On the handling of imperfect data in relational database systems - from null values to possibility distributions

摘要

In this papre, we present a brief survery of some approaches that have been proposed for the treatment of imperfect data in relational database systems and we focus on the possibility theory-based approach which is shown to provide a unifying way of bandling uncertain and imprecise data. We are then concerned with the Boolean querying of possibilistic databases. We point out some interesting properties as well as some current research issues relating to the use of the possibilistic approach in a relational database context.