The Relationlog system prototype

The Relationlog system is a novel persistent deductive database system for advanced data and knowledgebased applications. It directly supports the storage and inference of data with complex structures, especially data supported in nested relational and complex-object models. The Relationlog system supports the Relationlog query language, which is a typed extension of Datalog with tuples and sets and stands in the same relationship to the nested relational and complex-object models as Datalog stands to the relational model. It also supports an SQL-like data definition language and a declarative data manipulation language. This article introduces the Relationlog language, discusses the system architecture, the design decisions incorporated within its implementation, and our experience in developing the system. Copyright  2001 John Wiley & Sons, Ltd.