Evolution of Persistent Types

Persistent type evolution is a problem specific to the modification of types used to define persistent objects. In languages that support object persistence directly, such as Java, the storage representation used for persistent objects is derived directly from the object's type representation. If a programmer modifies the structure of a persistent type, that modification affects both its representation in virtual memory and its representation in a persistent object base. If an object is written to an object base, and then the type representation used by that object is changed, it may no longer be possible to read the object from the persistent object base. My research addresses four broad problems of persistent type evolution: The following papers are available:
Barbara Staudt Lerner, "TESS: Automated Support for the Evolution of Persistent Types", in Proceedings of the 1997 Automated Software Engineering Conference (ASE'97), November 1997.

Barbara Staudt Lerner, A Model for Compound Type Changes Encountered in Schema Evolution, Technical Report 96-044, Computer Science Department, University of Massachusetts at Amherst, June 1996.
To ftp the report, click UM-CS-1996-044

Barbara Staudt Lerner, Type Evolution Support for Complex Type Changes, Technical Report 94-071, Computer Science Department, University of Massachusetts at Amherst, 1994.
To ftp the report, click UM-CS-1994-071
This work was supported in part by the Air Force Materiel Command, Rome Laboratory, and the Defense Advanced Research Projects Agency and in part by the National Science Foundation.