Re: Codd provided appropriate mathematics ... (was Re: Relational and MV (response to "foundations of relational theory"))

"Marshall Spight" <mspight_at_dnai.com> wrote in message news:lcT%b.409798$I06.4477771_at_attbi_s01...
> "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message
news:c1ocbm$ldq$1_at_news.netins.net...
> > Your last statement, Eric, is really the point. I think the original
> > idea was that relational database theory was tied to mathematical
> > relations. It is now at the point where statements that are true of
> > mathematical relations such as the fact that relations are ordered,
> > are now considered "obviously" untrue in the database relational
> > model. Ah well, such is the nature of language. --dawn
>
> If I may make a correction: in mathematical relations, the attributes
> are ordered instead of named. The elements are unordered in both
> models.
>
> I consider this difference relatively minor.

Don't confuse notation with the thing the notation represents. The notation orders attributes, but attributes have no inherent order. Received on Sat Feb 28 2004 - 05:42:42 CET