Towards Efficient Query Processing over Heterogeneous RDF Interface

Gabriela Montoya, Christian Aebeloe, Katja Hose

Abstract: Since the proposal of RDF as a standard for representing statements about entities, diverse interfaces to publish and strategies to query RDF data have been proposed. Although some recent proposals are aware of the advantages and disadvantages of state-of-the-art approaches, no work has yet tried to integrate them into a hybrid system that exploits their, in many cases, complementary strengths to process queries more efficiently than each of these approaches could do individually. In this paper, we present an approach that exploits the diverse characteristics of queryable RDF interfaces to efficiently process SPARQL queries; we present a brief study of the characteristics of some of the most popular RDF interfaces (brTPF and SPARQL endpoints); a method to estimate the impact of using a particular interface on query evaluation, and a method to use multiple interfaces to efficiently process a query. Our experiments using a well-known benchmark dataset and a large number of queries, with answer sizes varying from 1 up to 1 million, show execution time gains of up to three orders of magnitude and data transfer reduction of up to four orders of magnitude.

Keywords: query processing, RDF interfaces, brTPF, SPARQL endpoint

Submission Category: Research Article