Re: Can we solve this -- NFNF and non-1NF at Loggerheads

"Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote in message news:cu40to$ck1$1_at_news.netins.net...

> "Alan" <not.me_at_rcn.com> wrote in message 
> news:36lbt1F50dlt4U1_at_individual.net...

>
> I apologize for your frustration, Alan.  Perhaps you should read Date 
> and/or Darwin's current works so you can see where both Alfredo and I are 
> getting the idea that 1NF has been redefined by Date and his followers. 
> You should be able to find plenty on dbdebunk.com related to 1NF.  Not 
> everyone in the relational world follows Date's lead on such matters, but 
> many do, so you might want to read up.
>

Hi,

I must admit that I am very uncomfortable with the situation of someone taking ownership and redefining an aspect of someone else's model. Date and Codd did not always agree on "the model". For example, see http://www.dbdebunk.com/page/page/1706814.htm.

For me personally, I recognize the possibilities of RVA's as an extended model (or alternative one) and I am open to it, but I still have some serious concerns about the implications of an RVA-based or NFNF relational model. This does not say that such models are invalid, but rather that the model introduces some complexities and implications that I haven't fully worked out yet. Now, without making any presuppositions and speaking in the most general sense, more complexity for the same amount of expressibility and power is generally not a good trade-off. Until that time where I can fully understand and appreciate the implications, I will rather continue to feel more comfortable with a model that adheres and comforms to a uniform and consistent expressiveness of first order logic without special "safety" rules being necessary, particularly in the domain of relational tuple calculus.

Date often speaks of models in terms of structure, manipulative aspects, and integrity (this is the one the produces the most concern for me with RVA's). Or rather, he regards these three items the essential components of model specification. I personally think that all three aspects are modified in some degree from Codd's original model with this new "1NF" (e.g. RVA, nest and unnest, and who knows what else with n-order traversals of nesting levels with foreign keys). Therefore, I think this extension is a model that is separate and discernable one, not one that "redefines" and supercedes the original. If I understand you Dawn, this is the point you are making. Don't redefine 1NF, call Date's model something else.

Everyone won't agree with this particular opinion of course. I can accept that.

• Dan