Service Structure

• Persistent Identifier (PID) - This describes the location of an object’s persistent data in some Datastore and generates a string identifier for that data.

• Persistent Object (PO) - This is an object whose persistence is controlled externally by its clients.

• Persistent Object Manager (POM) - This component provides a uniform interface for the implementation of an object’s persistence operations. An object has a single POM to which it routes its high-level persistence operations to achieve plug and play.

• Persistent Data Service (PDS) - This component provides a uniform interface for any combination of Datastore and Protocol, and coordinates the basic persistence operations for a single object.

• Protocol - This component provides one of several ways to get data in and out of an object.

• Datastore - This component provides one of several ways to store an object’s data independently of the address space containing the object.