On Feb 3, 2006, at 7:25 , Merlin Moncure wrote:
>> There is also the problem that a name can change. People change
>> names
>> by deed-poll, and also women can adopt a married name or keep
>> their old
>> one. All in all an ID is about the only answer.
>
> I'll take the other side of this issue. The fact that a primary key
> is mutable does not make it any less primary. As long as we can can
> count on it to be unique, how often identiying info changes has no
> bearing on its selection as a p-key from a relational standpoint.
> The performance issue has zero meaning in a
> conceptual sense however and I think you are trying to grapple things
> in conceptual terms.
I definitely agree with you here, Merlin. Mutability is not the issue
at hand. May I ask what strategies you use for determining uniqueness
for people?
Michael Glaesemann
grzm myrealbox com