Temporal and versioning model for schema evolution in object-oriented databases

摘要

In this paper we define the Temporal and Versioning Model for Schema Evolution (TVSE), a model that uses time and version concepts to manage dynamic schema evolution in object-oriented databases. The proposed model is able to manage the schema evolution process considering: schema versioning, schema modification, change propagation and data manipulation. TVSE differs from other schema evolution models by enabling the homogeneous and simultaneous management of the evolution history concerning both intentional and extensional databases. Besides defining the model, we also propose a language to derive and modify schema versions, and also to update data associated with them, creating either new object versions or just keeping the history of these data modifications. We provide an operational semantics for this language which is an essential step towards for establishing the preservation of complex time integrity constraints.