This paper presents an abstract data model for visualizing RDF data based on the notion of nested graphs. Our study gives theoretical results that shows directions to enhance the r...
Abstract. The chase procedure, an algorithm proposed 25+ years ago to fix constraint violations in database instances, has been successfully applied in a variety of contexts, such ...
We investigate the space requirements for summaries needed for maintaining exact answers to aggregate queries over histories of relational databases. We show that, in general, a su...
Abstract. This paper introduces a formalization of a set of spatial semantic integrity constraints on an extended-relational database model. The formalization extends traditional n...