k-Nearest Keyword Search in RDF Graphs

Resource Description Framework (RDF) has been widely used as a W3C standard to describe the resource information in the Semantic Web. A standard SPARQL query over RDF data requires query issuers to fully understand the domain knowledge of the data. Because of this fact, SPARQL queries over RDF data are not flexible and it is difficult for non-experts to create queries without knowing the underlying data domain. Inspired by this problem, in this paper, we propose and tackle a novel and important query type, namely k-nearest keyword (k-NK) query, over a large RDF graph. Specifically, a k-NK query obtains k closest pairs o