This volume consists of a collection of 28 papers presented at the NATO Advanced Study Institute held July 14-27, 1985 in the beautiful resort at Les Arcs, France. The director of this ASI was A. K. Sood and A. H. Qureshi was the co-director. Since its introduction in the early 1970s the relational data model has been widely accepted. Several research and industrial efforts are being undertaken to develop special purpose database machines to implement the relational model. In addition, database machines are being explored for applications such as image processing and information retrieval. In...