Re: The MySQL/PHP pair

"Dan" <guntermann_at_verizon.com> wrote in message news:E5lid.215$2c5.82_at_trnddc01...
>
> "Laconic2" <laconic2_at_comcast.net> wrote in message
> news:m8mdnekuD_WFwxTcRVn-3w_at_comcast.com...
> >
> > "Dan" <guntermann_at_verizon.com> wrote in message
> > news:Kg0id.6107$wP1.5011_at_trnddc09...
> >>
> >> "Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote in message
> >> news:cm93fd$g11$1_at_news.netins.net...
> >> > "erk" <eric.kaun_at_pnc.com> wrote in message
> >> > news:1099431388.630616.174500_at_f14g2000cwb.googlegroups.com...
> >>
> >>
> >> [snip]
> >> >
> >> > It makes sense to bring it up since I have yet to PROVE all of my
> >> > concerns.
> >> > I have proven, I think, that 1NF as currently implemented by most
> > software
> >> > developers (the old version of 1NF) has no mathematical basis.
> >>
> >> What is this proof, pray tell. I've asked for a demonstration already
> > where
> >> attributes of a relation are anything less than an elements in the
> >> mathematical or logical sense when operated upon by relational
operators.
> >>
> >
> > I think the following has been demonstrated beyond reasonable debate:
> >
> > That not all relations (or collections of relations) are in what Codd
> > called
> > "normal form" in the 1970 paper.
> > That some relations (or collections of relations) are in "normal form".
> > That Codd never claimed a mathematical basis for reuiring "normal form"
> > in
> > the relational data model.
> >
> > That what Codd called "first normal form" in the followup papers on
data
> > normalization (1972, 1973) is the same thing as nroaml form in the 1970
> > paper.
> >
> > That, in the only formal definition Codd ever gave of frist normal form
> > (called 1NF nowadays), atomicity of attribute values is an essential
part
> > of the definition.
> >
> > That the atomicity requirement of 1NF is not part of the formal
definition
> > of the term "relation" in mathematics.
> >
> > That Date revised the definition of 1NF so as to remove the atomicity
> > requirement. (don't know the year).
> > That this revision was based on the pragmatics of IT, not the
mathematics
> > of relations, since 1NF was not a requirement based on mathematics.
> >
> > I say all this as one who is NOT convinced of Dawn's opinion that 1NF (a
> > la
> > Codd) was an obstacle to greater progress through the 1080s and 1990s.
Or
> > of her opinion that database constraints are counterproductive or
> > submarginal.
> > These remain to be shown.
> >
> > But the fundamental question of whether mathematical relations hinge on
> > 1NF
> > a la Codd has been dealt with, as far as I can see.
>
> I'm glad there is closure in your mind. Unfortunately, I think this is a
> fundamental issue and I don't quite see it your way. Sorry, Laconic2. I
> should know better than argue with a guy who graduated from MIT (IIRC).
> Perhaps it is just a matter of interpretation. :-)
>
> >
> > My point is that we have an alternative to going around in circles,
> > debating
> > the same old issues with the same old arguments every time around.
> >
> I think the difference in opinions is this. I made an effort to use
nested
> relations, nested sets, complex objects, etc. in terms of a theoretical
> model and in terms of what is available as part of SQL99 implementations
> now. I tried to formulate the questions, use complex values as keys,
create
> and implement methods, enforce constraints, share common "encapsulated"
> data, etc. I've gone through the motions of trying to understand how
> predicate calculus, and by extension, relational calculus would manipulate
> such sub-elements.
>
> It was counterproductive in that it was overly complex and severely
lacking
> in expressiveness. Integrity couldn't be enforced to the same degree as
a
> "flat" relational model (i.e. RI from sub-elements to 1st order elements
> couldn't be declared or enforced). Optimisation was constrained and even
> sub-optimal. Logical queries did not always produce consistent results.
> The list goes on and on. When I stated in earlier conversations that we
> hadn't even scratched the surface in terms of issues, I was speaking from
> experience.
>
> For those of you who have actually gone through similar paces, I'd like to
> hear your stories. Perhaps they yielded more success. But, I'd rather
not
> hear about intuitive guesses about what might work because the feeling is
> that it might be more productive and because *one* of Codd's paper didn't
> have the explicit presecription, "thou shall not use complex attribute
> values," especially from people that haven't at least tried to either
> design, or at least use, such a system. This is not a set of statements
> directed at you by the way Laconic2; rather, just musing out loud.

I think we can guess to whom it is directed. I've got a full day ahead, but look forward to reply to this and yor previous post later. Good stuff in both. Cheers! --dawn

> Regards,
>
> Dan
>
>
Received on Thu Nov 04 2004 - 14:41:33 CET