RE: System Statistics and Calibrate IO

Date: Sat, 3 Dec 2011 00:21:09 +0000
Message-ID: <>

My understanding was that db_calibrate was very narrowly focused, and only collects metrics on disk i/o- and I did not think those metrics were kept to influence the DB behavior. In other words, sort of like the same function as Orion- a benchmark and nothing more. Even if it did save those metrics (and show me the docs where it says it does) gather_system_stats captures a lot more info, including CPU performance.

To err on the safe side- run them both.

-----Original Message-----

From: [] On Behalf Of Kellyn Pot'vin Sent: Friday, December 02, 2011 7:15 PM
Subject: System Statistics and Calibrate IO

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? Thanks!
Kellyn Pot'Vin
Sr. Database Administrator and Developer

-- Received on Fri Dec 02 2011 - 18:21:09 CST

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