A method for rapidly identifying terms that are associated with a given root term by a transitive relationship defined by hierarchical ontology data stored in a relational database. A transitive closure table is created that comprises a plurality of rows each of which specifies a term and an associated...http://www.google.de/patents/US20060036633?utm_source=gb-gplus-sharePatent US20060036633 - System for indexing ontology-based semantic matching operators in a relational database system
