RE: Queueing Theory in Oracle

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Tue, 11 Mar 2014 14:30:05 +0000
Message-ID: <CE70217733273F49A8A162EE074F64D901DE2468_at_exmbx05.thus.corp>

It's an interesting question - and I don't think you can find a current metric that would help unless you started doing something a little clever with ASH.

In an OLTP system something like 'buffer gets per user call" would probably be a reasonable fit - but there's no capture at that granularity. Similarly disc I/O requests per call might be appropriate. Then there are things like disk I/O requests per disc per second. But every possibility I think of requires too fine a level of granularity unless you can find a way to construct a valid model from the samples in v$active_session_history.

Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
_at_jloracle

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From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] on behalf of Ls Cheng [exriscer_at_gmail.com] Sent: 11 March 2014 14:20
To: Paul Houghton
Cc: Oracle Mailinglist
Subject: Re: Queueing Theory in Oracle

Hi

I have had a quick read, I think the link you posted talks about queue time but not about queueing theory such as a M/M/n model. The problem is I am not able to find a database metric that is exponential distributed which allows us to use the M/M/n queueing theory.

Thanks

On Tue, Mar 11, 2014 at 3:16 PM, Paul Houghton <Paul.Houghton_at_admin.cam.ac.uk<mailto:Paul.Houghton_at_admin.cam.ac.uk>> wrote: Craig Shallahamer talks about queuing theory in the following blog post.

http://shallahamer-orapub.blogspot.co.uk/2011/08/why-tuning-oracle-works-and-modeling-it.html

I hope this is helpful

PaulH

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Received on Tue Mar 11 2014 - 15:30:05 CET