Finitely Representable Nested Relations

Advanced temporal and spatial applications require both the representation of complex objects and the ability to nitely represent innnite relations. Representing such data requires combining the constraint relational model (allowing nite representation of innnite information) and either the nested relational or the object-oriented model (allowing representation of complex objects). In this paper, we extend the nested relational calculus to deal with nitely representable relations. The aim of the language we propose, called frN RC, is to provide the right formal foundations to analyze nested constraint query languages, overcoming most limitations of already existing languages. As an example of the theoretical foundations of frN RC, we show that it is eeectively computable and has NC data complexity. Moreover, frN RC queries are independent of the depth of set nesting in data generated by intermediate computations.