Re: Nulls, integrity, the closed world assumption and events

Walt wrote:
> "dawn" <dawnwolthuis_at_gmail.com> wrote in message
> news:1168882079.488314.138100_at_51g2000cwl.googlegroups.com...
> > Walt wrote:
> > > "dawn" <dawnwolthuis_at_gmail.com> wrote in message
> > > news:1168831761.571396.308030_at_11g2000cwr.googlegroups.com...
> > > > Marshall wrote:
> > > > <snip>
> > > > > Sure. And since you are of the opinion that theory can steer us down
> > > > > the wrong path, and since you regularly deprecate relational theory
> > > > > but do not provide an alternative *theory*, I wonder at your
> presence
> > > > > in a theory newsgroup.
> > > >
> > > > If I had another comprehensive theory, I would not have so many
> > > > questions or opinions that I want to pass by those who can correct me.
> > >
> > > No one can correct you.
> >
> > Many have, Walt, but thanks for the thought.

>

Could you point me to proof that something I expound is incorrect? Perhaps just starting by telling me what I think to be true that you think false, or vice versa, would be helpful. I would very much appreciate knowing.

Are those who develop the products whose data model I prefer, such as IBM U2, Intersystems Cache', jBASE, Revelation, OpenQM..., all also incorrect in their understanding? What about the IBM DB2 9 developers?  Do they have the data model right?

I started with two issues I wanted to investigate, where all of those using "relational databases" modeled data differently than those of us with "legacy databases." I had worked with both approaches and was coming to the conclusion that the old stuff did some things a lot better than the new (although the new tools were all swoopier with typically more features). 1) 1NF vs NF2 and 2) NULL handling, 3VL vs 2VL. Now that I see that the state of the research in the RM has many people agreeing that relation-valued attributes are acceptable and 2VL is preferred, I figured I was more in the majority than I had previously known, although most SQL-DBMS products are not yet up to speed.

I added in the issue of lists. Although RVAs are accepted by some, lists are not yet as accepted in the theory other than treating them as user-defined types (not incorporated into query languages, as best I can tell). I'm still in the minority on that one, it seems, but I'm guessing that the RM will catch up with MV on that one at some point too.

While it is now clear to me that NF2, 2VL, and lists are desirable (when I started asking about them, I thought I would be convinced to abandon them by listening to the theory experts), issues about strong vs duck vs weak typing are less clear to me, along with metadata specifications and constraints in general. I lean toward the DBMS doing minimal typing, with services that maintain the DBMS handling constraints. I'm guessing I'm still in the minority on that one, but surely this is not an argument where I stand alone as there have been discussions about typing with every computer language. Java and JavaScript each have their charm and their problems in this area.

> I doubt that there is enough information in the world to change your mind.

I have changed my mind on a lot of things since posting here originally. But so far you are right that I haven't seen the proof that I should want to move from NF2 to 1NF (or the form-formerly-known-as-1NF) nor from 2VL to 3VL. It even appears that the industry is headed in my direction, don't you think?

Is there something you KNOW to be true and can prove that you think that I do not believe to be true? If so, I would be happy to read about it. I would prefer that I not be missing something that is perfectly clear to everyone else. Thanks Walt. --dawn

> > What about you? Have you learned anything from this forum or did you
> > know everything coming into it? --dawn
> Oh yeah, I've learned things.
> >
Received on Tue Jan 16 2007 - 17:58:46 CET