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Re: Cache Hit Ratio from system views

From: DA Morgan <>
Date: Fri, 07 Sep 2007 17:13:58 -0700
Message-ID: <>

Bob Jones wrote:

>> To quote the Oracle docs:
>> "A low cache hit ratio does not imply that increasing the size of the 
>> cache would be beneficial for performance. A good cache hit ratio could 
>> wrongly indicate that the cache is adequately sized for the workload."

> Finally, something useful, but quoted from the doc. Notice the words like
> "could" or "would"?
> The second sentence is a little vague. What does "good" mean? Is my cache
> still too small, if BCHR is 99%?

You have been challenged repeatedly to put up a test case that supports your position. Either you don't have SQL*Plus or don't know how to use it? I wonder which?

You are in no position to criticize anyone or anything. Especially Oracle docs for vagueness. So far the only thing you've done with clarity is define your lack of expertise on the subject.

>> BHCR is as worthless as your unwillingness to acknowledge you are wrong.

> I take it our buddy Dan here doesn't tune his buffer cache.

No. You should take it that he doesn't use worthless metrics to do so.

>> But given that your name is in valid, and your email is not valid, why
>> would anyone expect your opinion to be valid? Come on out of the closet.

> It appears valid names are more important to you than valid arguments.

Wrong again: You have neither.

I wonder ... why would someone at San Diego State be so afraid to acknowledge who they are? Perhaps some more research will answer that question.

Daniel A. Morgan
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Fri Sep 07 2007 - 19:13:58 CDT

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