The Role of Polymorphic Reuse Mechanisms in Schema Evolution in an Object-Oriented Database

A seamless approach to the incremental design and reuse of object-oriented methods and query specifications is presented. We argue for avoiding or minimizing the effort required for manually reprogramming methods and queries due to schema modifications, and demonstrate how the role of polymorphic reuse mechanisms is exploited for enhancing the adaptiveness of database programs against schema evolution in an object-oriented database. The salient features of our approach are the use of propagation patterns and a mechanism for propagation pattern refinement. Propagation patterns are employed as an interesting specification formalism for modeling operational requirements. They encourage the reuse of operational specifications against the structural modification of an object-oriented schema. Propagation pattern refinement is suited for the specification of reusable operational modules. It promotes the reusability of propagation patterns towards the operational requirement changes. This app..