Re: System Statistics and Calibrate IO

From: Greg Rahn <>
Date: Fri, 2 Dec 2011 16:40:26 -0800
Message-ID: <>

I don't see a technical requirement to run either. I have yet to use system stats on any warehouse workload, and calibrate is only necessary for auto DOP, and then I would just set the values manually - the same way the Exadata best practice guide recommends. On Fri, Dec 2, 2011 at 4:15 PM, Kellyn Pot'vin <>wrote:

> I'm looking for some *extra* info before I pull my hair out on this one,
> folks!
> I'm managing and performing an 11g upgrade project and today, there was
> concern raised about me adding the dbms_resource_manager.calibrate_io run
> instead of gather_system_stats in a database build process. Over the last
> couple years reading here and there, I had come to believe that
> calibrate_IO was something of a replacement for gather_system_stats, but
> after research today, I'm not so sure about that!
> I have the basics down and am quite comfortable with the technical specs
> of the new calibrate IO feature, but still feel there may very well be some
> great value to gathering system stats, (This is for a mart build, is run
> once with a sufficient work load produced on the system at the initial
> build time, never again for the life of the datamart...)
> Can someone tell me why I would want to run one over the other, run both
> or where I'm missing some data here?

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Received on Fri Dec 02 2011 - 18:40:26 CST

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