Recent studies reveal that publicly available SPARQL endpoints exhibit significant limitations in supporting real-world applications. In order for this querying infrastructure to reach its full potential, more flexible client-server architectures capable of deciding appropriate shipping plans are needed. Shipping plans indicate how the execution of query operators is distributed between the client and the server. We propose SHEPHERD, a SPARQL client-server query processor tailored to reduce SPARQL endpoint workload and generate shipping plans where costly operators are placed at the client site. We evaluated SHEPHERD on a variety of public SPARQL endpoints and SPARQL queries. Experimental results suggest that SHEPHERD can enhance endpoint performance while shifting workload from the endpoint to the client.
['Maribel Acosta', 'Maria-Esther Vidal', 'Fabian Flöck', 'Simón Castillo', 'Carlos Buil-Aranda', 'Andreas Harth']
SHEPHERD: a shipping-based query processor to enhance SPARQL endpoint performance