Re: Optimizer, Cartesian Product & Extraneous Table

Gert Rijs wrote:
>
> The extra table *is* being used: to create a cartesian product.
> How could the optimizer (or better, the parser) know that it isn't your
> intention?
> --

I was wondering about the same, and thought it would be nice to at least give a warning message, when the extra table is neither used in your where clauses nor in the select. I mean, what would be an example when one would intend to do that?

Christian
> Dr. J. Sylvan Katz <jskatz_at_coombs.anu.edu.au> wrote in article
> <35501E15.4CCF162E_at_coombs.anu.edu.au>...
> > Can someone please explain why a cartesian product is produced if an
> > extraneous table name is accidently put in the from clause? Can't the
> > optimizer determine that the table is not being used?
> >
> > Regards
> > Sylvan
> >
> >
Received on Wed May 06 1998 - 08:46:11 CDT