An update lock allows a JADE session to update a JADE object, while still allowing other sessions to acquire shared locks (but not any other type of lock). The other JADE sessions with shared locks see the most-recently committed edition of the object, without the pending updates.
Update locks can be used only within a transaction.
When a JADE session commits a transaction, any update locks are automatically requested to be upgraded to exclusive locks before the updates are committed. This ensures that no other JADE sessions have the objects locked at the time the updates are committed.