Stratification Criteria and Rewriting Techniques for Checking Chase Termination
The Chase is a fix point algorithm enforcing satisfaction of data dependencies in databases. Its execution involves the insertion of tuples with possible null values and the changing of null values which can be made equal to constants or other null values. Since the chase fix point evaluation could be non-terminating, in recent years the problem knows as chase termination has been investigated. It consists in the detection of sufficient conditions, derived from the structural analysis of dependencies, guaranteeing that the chase fix point terminates independently from the database instance. Several criteria introducing sufficient conditions for chase termination have been recently proposed.