Re: Tarski school influence on Database Theory

Dana ponedjeljak, 28. rujna 2015. u 09:40:04 UTC+2, korisnik Eric napisao je:
> On 2015-09-25, vldm10 <vldm10_at_yahoo.com> wrote:
> > On Monday, July 20, 2015 at 16:09:59 PM UTC-7, compdb <compdb_at_hotmail.com> wrote:
> >> Besides inventing relational algebra, Codd also initiated and championed
> >> query safety, integrity, normal forms and other issues involving
> >> application of relational algebra to database management, ie the
> >> relational model. What really would have helped the database field but
> >> that *didn't* happen is if people had paid more attention to what Codd
> >> was saying about being relational.
> >>
> >> philip
> >
> > (i) Relational Algebra.
> > I agree that Codd invented relational algebra.
> >
> > (ii)
> > Integrity and normal forms. Regarding the normal forms, I must say that
> > Codd did not invent the "First normal form." As a novice programmer, I
> > had the opportunity to witness conflicts among senior project managers,
> > that are on this topic. Project managers from one group have used variable
> > length of the records, and project managers from another group have used
> > records that have a fixed length (that is, they were working with the
> > first normal form). In both cases, I had the chance to see a very good,
> > very complex and very interesting solutions.
> > So the idea of "First normal form" was performed and analyzed in detail
> > before Codd. All the advantages and disadvantages of "First Normal Form"
> > were well analyzed in very complex cases. Note that variable length of
> > records and entities, we can not apply to relations.
> >
> > It is not true that Codd invented the "First normal form". Codd added
> > "First normal form" to relational model, and he gave the name: "The
> > first normal form"
>
> Fixed length records can not possibly be the same as first normal form
> since records are about files and first normal form is about relations.
> However, I can not see at all how they are even in any way similar to
> first normal form. So what on earth are you talking about?
>
> Eric
> --
> ms fnd in a lbry

Have you ever worked with programming languages? If so, have you worked with  complex data structures by using complex files?

Vladimir Odrljin Received on Mon Sep 28 2015 - 22:07:04 CEST