Re: Database design

Mark Johnson <102334.12_at_compuserve.com> wrote:

>mAsterdam <mAsterdam_at_vrijdag.org> wrote:
>
>>What is your definition of the relevant terms?
>
>I like that question.
>
>A relation is a set of unsorted, unordered unique tuples, which may
>only contain data - not text. I'm not sure about the last bit.
>
>But which leads back to the question. If a sort column/attribute is
>included, is it definitionally destroyed by saying it doesn't sort, or
>that whatever is sorted is not a, relation? Is it just semantics, as
>the term is commonly used? If you have horses at the gate, in other
>words, and their performance is tied, among other factors, to their
>start position, then is that not an ordered relation?

In fact, let me amend that, before someone says it's merely a scalar weight, and not an order. A horse runs in two races, separated by two more. Its performance in the second can depend on that separation and its performance in the first, never mind how it runs in that race by itself. So in a relation of races, is not the number of the race more than merely an identifier. At what point does an attribute sort a relation? Received on Wed Feb 22 2006 - 03:28:43 CET