CORNER: A Completeness Reasoner for SPARQL Queries Over RDF Data Sources

  • Fariz Darari
  • Radityo Eko Prasojo
  • Werner Nutt
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8798)


With the increased availability of data on the Semantic Web, the question whether data sources offer data of appropriate quality for a given purpose becomes an issue. With CORNER, we specifically address the data quality aspect of completeness. CORNER supports SPARQL BGP queries and can take RDFS ontologies into account in its analysis. If a query can only be answered completely by a combination of sources, CORNER rewrites the original query into one with SPARQL SERVICE calls, which assigns each query part to a suitable source, and executes it over those sources. CORNER builds upon previous work by Darari et al. [1] and is implemented using standard Semantic Web frameworks.


Data quality Data completeness Query completeness SPARQL 



This work has been partially supported by the project “MAGIC: Managing Completeness of Data” funded by the province of Bozen-Bolzano, and the European Master’s Program in Computational Logic (EMCL).


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    Harris, S., Seaborne, A.: SPARQL 1.1 query language. Technical report, W3C (2013)Google Scholar

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Fariz Darari
    • 1
  • Radityo Eko Prasojo
    • 1
  • Werner Nutt
    • 1
  1. 1.Faculty of Computer ScienceFree University of Bozen-BolzanoBolzanoItaly

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