Re: analyze index

From: Richard Foote <richard.foote_at_bigpond.nospam.com>
Date: Tue, 25 Jan 2005 08:59:50 GMT
Message-ID: <aUnJd.133397$K7.81835@news-server.bigpond.net.au>

"Holger Baer" <holger.baer_at_science-computing.de> wrote in message news:ct4udr$d3p$1_at_news.BelWue.DE...
> Oradba Linux wrote:
>> Why would analyze index command read table segments?
>>
>>
>
> Because it has to?
>
> Or how should it be able to determine the clustering_factor?
>

Hi Holger

Actually, it doesn't need to visit the table in order to calculate the CF as it has all the info it needs within the rowids contained in the index.

Basically, as it reads through the rowids in the leaf pages, if the block id (or of course file no) changes from one index entry to the next, the CF is incremented. If consecutive index entries point to the same block, the CF is not incremented.

Cheers

Richard Received on Tue Jan 25 2005 - 02:59:50 CST