Re: Pb with MERGE JOIN (CARTESIAN)

From: <sybrandb_at_yahoo.com>
Date: 2 Jan 2004 06:25:27 -0800
Message-ID: <a1d154f4.0401020625.60eeb66b@posting.google.com>

"zeb" <thierry.constant1.nospam_at_free.fr> wrote in message news:<3ff54f1a$0$1180$636a55ce_at_news.free.fr>...
> > Cure problems instead of fight symptoms.
> > Merge join cartesian usually means a join predicate is missing.
> >
>
> > Cure problems instead of fight symptoms.
> > Merge join cartesian usually means a join predicate is missing.
> >
> Are you sure ?
> Why if I decrease sort_area_size
> the MERGE JOIN CARTESIAN become a NESTED LOOPS ?
>
> Thanks

Because the nested loops becomes cheaper in terms of IO. Merge join cartesians are 'normal' only in 1 of 10000 cases. In all the other 9999 cases they point to a programming error.

Sybrand Bakker
Senior Oracle DBA Received on Fri Jan 02 2004 - 08:25:27 CST