--- In ib-support@y..., Helen Borrie <helebor@t...> wrote:
> From every other point of view, it is wrong. Your consultant is
correct
> to say that primary keys should not have any meaning related to the
data -
> the term for this characteristic is "atomic".
>
My recollection, from all the relational theory classes I've
attended, is that the term "atomic" in connection with a data field
simply means that that field can only contain a single value (of
whatever datatype) as opposed to, say, an array field. It imposes no
restrictions or requirements on the actual value of the data or it's
meaning within the context of the table, or eve the system as a whole.

On the actual question itself, I can see no reason why the value of
the primary key should not be have a meaning related to the rest of
the data provided that:

a. The value is truly unique to the rest of the record and
b. The value CANNOT change during the life of the record

Steve
-----------------------
Stephen Lee-Woolf
Network Services
Information Services Division
University of Salford
Manchester UK