RE: Oracle Tunning

From: K Gopalakrishnan <kaygopal_at_yahoo.com>
Date: Fri, 01 Feb 2002 03:20:49 -0800
Message-ID: <F001.00403041.20020201031528@fatcity.com>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Continuing my previous mail :

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style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Since you (as I always) have high respect for Steve Adams, Check what Steve says about that tip (in p607 Oracle Performance Tuning tips and techniques.. Richard Niemic) in his Ixora Q & A on
buffer cache at http://www.ixora.com.au/q+a/cache.htm

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>The one is dated 9th December 1999;

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style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Here is the excerpt:

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style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Topic :Free buffers 9 December 1999

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>Q: I have read in one of the performance books that "If free buffers are not available (none with STATE=0) within the first 30 minutes of business hours, you probably need to set db_block_buffers higher." I have checked, and we have no free buffers within a minute of startup, but my buffer cache hit ratio is already better than 99%.

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>

<span

style='font-size:10.0pt;mso-bidi-font-size:12.0pt;font-family:Arial'>A: The advice that free buffers should be available after a certain period is wrong prior to 8.1, and dubious for 8.1.

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<!---size:10.0pt;mso-bidi-font-size:

12.0pt;font-family:Arial'> AUTOTEXTLIST \s "E-mail Signature" Best Regards,

<span

style='font-size:12.0pt;color:navy'>K Gopalakrishnan

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-----Original
Message-----
From: root_at_fatcity.com
[mailto:root_at_fatcity.com]On Behalf Of SARKAR, Samir
Sent: Friday, February 01, 2002
2:25 AM
To: Multiple recipients of list
ORACLE-L
Subject: RE: Oracle Tunning

<span

style='font-size:12.0pt'>

Well
Mogens, Niemiec's book does have its plus points as well. What we basically want from Oracle

is
improved response times and faster performance........which is all about how many hits we r getting

and
improving the hit ratio is something any DBA will try to attain.

There
is a wonderful technique in his book about how to estimate the size of the db_block_buffers

by
mythically raising it by a certain amount and checking the hit ratio or decreasing it and checking

the
impact. This way, we can arrive at an optimum value for the db_block_buffers.

How to
interpret the UTLESTAT/UTLBSTAT statistics r very clearly and lucidly explained as r the various

join
methods, improper use of indexes including index suppression, using the x$bh table to monitor buffer use,

a very
clear explanation of the Explain Plan, new tips for Oracle 8/8i, how to use PL/SQL for better performance etc.

The
best part is the book has lots of very useful queries and screen reprints to help us understand the

scenario
better.

Am not
saying that it is the best tuning book in the market but the techniques of tuning r very clearly explained

in it.

Tuning
by wait events is still very arcane and not explained clearly exactly how to do it in many books though

I
haven't read the 101 book. I still find it difficult to properly interpret all the various wait events and latch contention

and how
to go about tuning them And until Steve Adams comes out with his advanced performance tuning book,

we will
all have to wait.

Samir

<span

style='font-size:10.0pt;font-family:Verdana;color:navy;font-weight:bold'>Samir Sarkar
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>Oracle DBA - Lennon Team
SchlumbergerSema
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>Email : samir.sarkar_at_nottingham.sema.slb.com
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>
samir.sarkar_at_sema.co.uk 
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>Phone : +44 (0) 115 - 957 6217
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>EPABX : +44 (0) 115 - 957 6418 Ext. 76217
<span

style='font-size:7.5pt;font-family:Verdana;color:navy;font-weight:bold; font-style:italic'>Fax : +44 (0) 115 - 957 6018

-----Original Message-----
From: Mogens Nørgaard
[mailto:mln_at_miracleas.dk]
Sent: 31 January 2002 18:39
To: Multiple recipients of list
ORACLE-L
Subject: Re: Oracle Tunning

Commit; :-)

In my opinion, you shouldn't spend your money on buying the Niemich book. It's full of errors (increase the buffer cache hit ratio, for instance) and the wrong approach (no time-based measurement method, just checklist after checklist).

Buy 101 by Gaja. Then buy Tom Kyte's One-On-One book for general fantastic advise on anything. Then go to oraperf.com (Anjo), hotsos.com (Millsap), ixora.com.au (Steve Adams) and Jonathan Lewis' website (can never remember the adresse). Or go to MiracleAS.dk and find all these links, including the book links.

Mogens
Miracle A/S
Denmark

Farnsworth, Dave wrote:

<pre style='mso-margin-top-alt:0in;margin-right:1.0in;margin-bottom:0in;
margin-left:1.5in;margin-bottom:.0001pt' wrap="">Binay,

I totally agree with this recommendation from Jared for a tuning book. Read the first three chapters, stop and re-read them. And if you play your cards right you can even get a question answered by an author on this list. Cool, eh.

Dave

-----Original Message-----
Sent: Tuesday, January 29, 2002 3:05 PM
To: Multiple recipients of list ORACLE-L

Start with 'Oracle Performance Tuning 101', available at an amazon.com near you.

Jared

On Tuesday 29 January 2002 09:10, BINAY.KUMAR_at_ponl.com wrote:<pre
style='mso-margin-top-alt:0in;margin-right:1.5in;margin-bottom:0in;margin-left: 2.0in;margin-bottom:.0001pt' wrap="">Hi Everyone

Can anyone suggest me some very good book on Oracle Tunning.<pre
style='mso-margin-top-alt:0in;margin-right:1.0in;margin-bottom:0in;margin-left: 1.5in;margin-bottom:.0001pt' wrap=""><span

style='font-size:10.0pt;color:black'>Please only<font
color=black><pre
style='mso-margin-top-alt:0in;margin-right:1.5in;margin-bottom:0in;margin-left:

2.0in;margin-bottom:.0001pt' wrap="">mention those books which you think is really worth purchasing

Binay Kumar
Oracle Cerified DBA

London

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___________________________________________________________________________<font

color=black> Received on Fri Feb 01 2002 - 05:20:49 CST