Semantic Rules to Propagate Versions in Object-Oriented Databases

Object versions are a key feature of object-oriented database evolution. The applications targeted by OODBs (such as CAD or CASE applications) need to manipulate complex objects, i.e objects linked to other objects by dependence relations (composition, inheritance, association, etc.) and, consequently, complex object versions. This paper investigates the existing approaches in complex object version management through version propagation, i.e the automatic creation or destruction of groups of linked object versions. The main issues of version propagation are underlined : limitation of the scope, version referencing and ambiguous propagation cases management. The paper then presents the authors’ approach: a user-customizablemulti-strategy version propagationmodel in which the propagation capabilities, called strategies, can be declaratively described by means of rules and associated with each relation, according to its semantics. A comprehensive example of composite class and instance version propagation illustrates the capabilities of the model.