Category Classes: Flexible Classification and Evolution in Object-Oriented Databases

Object-oriented databases (OODBs) are believed to more naturally reflect the behavior and organization of real world objects. However, OODBs are mostly concerned about only the static aspects of object modeling. While real world objects typically may be multiperspectived and evolve over time by changing classification and behavior, contemporary OODB models typically regard objects as instances of classes in such a way that classification (and thus behavior) is fixed at the time of creation.