Abstract
In this paper, we present an evaluation of the performance of five representative RDF triplestores, including GraphDB, Jena Fuseki, Neptune, RDFox, and Stardog, and one experimental SPARQL query engine, QLever. We compare importing time, loading time, and exporting time using a complete version of the knowledge graph Wikidata, and we also evaluate query performances using 328 queries defined by Wikidata users. To put this evaluation into context with respect to previous evaluations, we also analyze the query performances of these systems using a prominent synthetic benchmark: SP2Bench. We observed that most of the systems we considered for the evaluation were able to complete the execution of almost all the queries defined by Wikidata users before the timeout we established. We noticed, however, that the time needed by most systems to import and export Wikidata might be longer than required in some industrial and academic projects, where information is represented, enriched, and stored using different representation means.