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Re: index full scan over an index fast full scan in an analytic function?

From: Vladimir Begun <vladimir.begun_at_oracle.com>
Date: Thu, 23 Oct 2003 21:59:26 -0800
Message-ID: <F001.005D4248.20031023215926@fatcity.com>


Vladimir Begun wrote:

> Full scan 
> This is available if a predicate references one of the columns in the 
> index. The predicate does not need to be an index driver. Full scan

> is also available when there is no predicate, if all of the columns
> in the table referenced in the query are included in the index and at
> least one of the index columns is not null. Full scan can be used to
> eliminate a sort operation. It reads the blocks singly.

To avoid any confusion 'singly' here means "logically singly' -- in the reality (modern versions) it looks more like scattered read. Also this 'singly' depends on session settings.

-- 
Vladimir Begun
The statements and opinions expressed here are my own and
do not necessarily represent those of Oracle Corporation.

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Vladimir Begun
  INET: vladimir.begun_at_oracle.com

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Received on Fri Oct 24 2003 - 00:59:26 CDT

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