RE: Oracle Tunning

[K Gopalakrishnan]

Continuing my previous mail :   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   The one is dated 9th December 1999;   Here is the excerpt:   Topic :Free buffers  9 December 1999   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%.    A: The advice that free buffers should be available after a certain period is wrong prior to 8.1, and dubious for 8.1.        Best Regards, K Gopalakrishnan       -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of SARKAR, Samir Sent: Friday, February 01, 2002 2:25 AM To: Multiple recipients of list ORACLE-L Subject: RE: Oracle Tunning   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 Samir Sarkar Oracle DBA - Lennon Team SchlumbergerSema Email :  [EMAIL PROTECTED]             [EMAIL PROTECTED] Phone : +44 (0) 115 - 957 6217 EPABX : +44 (0) 115 - 957 6418 Ext. 76217 Fax : +44 (0) 115 - 957 6018            -----Original Message----- From: Mogens N�rgaard [mailto:[EMAIL PROTECTED]] 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: 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, [EMAIL PROTECTED] wrote: Hi Everyone        Can anyone suggest me some very good book on Oracle Tunning. Please only mention those books  which you think is really worth purchasing Binay Kumar Oracle Cerified DBA London ------------------------------------------------------------------- The contents of this e-mail are confidential to the ordinary user of the e-mail address to which it was addressed and may also be privileged. If you are not the addressee of this e-mail you should not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. If you have received this e-mail in error please notify us by telephone or e-mail the sender by replying to this message, and then delete this e-mail and other copies of it from your computer system. Thank you. We reserve the right to monitor all e-mail communications through our network.   ___________________________________________________________________________ This email is confidential and intended solely for the use of the individual to whom it is addressed. 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