Persistence Layer

Current implementation has the following features.

• Encapsulation of the persistence mechanism. You should only call the save, delete, restore methods of your persistent objects and the Persistence Layer will automatically perform an action with your database.
• Multiple object actions. You can retrieve and delete multiple objects at once.
• Associations support. When you save delete or update any object you can do the same action with associated objects.
• Inheritance support. Makes possible to map an inheritance tree to a database schema.
• Transactions support. You can combine several actions into one transaction and commit or rollback it as a single action.
• Multiple database support. Different objects can be mapped to different databases.
• Optimistic and pessimistic locking support