Schema Evolution publication categorizer

Object-oriented databases enforce behavioral
schema consistency rules to guarantee type
safety, i.e., that no run-time type error can
occur. When the schema must evolve, some
schema updates may violate these rules. In
order to maintain complete behavioral schema
consistency, traditional solutions require significant
changes to the types, the type hierarchy
and the code of existing methods. Such
operations are very expensive in a database
context. To ease schema evolution, we propose
to support exceptions to the behavioral
consistency rules without sacrificing type