The purpose of semantic query optimization is to use semantic knowledge (e.g. integrity constraints) for transforming a query into a form that may be answered more efficiently than the original version. This paper proposes a general method for semantic query optimization in the framework of Object Oriented Database Systems. The method is applicable to the class of conjunctive queries and is based on two ingredients: a formalism able to express both class descriptions and integrity constraints rules as types; subsumption computation between types to evaluate the logical implications expressed by integrity constraints rules.
Semantic Query Optimization by Subsumption in OODB / Beneventano, Domenico; Bergamaschi, Sonia; C., Sartori. - STAMPA. - (1996), pp. 167-187. (Intervento presentato al convegno Flexible Query-Answering Systems tenutosi a Roskilde (Denmark) nel May 22-24, 1996).