Re: why does CBO not use available indices

From: Volker Hetzer <volker.hetzer_at_ieee.org>
Date: Mon, 13 Oct 2003 13:22:10 +0200
Message-ID: <bme1t3$r22$1@news.fujitsu-siemens.com>

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> schrieb im Newsbeitrag news:bm8b47$52f$1$8300dec7_at_news.demon.co.uk...
> The optimizer operates under several misconceptions:
> a) A single block read costs as much as a multiblock read
> (addressed by optimizer_index_cost_adj, partly)
Is there anything on otn or metalink that makes this more clear? I mean, in theory, the RAID system reads in at least one stripe, right?
I was guessing (probably wrong) that any read below db_file_multiblock_read_count costs the same?

Lots of Greetings!
Volker Received on Mon Oct 13 2003 - 06:22:10 CDT