The need for incorporating preference querying in database technology is a very important issue in a variety of applications ranging from e-commerce to personalized search engines....
We present a data structure used to represent planar spatial databases in the topological data model. Conceptually, such databases consist of points, lines between these points, an...
The first aim of this paper is to present the logical core of XPath 2.0: a logically clean, decidable fragment, which includes most navigational features of XPath 2.0 (complex co...
Unity is an architecture for integrating relational databases that performs three processes: metadata capture, semantic integration, and query formulation and execution. The found...
We explore the implications of supporting bags (i.e. multisets) in a data model and associated query language, and present some formal results concerned with the algebraic propert...