Automatic Integrity Constraint Evolution due to Model Subtract Operations

When evolving Conceptual Schemas (CS) one of the most common operations is the removal of some model elements. This removal affects the set of integrity constraints (IC) defined over the CS. Most times they must be modified to remain consistent with the evolved CS. The aim of this paper is to define an automatic evolutionary method to delete only the minimum set of constraints (or some of their parts) needed to keep the consistency with the CS after subtract operations. We consider that a set of constraints is consistent with an evolved CS when: 1) none of them refer to an element removed from the original CS and 2) the set of constraints is equal or less restrictive than the original one. In this paper we present our method assuming CS defined in UML with ICs specified in OCL, but it can be applied to other languages with similar results.