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Re: Count(*) not doing a FTS??

From: Wolfgang Breitling <breitliw_at_centrexcc.com>
Date: Thu, 2 Sep 2004 11:52:34 -0700
Message-ID: <1094151154.41376bf2ae5ec@webmail.hosting.telus.net>


AFAIK the segment header does not have a row count, only the number of blocks below hwm. But on the matter of count(*) not doing a FTS, that is correct. Oracle will use an index when possible.

Quoting rjamya <rjamya_at_gmail.com>:

> I am sitting in a class and instructor told us that count(*) reads
> rowcount from segment header in some (or most?) cases rather than
> doign the good ol' FTS. He can't remember exact details, so this email
> ....
>
> is it true? Which version was this introduced? Someone has a
> reproducible test case?
>
> Thanks in advance
> Raj
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-- 
regards

Wolfgang Breitling
Oracle 7,8,8i,9i OCP DBA
Centrex Consulting Corporation
www.centrexcc.com

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Received on Thu Sep 02 2004 - 19:15:56 CDT

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