Deductive object-oriented databases advocate the advantage of combining object-oriented and deductive paradigms into a single data model. Certainly, the query language in such a data model has to reflect the amalgamation because it works as the interface to the user and/or application program. This paper proposes a language to formulate queries as classes related to the schema classes and constrained by an associative membership condition. Answers are then regarded as their instances. The interpretation is based on a deductive database view of queries. Generic query classes are introduced with a simple parameter substitution construct. The syntactic separation of structural and associative conditions opens the way to semantic query optimization: subsumption between the structural parts of queries can be decided efficiently.
原文链接
分享
引用
