Quadstores are a form of database used to store semantic web data.. RDF is encoded as subject--predicate--object triples and often stored in a triplestore. A quadstore allows several graphs of RDF data to be stored in teh same database. Each item in the quadstores is of the form ( graph URI, subject, predicate, object ) and it is possible to query over a particular graph, all graphs or other combinations of graphs. The graph URI can itself be used as the subject in assertions allowing provenance to be represented, for example, the origin, authority or relaibility of a particualr sub-collection (graph) of triples.
Defined on page 391
Used on page 391