Re: index skip scan

From: Jonathan Lewis <>
Date: Tue, 6 Jan 2009 23:18:06 -0000
Message-ID: <>

"Shakespeare" <> wrote in message news:4963cac3$0$187$
> what's the meaning of resc_io here? I googled but can not find any
> explanation for it. It might be a cause for Oracle to use the skip scan.
> It seems to go for plans with low resc_io... while googling I saw more
> examples of this behavior.
> Shakespeare

resc_io = resource cost for I/O.

Before CPU costing appeared, you had just resc and resp

(resp = response for parallel execution, which was (crudely speaking) resc / degree).


Jonathan Lewis

Author: Cost Based Oracle: Fundamentals

The Co-operative Oracle Users' FAQ
Received on Tue Jan 06 2009 - 17:18:06 CST

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