RQL: a declarative query language for RDF

Real-scale Semantic Web applications, such as Knowledge Portals and E-Marketplaces, require the managementof large volumes of metadata, i.e., information describing the available Web content and services. Better knowledge about their meaning, usage, accessibility or quality will considerably facilitate an automated processing of Web resources. The Resource Description Framework (RDF) enables the creation and exchange of metadata as normal Web data. Although voluminous RDF descriptions are already appearing, su ciently expressive declarative languages for querying both RDF descriptions and schemas are still missing. In this paper, we propose a new RDF query language called RQL. It is a typed functional language (a la OQL) and relies on a formal model for directed labeled graphs permitting the interpretation of superimposed resource descriptions by means of one or more RDF schemas. RQL adapts the functionality of semistructured/XML query languages to the peculiarities of RDF but, foremo...

• Type: Conference
• Year: 2002
• Where: WWW
• Authors: Gregory Karvounarakis, Sofia Alexaki, Vassilis Christophides, Dimitris Plexousakis, Michel Scholl
• Keywords: Internet Technology, RDF Query Language, RDF Schemas, Voluminous Rdf Descriptions, WWW 2002