Re: Analysing SYS tables

From: Bob Withers <Bob.Withers_at_mci.com>
Date: 1997/12/08
Message-ID: <MPG.ef20c9567cf4f68989693@news.internetmci.com>#1/1

In article <669689$opm_at_hdxl16.telecom.ptt.nl>, g.r.s.deisz_at_ptttelecom. unisource.nl says...
> Hi all,
>
> Does someone have any experience using the cost-based optimiser to access
> tables owned by SYS?
> Oracle Support advises not to analyse SYS tables in order to make sure the
> rule based optimiser will be used accessing these tables.
> Does this mean that Oracle has not been able to make the cost based optimiser
> good enough to guarantee performance?
>

No, it means that the SYS tables have been tuned for the rule based optimizer and using the cost based optimizer on them would, at best, give equal performance and would probably degrade performance.

Bob Received on Mon Dec 08 1997 - 00:00:00 CST