Re: Stored fields ordered left to right
Date: Tue, 13 Jan 2004 01:56:12 -0600
Message-ID: <slrnc0794s.3b7.adrian_at_sixfingeredman.net>
Marshall Spight <mspight_at_dnai.com> schrieb:
>> A modelling tool should deliver a straightforward mapping between the
>> parts of the model and the parts of the system we're modeling. With
>> relations it is easy to make such a mapping by treating relations as
>> logical predicates: "so-and-so LIVES AT such-and-such-a-place". I don't
>> see how such a mapping would work in general for functions.
>
> It's the *exact* *same* *mapping.* The only difference is that you
> are limited to a single key.
It can't be the same mapping, as proven by example; the 3-part predicate "person LIVES AT place DURING time period" has an obvious mapping to the columns of a relation. To which parts of this predicate do the DOMAIN and RANGE of a function correspond? Received on Tue Jan 13 2004 - 08:56:12 CET