Re: system statistics

From: Thomas Kyte <thomas.kyte_at_oracle.com>
Date: 9 Oct 2003 08:22:23 -0700
Message-ID: <7b0834a8.0310090722.7512c04@posting.google.com>

Richard Kuhler <noone_at_nowhere.com> wrote in message news:<ROXgb.2708$Z86.2251_at_twister.socal.rr.com>...
> I'm reading "Effective Oracle by Design" by Thomas Kyte. He seems to be
> advocating using GATHER_SYSTEM_STATS _instead_of_ tuning
> OPTIMIZER_INDEX_CACHING and OPTIMIZER_INDEX_COST_ADJ directly. I can't
> find anything in the Oracle documentation that suggests that the
> presence of system statistics causes the optimizer to ignore the other
> settings. While I intend to do some experimentation, I'm wondering if
> anyone can make a definitive statement in this regard. Or, am I just
> misinterpreting the passage?
>
> Anyone have an opinion or real world experience to share on this?

well -- 'instead of tuning' doesn't mean 'oracle will ignore these'.

What I was saying was that you might well discover you don't need to tweak them, if you have good system statistics.

As Jonathan Lewis said in another followup - they are still "obeyed", still used.

sorry for the confusion, i'll relook at that text for a possible edit. thanks Received on Thu Oct 09 2003 - 10:22:23 CDT