RE: *****SPAM***** RE: Any performance benefits in going to db_16k_cache_size or db_32k_cache_size

From: Hameed, Amir <Amir.Hameed_at_xerox.com>
Date: Wed, 10 Jan 2007 11:51:14 -0500
Message-ID: <77A4D80DB2ADD74EB5D7F1D31626F0C0038A7CD3@usa0300ms03.na.xerox.net>

For those who are running 11i suite, multiple block sizes are not supported by Oracle support and they will make a big stink if you try to change it even if made perfect sense to you. We tried to make a change for one table when we were implementing RAC based upon recommendations from Steve Adams but Oracle's 11i performance group pushed back really hard and stated that if we did that then we would not be supported.

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        From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Tanel Poder

	Sent: Wednesday, January 10, 2007 11:36 AM
	To: cary.millsap_at_hotsos.com; mark.powell_at_eds.com;
oracle-l_at_freelists.org
	Subject: *****SPAM***** RE: Any performance benefits in going to

db_16k_cache_size or db_32k_cache_size                  

        Yeah, I agree with Cary and Mark and would add a comment that a tricky thing like changing block size (thinking about granularity of buffer locking) should be tested with simulating real concurrency.          

        E.g. your single session index lookup might run faster due lower index height, but on the other hand you could have more buffer busy waits in high-concurrency environments, etc..                    

        Tanel.                  

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                From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Cary Millsap

		Sent: Thursday, January 11, 2007 00:13
		To: mark.powell_at_eds.com; oracle-l_at_freelists.org
		Subject: RE: Any performance benefits in going to

db_16k_cache_size or db_32k_cache_size                                  

                I have the same opinion as the one Mark describes here.                  

                One more comment: Why guess, when you can KNOW.                  

                If you need to know, test it, and measure the performance.                                    

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Received on Wed Jan 10 2007 - 10:51:14 CST