Re: New Feature: "Cost Based Transformation"

From: <mccmx_at_hotmail.com>
Date: 5 Sep 2005 00:57:53 -0700
Message-ID: <1125907073.364673.91170@g49g2000cwa.googlegroups.com>

Mark,

I've just read through the article... Its a good introduction but it seems to be innaccurate in places. For example some of the defaults for init.ora parameters are incorrect (i.e. statistics_level does not default to ALL in 9i).

Also the table on transformations appears to be incorrect too.... I logged a call with Oracle support about subquery unnesting and as part of that TAR resolution we confirmed that subquery unnesting is actually costed in 10g.

I have ended up logging another TAR for this problem. The support Analyst is filing a bug. I'm starting to get a bit frustrated with the amount of optimizer bugs I've hit over the last 6 months. This really surprises me because we run on relatively up to date patches levels of our DB software (8.1.7.4, 9.2.0.6, and 10.1.0.4)

Thanks for the feedback.

Matt Received on Mon Sep 05 2005 - 02:57:53 CDT