed, dont take up skydiving.'
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