Re: Natural keys vs Aritficial Keys

From: David BL <>
Date: Fri, 29 May 2009 11:52:08 -0700 (PDT)
Message-ID: <>

On May 29, 11:04 pm, paul c <> wrote:
> David BL wrote:
> > On May 29, 9:53 pm, paul c <> wrote:
> >> David BL wrote:
> >> ...
> >>> I have no idea what you mean by "relvars are structures (not logical
> >>> pointers presumably?". Please quote me rather than pretend to quote
> >>> me.
> >> > "... However with other ways of
> >> >> composing data structures, sub-variables may not exist. A relvar is
> >> >> one such example. ..."
> >> ...
> >> There's your quote for the second time.
> > Good that's better. When I talk about composing data structures I'm
> > speaking informally. If I wanted to be more precise I might talk
> > about the way values can compose, or types can compose, or perhaps
> > even see whether it's possible to formalise an idea that variables
> > compose.
> > Now, what is your point?
> Until you start being more precise, you will continue to go 'round in
> circles, mixing up concepts and losing the essential ones

I'm sorry you think that. Are you being genuine? So far your comments suggest you've made very little effort to understand my posts. In fact I find them rather amusing! You've ignored my responses and appear to emphasise a very informal and insignificant "commentary" portion of my posts as evidence of imprecision. I don't know whether it's because you're being insincere or whether you didn't comprehend my post sufficiently to make a credible criticism, or maybe something else I'm not aware of. I also wonder at your suggestion that I'm "going round in circles, mixing up concepts and losing the essential ones". That's quite a thing to say! So please tell me, where exactly am I going around in circles? Exactly what concepts am I mixing up?

When you said the idea of sub-variables is mysterious, I thought that's great because my main interest in posting was to see whether the idea made sense and I wanted to have a discussion about it. I thought the functional dependency idea was quite interesting, and I'm curious to understand how it relates to the concept of a derived relvar. Unfortunately you don't seem interested in engaging in a conversation. Please, I would rather if you did. Received on Fri May 29 2009 - 20:52:08 CEST

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