Re: Measuring db time / waiit events over a given period

From: Randolf Geist <mahrah_at_web.de>
Date: Tue, 1 Nov 2011 02:28:20 -0700 (PDT)
Message-ID: <d3763a1d-dbb8-4a75-8f97-3e339dabaf69_at_j20g2000vby.googlegroups.com>



On Oct 31, 10:08 am, dba cjb <chris.br..._at_providentinsurance.co.uk> wrote:
> db 10.2.0.4 enterprise on windows 2003
>
> I would like to measure db time over a sample period so that I can get
> a feel both for activity & bottlenecks on a given database.

What you are looking for has been invented previously. If you happen to have a Diagnostic Pack License on top of your Enterprise Edition you can simply use Active Session History (ASH) to understand the DB Time and Wait Events sampled over time.

If you don't have a Diagnostic License there are several free ASH implementations that you can use even with Standard Edition or pre-10g releases.

Start here for the free implementations: http://ashmasters.com/

It's also available via Sourceforge.net: http://sourceforge.net/projects/orasash/

There is also the free ASH Viewer that supports both, Oracle's ASH as well as its own implementation: http://sourceforge.net/projects/ashv/

As well as the old ASHMON also available via above ASHMASTERS link.

The free implementation was originally done by Kyle Hailey (http:// dboptimizer.com), the latest version of OraSASH has been maintained by Marcin Przepiorowski (http://oracleprof.blogspot.com/)

If you want to understand how to interpret / analyze ASH data, see this presentation by Graham Wood (one of the fathers of ASH / ADDM):

http://www.oracle.com/technetwork/database/focus-areas/manageability/ppt-active-session-history-129612.pdf

You can even watch him presenting about ASH:

http://www.oaktable.net/media/mow2010-graham-wood-ashes-time-part1 http://www.oaktable.net/media/mow2010-graham-wood-ashes-time-part-2

Hope this helps,
Randolf Received on Tue Nov 01 2011 - 04:28:20 CDT

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