Re: Migrating to cost based optimizer

> hasta_l3_at_hotmail.com wrote:
>
> > BTW, we have exactly zero experience with CBO :-)
>
> Then let me make a recommendation.
>
> Spend a lot of time learning how DBMS_STATS works.
> Be sure you check out the collection of system statistics,
> dictionary statistics, and how to fool Oracle into believing
> things about objects that are not true, today, but may well
> be true, tomorrow.

Thanks, Daniel.

I suppose it would make sense to collect the statistics of representative customer, and fool the database we use when developping with these stats. Is it right ?

Let's call them the canonical stats.

Which strategy would you recommand for new customers, whose database is initially empty (and who dont have a dba available on site) ?

• Automatically collect the local customer statistics periodically ?
• Start with the canonical stats, then switch to an automatic collection when the site has reached a data size treshold (to be defined)
• Never compute stats automatically. Keep the canonical stats till there is a problem.
• Anything else ?