Re: VAT rate or VAT amount as a column?

"Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message news:x6mBg.35726$pu3.465238_at_ursa-nb00s0.nbnet.nb.ca...
> David Cressey wrote:
>
> > "Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message
> > news:aVlBg.35723$pu3.465389_at_ursa-nb00s0.nbnet.nb.ca...
> >
> >>Emily Jones wrote:
> >>
> >>>A view isn't the same as a base table though is it? Materialised or
not.
> >>
> >>No, a view, by definition, is not a base table. The base tables provide
> >>the raw (logical) material from which we construct application views.
> >>While each application might view the database as a normalized set of
> >>relations, the union of the application views and the base tables
> >>generally won't be normalized and will have considerable redundancy.
> >>
> >>While views are derived from the base tables, though, the base tables
> >>are themselves derived from physical storage. Thus it is conceivable
> >>that an attribute in a base table will be derived from other stored
> >>attributes rather than physically stored itself. That's generally not
> >>possible with available SQL dbmses at this time.
> >
> > I'm not sure I understand the above.
> >
> > Interbase has a feature called a "computed by" column. Such a column is
not
> > stored, but is materialied on demand.
> > Is this an example of what you are talking about?
>
> It could be. I am not familiar enough with Interbase to say with any
> confidence.

Neither am I. I'm trying to teach myself Firebird, for reasons best left unsaid. As part of that, I'm reading some Interbase DOCS. Received on Mon Aug 07 2006 - 13:49:29 CEST