Re: foundations of relational theory?

"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message news:bn15ap$g1a$1_at_gazette.almaden.ibm.com...
> "Dawn M. Wolthuis" <dwolt_at_iserv.net> wrote in message
> news:6db906b2.0310191644.13b47642_at_posting.google.com...
> [snip]
> > While this is not an academic statement of why PICK works nicely, it
> > might give some hints on why folks who have put their dollars into the
> > SQL-based RDBMS world can become born-again when they see the
> > difference in dollars needed for a comparable PICK system.
>
> Mind if I take it as an academic statement?, and use it to give hints at
why
> an MV system will be less useful than a relational system everything else
> being equal.
>
> > Again, it is not that PICK is flawless (by any stretch), but as a
> > basis for moving forward, I'd sure rather start with this big bang for
> > the buck implementation than any SQL-based RDBMS I've seen. And, yes,
> > I know this is a theory forum and not necessarily for opinions based
> > on practice, so I'll go back to the claim, even though not fleshed
> > out, that persisting data based on language -- such as modeling entire
> > propositions together rather than piecing them apart to the extent
> > done in an RDBMS -- makes sense because we are not trying to persist
> > mathematical relations ultimately -- we are trying to persist
> > propositions.
>
> Guess what, "trying to persit propostions" is *exactly* what the
relational
> model is all about. A tuple (row) is a fact - a proposition.
>
> > For example, "Jane Doe has three kids -- John, George, & Paul -- and
> > also three cars -- a 1967 Mustang Fastback and a 1968 VW Bug, but the
> > car she usually drives is her other car -- a 2002 Ford Thunderbird".
> > A lousy sentence, but easy to image on a form. This sentence/form is
> > about a single person -- Jane Doe
>
> Any why, prey, is that sentence not also about the person John (or George
or
> Paul)? Or equally it is not about 2002 Ford Thunderbirds?

You forgot to ask Dawn for the queries:
Who has kids John and Paul?
Who has a kid whose name contains John and Paul? Received on Mon Oct 20 2003 - 20:27:04 CEST