Re: A simple notation, again

David Cressey wrote:
...
> I'm with you on this right up to the point where you say you think that this
> is a fairly minor point of Codd's.
>
> List processing systems were quite well developed in 1970, both in terms of
> processing, and in terms of storage and retrieval. The Pick system that
> sometimes gets touted in here is basically a list processing system. List
> processing systems are fundamentally different from systems based on the
> relational model precisely because the list (1, 2) is not recognized as
> equal to the list (2, 1). Whether this is a convenience to the
> user-programmers, or represents an additional burden on them, in terms of
> the semantics of the data, is a very major point, indeed.
>
> The above says, somewhat more formally, what I was driving at a few years
> back, when I asked whether a pizza with onions and pepperoni was or was not
> the same thing as a pizza with pepperoni and onions. Unfortunately most of
> the discussion ignored the point behind the question.

I should've tried to distinguish between manipulation and presentation.   I would certainly call it a "burden" if ordering were inflicted on me when I had no app requirement for it.

I live in the pizza boondocks so I've no doubt that here there is definitely a requirement here for knowing whether onions or pepperoni go on first, but not from me. But it hardly makes a difference with all the dough they use here and it is virtually impossible to get any fresh thin-crust pizza. But this is one of those provincial places where if mustard is to be had at all, they're likely to put it on top of the relish whereas everybody knows it must go next to the meat, if there is any of that in the hotdog. I wish you'd change your example to mustard and relish as talk of pizza makes me too angry to think!

p Received on Fri Jul 20 2007 - 00:53:21 CEST