The PersistentBase class provides the basic functionality required by persistent objects. It automatically supports the optimistic concurrency feature. If this feature is not required, you can use the XPLiteObject class instead.
When creating a persistent object by deriving from the PersistentBase, XPBaseObject, XPCustomObject or XPObject class, an OptimisticLockingAttribute is automatically applied to it. This attribute specifies whether a session can lock a persistent object's state (allows optimistic locking to be enabled).