--It is fault-tolerant--crashes of clients or servers during garbage collection will not corrupt the state of the persistent object
Initially, such movement will be under programmer control, but we will need to devise ways in which the placement of objects can be controlled automatically by the system itself, in much the same way that persistent objects
migrate from disk to main memory and back again without direct programmer intervention.
In Proceedings of the 6th International Workshop on Persistent Object
Systems (Tarascon, France, Sept.) Springer-Verlag, New York, 331-354.
Here we explore the potential of metasystems and the technical problems that have to be solved to realize them, highlighting five metasystem uses: shared persistent object
spaces; transparent remote execution; wide-area queueing systems; wide-area parallel processing; and meta-applications.
The POA supports two types of CORBA objects: the persistent object
originally specified by CORBA, and a new shorter-lived object called a transient object.
A persistent object
has a life cycle quite independent of that of its servant.
This standard, called the persistent Object
Adapter (POA), provides ORB portability.
Object Request Brokers (ORBs) then mediate the interactive access linking the icons in the graphical patient record to the distributed databases that provide the persistent object
storage for the multimedia data.
A create operation can be used to make an object (given by a reference) into a persistent root, that is, a persistent object
with a specified name to be used when retrieving it from the OODB server with a get operation.
These facilities sped debugging and simplified the code of many parts of the operating system, for example, the file system, application interface, name servers, and persistent object
Stores: Object managers such as Mneme  and ObServer [17[ have been built without all the functionality of the DBMSs described here.
Also, when an object o is no longer referenced by any other persistent object
or value, the space it occupies in memory and on disk is recovered if the object is not attainable by any temporary variable or any temporary object.