Martin, when I referred to pessimistic locking system, I meant something similar to what Rod Paddock described with his own lock table. I would not advocate database locking. I think the term "reservation" or apparently "semaphore" is clearer and will use it from now on.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
