Bipolar Queries and Queries with Preferences (Invited Paper)

Abstract

The concepts of bipolar queries and queries with preferences are studied. Various interpretations of the former, recently defined by Dubois and Prade, are discussed. The latter was defined by Chomicki together with a new relational algebra operator winnow. The fuzzy version of the winnow operator is proposed. It is shown how it may be used to express a selected interpretation of the bipolar queries