Re: 3vl 2vl and NULL

From: David Cressey <>
Date: Fri, 17 Feb 2006 13:03:22 GMT
Message-ID: <uQjJf.5798$0s.4800_at_trndny04>

"Marshall Spight" <> wrote in

> Okay, bad phrasing on your part then. "Normalization" is the entirety
> of a bunch of things, 1NF being the weakest of them. So to communicate
> this concept, you shouldn't say you're against normalization. You
> should say instead that you favor nested structure. Note that this
> is not incompatible with relational algebra, although it does introduce
> challenges.
Any phrasing in this discussion has down sides.

A few years ago, Dawn discussed the same concept under the term "non first normal form". This phrasing sounds correct to me. But it ran afoul of the following problem: 1NF has two definitions, depending on whether you follow Codd's original formulation of the normal forms, or whether you follow Date's reformulation of 1NF. According to the folks that cite Date, Date discovered that Codd's original definition of 1NF was "incorrect". I don't know how one determines that definitions are "incorrect".

Anyway, to make a long story short, Dawn decided, in her opening statement in her blog, to use the term "normalization" to mean what it meant in the Codd 1970 paper, what Codd and others later called "first normal form". This phrasing has a down side. But, as I've said, so do all the others.

I'd like to see the discussion move forward, rather than get derailed, once again, by terminology pitfalls. As I've said, I remain very skeptical of Dawn's proposition. I understand that proposition to be that normalization (meaning getting rid of repeating groups by decomposition) does more harm than good. I don't believe it. BTW, I haven't visited the blog for about a month, so maybe the monologue is moving forward over there.

> Okay, non-1NF is one thing. "Ordered lists" is redundant; just say
> "lists". Lists is a second thing. 2VL is a third thing. This is a good
> list; it is specific. But above you said "I'm trying to convince
> 'the industry' to adopt more flexible (dare I say 'agile') data models"
> but then you followed it up with an entirely unrelated list of desired
> features. Nothing about nested relations, lists, and 2VL says "agile".
> Probably you should drop the "agile" and focus instead on the specific
> additional capabilities you want. This would be more concrete. It
> would give your reader a clearer idea of what you are thinking.

Good analysis. Received on Fri Feb 17 2006 - 14:03:22 CET

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