Just a quick thought: after each run/sample of pgbench, I drop the
database and recreate it. When I don't my results become more skewed.
Thomas F.O'Connell wrote:
> Interesting. I should've included standard deviation in my pgbench
> iteration patch. Maybe I'll go back and do that.
> I was seeing oscillation across the majority of iterations in the 25
> clients/1000 transaction runs on both database versions.
> I've got my box specs and configuration files posted. If you see
> anything obvious about the tuning parameters that should be tweaked,
> please let me know.
> Thanks for the feedback!
> Thomas F. O'Connell
> Co-Founder, Information Architect
> Sitening, LLC
> Strategic Open Source: Open Your iâ„¢
> 110 30th Avenue North, Suite 6
> Nashville, TN 37203-6320
> On Apr 25, 2005, at 1:58 AM, Steve Poe wrote:
>> >There was some interesting oscillation behavior in both version of
>> postgres that occurred with 25 >clients and 1000 transactions at a
>> scaling factor of 100. This was repeatable with the distribution
>> >version of pgbench run iteratively from the command line. I'm not
>> sure how to explain this.
>> When you see these oscillations, do they occur after so many
>> generated results? Some oscillation is normal, in my opinion, from
>> 10-15% of the performance is noise-related.
>> The key is to tune the server that you either 1) minimize the
>> oscillation and/or 2)increase your overall performance above the
>> 10-15% baseline, and 3) find out what the mean and standard deviation
>> between all your results.
>> If your results are within that range, this maybe "normal". I
>> follow-up with you later on what I do.
>> Steve Poe
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