Re: Oracle Hints

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.

The hints are described in the Oracle docs, likely in the performance tuning guide. All docs are available at http://technet.oracle.com. They are definitely also in the tuning book of Rich Niemic, published by Osborne/Oracle Press.

Hth,

Sybrand Bakker, Oracle DBA Received on Wed May 10 2000 - 00:00:00 CDT