RE: how to set optimizer_index_cost_adj and cache parameters?

From: <oracle-l-bounce_at_freelists.org>
Date: Fri, 26 Mar 2004 12:51:26 -0500
Message-ID: <D91D9D5A73FC694BBC52F1EB26AD410F024120D0@MSGBOSCLD2WIN.DMN1.FMR.COM>

Hi Jonathan,

This is from the article:
"Essentially, this formula tells Oracle the number of block visits (see side bar) that a process will have to make to collect all the data from the table. If the selectivity (fraction of the table's data) is X, then it seems reasonable that the number of index leaf blocks to visit will be X% of the clustering_factor; and the number of table block visits will also be X%. Add on the fact that you have to walk from the root to the leaf level just once, and you have the formula."

I believe it's the other way around:

the number of index leaf blocks = X% of leaf blocks the number of table block visits = X% of clustering_factor

Regards,

Waleed

-----Original Message-----

From: Khedr, Waleed
Sent: Thursday, March 25, 2004 12:23 PM
To: 'oracle-l_at_freelists.org'
Subject: RE: how to set optimizer_index_cost_adj and cache parameters?

Good article.

Regards,

Waleed

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Received on Fri Mar 26 2004 - 11:48:04 CST