Re: How do a non unique index enforces primary key constraint?

From: hypermodern <faltoobd_at_yahoo.com>
Date: 26 Oct 2004 09:05:02 -0700
Message-ID: <fcefb078.0410260805.66d9f113@posting.google.com>

Thanks for the excellent replies, folks. Very much appreciated.

Fast Eddy

Mark.Powell_at_eds.com (Mark D Powell) wrote in message news:<2687bb95.0410201621.51793ba6_at_posting.google.com>...
> faltoobd_at_yahoo.com (hypermodern) wrote in message news:<fcefb078.0410201004.141d9d72_at_posting.google.com>...
> > Hi all
> > I am preparing for OCP. I have came across this in the student book
> > that a non-unique index can enforce a primary key constraint. I don't
> > get it. Can anybody explain this please.
> >
> > Thanks
> >
> > Fast Eddy
>
> See the Concepts manual chapter on Contraints. A non-unique index
> enables deferring enforment of the PK constraint until commit time. A
> unique index would prevent the insertion of a duplicate row at insert
> time.
>
> HTH -- Mark D Powell --
Received on Tue Oct 26 2004 - 11:05:02 CDT