Consistent Handling of Integrity Constraints and Extensional Assertions for Schema Integration

Schema integration is a main step in the database integration process. Since the semantics of a schema is also determined by its integrity constraints, a correct and complete schema integration has to deal with integrity constraints existing in the different schemas to be integrated. In this paper, we present a framework for the correct handling of integrity constraints during schema integration. In particular, we work out the correspondence between local integrity constraints and global extensional assertions. The knowledge about the correspondences between the underlying integrity constraints and extensional assertions can then be utilized for an augmented schema integration process.