It depends, but remember hints are just that hints, not instructions.
Oracle reserves the right to use whatever it chooses, but I personally have
never seen oracle choose a different plan.
--
Robert Fazio, Oracle DBA
rfazio_at_home.com
remove nospam from reply address
http://24.8.218.197/
"Kenneth C Stahl" <BlueSax_at_Unforgettable.com> wrote in message
news:391AC373.CD8179A3_at_Unforgettable.com...
> Sybrand Bakker wrote:
> >
> > Gertjan <gr_at_compexbv.nl> schreef in berichtnieuws
> > 8fc67m$29j$1_at_porthos.nl.uu.net...
> > > In several messages I noticed that some of you are using optimizer
hints?
Is
> > > using these hits advisable? Some of my colleques have advised me NOT
to
use
> > > hints but to 'play around' with the were-clauses.
> > >
> > > Also, can anyone can give me some directions to sites or books that
explain
> > > hints???
> > >
> > > Thanx,
> > > Gertjan
> > >
> > >
> > The use of hints is a necessity as the perfect optimizer doesn't exist.
> > If you are using the cost based optimizer playing around with where
clauses
> > is not going to make much difference. It will work in the rule based
> > optimizer, which is still present in the software but has been obsoleted
> > officially with Oracle 7.1, way back in 1993 or 1994.
>
>
> So what about a situation like this. I'm about to start working with an
> application in which statistics have never been run. The developer who
> wrote the front end has embedded a lot of hints in his code to make the
> application work better. If I start running statistics will the
> execution plan for the sql which uses the hints change? Should I suggest
> to the developer that once I start running statistics that he drop the
> hints and see if he gets an execution plan that is better then what he
> was getting before with the hint?
Received on Thu May 11 2000 - 00:00:00 CDT
