You're not going to be able to have Snow proactively lock that down for you because Snow is designed to read and report on only. If the Oracle application itself or the administration screen of the application doesn't have the necessary intelligence you may be able to set up an alert to monitor the rolling maximum and trigger when it's breached. I've not worked with Snow's Oracle module much to know if an alert of this kind is possible.

-application itself [an activation key with the max encrypted into it and the software is designed to read and take action on that value]

-administration screen [has a field where you enter that maximum qty and the software is designed to read and take action on that value. You'll need to make sure the value entered is correct. I've seen all 9s entered just so the admin could get their install completed.]