Re: are hints still necessary in 9i?

I just read about Oracle 9i that there is something called a 'dynamic sampling feature'.

There is also a new view v$sql_plan.

Is it true that Oracle not only keeps the 'best' plan, but also some (how many?) others, and switches to another plan after it found out, after the first execution of this 'best' plan, it did not made the correct assumptions, for example because the information was missing?

Luc

"Connor McDonald" <connor_mcdonald_at_yahoo.com> wrote in message news:3F853AE4.3C0A_at_yahoo.com...
> Luc Gyselinck wrote:
> >
> > At every new release of Oracle, the CBO wil be enhanced, and thus
> > (hopefully) make better desicions. But it will never be perfect. You
will
> > always encounter situations where you will need a hint.
> >
> > I hope, one day, the CBO will 'learn' from it's 'mistakes' it made when
> > choosing the 'wrong' plan.
> >
> > "Ryan Gaffuri" <rgaffuri_at_cox.net> wrote in message
> > news:1efdad5b.0310080503.12cd6fc8_at_posting.google.com...
> > > Tom Kyte swears that if you properly analyze your table, the CBO is at
> > > the point where you never need hints. I find I still need them
> > > 'occasionally', though not very often.
> > >
> > > anyone else have opinions? anyone who beta tested 10g see an
> > > improvement in the CBO? IT tends to get a little better with each
> > > release.

>

>