Re: Lucid statement of the MV vs RM position?

David Cressey wrote:
> "dawn" <dawnwolthuis_at_gmail.com> wrote in message
> news:1146520667.985982.314140_at_y43g2000cwc.googlegroups.com...
>
> > So, I think we talked past each other on that one. If RVAs and other
> > non-1NF structures are now accepted in theory and implemented in
> > practice, then when should they be used? In theory (since I don't know
> > in practice with SQL-DBMS's), there are some good times to model in
> > NF2, I would think.
>
> Could you be a little more specific about what it is that you do not know,
> in the above?

There are some good and bad practices for including multi-valued attributes in a logical data model when implementing in various NF2 databases. Now that SQL-DBMS's include NF2 structures (RVAs + UDTs), what are the best practices for an LDM to include such? I've seen examples, but also read how it is rarely a good idea to use an RVA in a typical business scenario. So I do not know when, in practice, one should model with nested relations (for example),. What are practitioners learning or being told about changes in logical data modeling now that nested relations are viable?

The theory is not constrained by whatever issues the implementations might have, so my question was: when, in theory, should you model data with nested relations?

Thanks. --dawn Received on Tue May 02 2006 - 15:01:36 CEST