RE: BITMAP index cost 10053 trace

From: Barr, Stephen <Stephen.Barr_at_BSkyB.com>
Date: Tue, 24 May 2005 14:37:17 +0100
Message-ID: <4127F81F6CAFC245A18BC49054EFB06301D6E249@ssslexchusr6.sssl.bskyb.com>

Is the formula available anywhere?

-----Original Message-----
From: Wolfgang Breitling [mailto:breitliw_at_centrexcc.com] Sent: 24 May 2005 12:26
To: Stephen.Barr_at_BSkyB.com
Cc: oracle-l_at_freelists.org
Subject: Re: BITMAP index cost 10053 trace

At 02:33 AM 5/24/2005, Barr, Stephen wrote:
>I'm trying to resolve how the CBO has come up with the cost of 9131 in the
>10053 extract below.
>
>
>If the formula is blevel + FF*leaf_blocks + FF*clustering_factor then the
>cost comes out as 11 - how does it then jump to 9131? I'm assuming the cost
>calculationfor bitmap indexes is very different?

I'm assuming you are right. :-)

Regards

Wolfgang Breitling
Centrex Consulting Corporation
www.centrexcc.com

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Received on Tue May 24 2005 - 09:42:43 CDT