ABSTRACT
Digital Enterprise Research Institute, National University of Ireland, Galway
Marcel Karnstedt
Digital Enterprise Research Institute, National University of Ireland, Galway
Axel Polleres
Siemens AG Österreich, Austria
Kai-Uwe Sattler
Ilmenau University of Technology, Germany
The recent developments around Linked Data have led to the exposure of large amounts of data on the Semantic Web amenable to automated processing in software programs [99]. Linked Data sources use RDF (the Resource Description Framework) in various serialization syntaxes for encoding graphstructured data, and the Hypertext Transfer Protocol (HTTP) for data transfer. Currently only a few data sources on the Web provide full query processing capabilities (e.g., by implementing SPARQL [142,444], a query language and protocol for RDF); there are millions of RDF documents but only around 360 public SPARQL endpoints.