Hi all;
The real problem with using the trigger approach is as follows:
Normally the unique constraint is handled by an index (most efficient way),
but doing so using a trigger is more likely to lose this benefit and give
you some performance problems.
IIRC, the problems with inherited keys are, at present, the fact that
inherited indexes pose some problems. Again, custom triggers would solve
that problem perhaps at a performance cost.
Best Wishes,
Chris Travers