A deductive data model for representing and querying semistructured data
Fosca Giannotti, Giuseppe Manco, Dino Pedreschi · 1997
We show how the mechanisms of an active/deductive object-oriented model are capable of modeling the information available on the World Wide Web, the paradigmatic example of a large, distributed collection of poorly structured, heterogeneous information, consisting of documents connected by hypertext links. We exhibit the basic features of the object model, including the schema definition language, the query language with multiple roles, the basic update operations, and a form of active rules, and a compilation of the mentioned features into a fragment of LDL++, which is essentially Datalog extended with non-determinism and a form of stratified negation. The proposed compilation has a twofold aim. On one side, it should provide an abstract implementation level, where the object model is declaratively reconstructed and its semantics clarified. On the other side, the proposed compilation should form the basis of a realistic implementation, as LDL++ can be efficiently executed, and suppor...