RE: No primary keys

I heard somewhere that enterprise data replication might require that all tables involved to have primary keys. Anybody know if that's true? Con Woodall Colorado State University Veterinary Teaching Hospital Computer Services cwoodall@vth.colostate.edu 970-491-1244 On Tue, 9 Jan 2001, Parker, Jack wrote: > > An excellent point. One great way to improve DSS performance is to drop > indices - that may include PKs. > > cheers > j. > > > -----Original Message----- > > From: cedarsiding@my-deja.com [mailto:cedarsiding@my-deja.com] > > Sent: Monday, January 08, 2001 6:07 PM > > To: informix-list@iiug.org > > Subject: Re: No primary keys > > > > > > > > > you can't even > > > use referencial constraint (foreign keys) between your tables if you > > do > > > not have primary keys on them. > > > > Child tables need no primary key, only parent tables do. > > > > > > > That's why it's strongly recommendated that all tables in your > > database > > > model must have a defined primary key. > > > > I don't think this is valid generic advice. One should consider > > whether one needs something before using it, because it does > > have a cost in both disk space and performance. > > > > Primary keys are often vital in "operational" systems, > > i.e. OLTP or ODS (operational data store) applications. > > Some DSS applications do not need them, or at least not > > on all tables. > > > > -cs > > > > > > Sent via Deja.com > > http://www.deja.com/ > > >