A framework for global constraint checking involving aggregates in multidatabases using granular computing

Abstract

We have earlier introduced constraint checker, a general framework for checking global constraints using an agent based approach. In this paper, we complement the constraint checker with algorithms for checking global constraints involving aggregates in the presence of updates. The algorithms take as input an update statement, a list of global constraints involving aggregates, and granulizes each global constraint into sub constraint granules. The sub constraint granules are executed locally on remote sites and then the algorithm decides if a constraint is violated based on these sub constraint executions. The algorithms are efficient as the global constraint checks are