Re: Query Performance.

Brian,

Check out Chapter 5, Using EXPLAIN PLAN from Oracle8i Designing and Tuning for Performance. You can find this at http://technet.oracle.com/docs/products/oracle8i/doc_library/817_doc/server.817/a76992/ch13_exp.htm#822

HTH,
Brian

Brian Tkatch wrote:
>
> On Tue, 23 Jan 2001 14:10:05 GMT, Brian Peasland
> <peasland_at_edcmail.cr.usgs.gov> wrote:
>
> >> I am curious to know why adding extra things to the query (I.E. The
> >> view) shaved off 3 to 4 seconds.
> >
> >You'll answer your own question, and learn a lot about query
> >optimization if you check out the EXPLAIN PLAN of the original query and
> >the modified query. There could be a couple of reasons why the query
> >executed faster.
> > 1) Adding the "extra things" caused the optimizer to use an index.
> >This sped up the query.
> > 2) Adding the "extra things" caused the optimizer to *NOT* use an
> >index. This sped up the query.
> >
> >These aren't the only reasons. Without seeing the EXPLAIN PLANs, it's
> >hard for anyone to say as everything else is pure speculation.
> How do I get an explain plan? Or at least, where is is explained in
> the docs?
>
> Brian
 

-- 
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Brian Peasland
Raytheons Systems at
  USGS EROS Data Center
These opinions are my own and do not
necessarily reflect the opinions of my 
company!
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