Re: Stored fields ordered left to right
Date: Sun, 28 Dec 2003 08:53:51 -0600
"Bob Badour" <bbadour_at_golden.net> wrote in message
For anyone who doesn't know, ignore Dawn--she's an idiot. Mathematical
> relations do not have any particular attribute order. The physical
> representation of mathematical relations using written symbols on planar
> surfaces relies on physical order for succinctness.
Your opinions about relations are welcome, but please refrain from telling me again what an idiot I am as I know your opinion already. If you want others to join you in thinking I'm an idiot, use logic to indicate the error of my thinking rather than telling people they ought to ignore me. Thankfully, I can summon up the self-esteem to continue discussing in this forum. I wonder how many people you have bullied or offended enough to leave OR decided this list was not about rational thinking, but rather personal attacks.
As for mathematical relations, they ARE sets of ORDERED TUPLES, whether on paper or in concept. The ordering is important for mapping to the domains, however, it is the case as one person pointed out that with database relations as laid out by Codd, there is a simple mapping from those relations to mathematical relations. There is still a vocabulary problem when working with database models that did not stem from Codd and that DO have actual mathematical relations in their model. "Relational Database" is not a useful designation when both DB2 and U2 have this applied to them. They are based on two very different models.
As someone once said (googling it indicates it was George Box?) "All models are flawed, but some are useful". The "relational database model" has pros and cons. The Nelson-Pick model has pros and cons. The XML model (very similar to the Nelson-Pick model) has pros and cons. One of the advantages of the relational model is that it has a wealth of documentation spelling it out as a logical theory. Almost everything written about the Nelson-Pick model is directed to the implementations (PICK) rather than the abstracted logical model. I'm attempting to provide more of an abstracted model so that the pros and cons of the model and not just the implementations can be discussed. I am guessing that most on this list are big fans of the relational database model, while I prefer other models. I think that is what leads Bob to his false conclusion.
--dawn Received on Sun Dec 28 2003 - 15:53:51 CET