Computing repairs for constraint violations in UML/OCL conceptual schemas

Abstract

Updating the contents of an information base may violate some of the constraints defined over the schema. The classical way to deal with this problem has been to reject the requested update when its application would lead to some constraint violation. We follow here an alternative approach aimed at automatically computing the repairs of an update, i.e., the minimum additional changes that, when applied together with the requested update, bring the information base to a new state where all constraints are satisfied. Our approach is independent of the language used to define the schema and the constraints, since it is based on a logic formalization of both, although we apply it to UML and OCL because they are widely used in the conceptual modeling community.Our method can be used for maintaining the consistency of an information base after the application of some update, and also for dealing with the problem of fixing up non-executable operations. The fragment of OCL that we use to define the constraints has the same expressiveness as relational algebra and we also identify a subset of it which provides some nice properties in the repair-computation process. Experiments are conducted to analyze the efficiency of our approach.

Automatic Business Process Model Extension to Repair Constraint Violations

“…Translating integrity constraints into RGDs. Repair-generating dependencies (RGDs) are logic formulas that, given a database state and a data update, derive new updates that must be applied to repair a constraint violation [22]. In this step, we translate the constraints into the corresponding RGDs.…”

“…RGDs are logic formulas that, given a database state and a set of updates, derive new updates in order to repair a constraint violation [22]. Every UML/OCL constraint gives raise to several RGDs, each one capturing a dierent way to violate/repair it.…”

“…The problem of obtaining RGDs from UML/OCL constraints, and simplifying them, is already solved in [22]. For our purposes, we consider only constraints written in the UML/OCLuniv subset [20].…”

“…The obtained BPMN diagram represents all possible ways to repair the various constraints that can eventually be violated by the activity execution. This is due to the fact that RGDs capture all possible ways to repair a constraint [22], and all the RGDs are represented in the BPMN diagram. However, it might be the case that some of the proposed repairs are not desirable in the domain of the problem.…”

Adapting Integrity Checking Techniques for Concurrent Operation Executions

“…Given a constraint C, it is possible to determine, at compile time, which are the kind of structural events that might violate a constraint, and also those that may repair it [18,7]. For our purposes, we use the approach defined in [18] since it is based on logics in a similar way as we did in previous section.…”