> You are presuming that all database apps are client-server.
> There are also distributed systems that can, by nature of their
> job, have no centralized "server" that is common, but must depend
> on intermittent merges for synchronization. Any database app
> that is used for data gathering in a mobile environment, or any
> system that must be able to function for prolonged periods in the
> absence of communications to a "central" database.
>
> [Non-text portions of this message have been removed]
>
>

Of course I am - my comments only apply to C/S and not to all of them
either.
I do not contest the use of non-integer PKs. I merely comment that there are
people thinking, here and via question to me regarding FBReplicator, that
integers are no good because of their ultimate lack of scale... After I
point out the scale of integers (especially Int64) to them and the likely
demands they will have by their application, that integers are indeed a
valid choice for PK.
Alan
PS - I have mobile applications (Palm) which function for prolonged periods
in the absence of comms with the central server. They generate -tive PKs
locally. When they do sync, they replace their negative PKs with server
supplied +ive PKS and the detail records (foreign keys) are replaced, also,
in the same operation. This method works well and relies only on integer
values. So integers can operate here equally well.