Re: Problem with cache usage -> very bad performance?

ctcgag_at_hotmail.com writes:

> plm_at_gmx.li wrote:
> >
> > > > On a Solaris 8 with 8GB of ram and oracle 9i I run a query like this:
> > > >
> > > > select * from sometab p
> > > > where p.month='31-jan-2003'
> > > > and not exists (select 1 from sometab q where p.id=q.id and
> > > > q.month='31-dec-2002')
>
> Since the column is named "month" rather than "date", I'm asssuming
> everything is stored as the last day of their respective month, right?

Yes, it is monthly data, and (for historical reasons) we use each months last day to designate a month.

> Perhaps this is a dumb question, but shouldn't one of the numbers
> 476, 1, or 296 correspond to the estimated cardinality Jan-2003
> partition? None of them are even close to the 80,000 estimate.

Hmm, I have never really paid attention to the actual cardinality numbers, assuming they can only be used to compare two optimizer soluations relative to each other. Do these numbers have some absolute meaning?

-- 
Peter Mutsaers, Dübendorf, Switzerland.