...interesting question about constraint vs index that I wont
try to answer cos I really dont know, but suspect it is probably
"6 of one or half a dozen of the other" in this situation. :-)

> Also - I plan to try a security database replication methodology
> and I intend to add a PK type integer to the USERS table for the
> purpose. (plus a trigger and generator of course, for it).
> Can anyone tell me if this is going to cause a problem?

From the release notes for the FB v2 alphas...
"The server now rejects any access to security2.fdb except
through the Services Manager."

This seems likely to cause difficulties for such things as
replication - unless you can work out ways to do it all
through the services manager.

--
Geoff Worboys
Telesis Computing