Re: Performance difference between 2 machines

From: DA Morgan <damorgan_at_psoug.org>
Date: Wed, 22 Jun 2005 14:37:33 -0700
Message-ID: <1119490106.713038@yasure>

Matthias Hoys wrote:
> "DA Morgan" <damorgan_at_psoug.org> wrote in message
> news:1119473573.863885_at_yasure...
>

>>Matthias Hoys wrote:
>>
>>
>>>How could I benchmark the ideal configuration for our database ? Install 
>>>different databases with different block sizes ? That's a whole lot of 
>>>work, and we don't have the diskspace ...
>>
>>Wholly unnecessary waste of time. First you need to collect metrics from
>>Oracle and operating system that indicate what the issue(s) are.
>>-- 
>>Daniel A. Morgan
>>http://www.psoug.org
>>damorgan_at_x.washington.edu
>>(replace x with u to respond)

>
>
> Well, the issue is that after doing a lot of research and reading, I still
> don't know what the "optimal" block size would be for an Oracle 10g DWH on
> JFS2 on AIX 5.2 with async i/o. Some say 4K, some say a multiple of 4K ...
> We do not have any performance issues with our current 8.1.7 db with 16K
> block size (no high CPU usage, no swapping, no i/o waits ...). But maybe the
> performance can be even better with a lower block size ...

I think you missed my point.

The optimal block size for your operating system is 4K. End of discussion.

Build using 4K and then run StatsPack, sar, iostat, vmstat, etc. and see if there is a problem and where it is. Then, and only then, consider exploring actions that specifically address the specific issue found.

Right now you have no issues so this exercise is purely academic and strikes me as a great diversion from something else you don't want to do. ;-)

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Wed Jun 22 2005 - 16:37:33 CDT