Re: Relational Databases and Their Guts

"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message news:bdcmeg$cq8$1_at_gazette.almaden.ibm.com...
> "Bob Badour" <bbadour_at_golden.net> wrote in message
> news:yrjKa.505$My6.68419676_at_mantis.golden.net...
> [snip]
> > > Let me reword it as:
> > >
> > > The ability to interact with a [subset of a] database via any one
of
> > > multiple information equivalent[subset] database schemas defined to
the
> > RDBMS
> > >
> > >
> > > "base relations" are in the eye of the beholder.
> > >
> > > Logically, all equivalent schemas are equal, there is no requirement
to
> > make
> > > one more equal than the others by making it 'primary'. Other than each
> > user
> > > choosing one as their current schema that is.
> > >
> > > Physically, one schema will be picked as the basis for physical
> > > implementation. This schema can be called "base" if you wish, but
users
> > should
> > > not care.
> >
> > I still do not see how one will specify the information equivalent
schemas
> > without views. With updatable views, users should not care either.
> >
> > What is different from views in what you are suggesting?
> >
>
> Well obviously you use something (very) like views, it's just that you
need a
> bit of extra other stuff to enforce the information equivalence and enable
the
> switching.

Okay. What extra other stuff? And if we basically have views, why do we need to switch anything? Received on Wed Jun 25 2003 - 22:15:36 CEST