Abstract: Extensive work has recently been done on the evaluation of positive queries on probabilistic databases. The case of queries with negation has notoriously been left out, since it raises ...

There are two types of relational database manipulation language: procedural and assertional. A procedural language is one in which a query is expressed through a sequence of operations. This category ...

Abstract: We present multi-ranked relational model of data which extends the classic Codd's model by considering similarity relations on domains and ranks assigned to values of tuples. The ranks ...