Database integration of a wide variety of life-science data is an important issue for comprehensive data analysis. Since Semantic Web technologies, such as Resource Description Framework (RDF), are expected to provide efficient data integration technologies, many lifescience databases are published in RDF with SPARQL Protocol and RDF Query Language (SPARQL) endpoints as search application progr...

In this paper, we propose a novel framework for RDF stream processing named PRSP. Within this framework, the evaluation of C-SPARQL queries on RDF streams can be reduced to the evaluation of SPARQL queries on RDF graphs. We prove that the reduction is sound and complete. With PRSP, we implement several engines to support C-SPARQL queries by employing current SPARQL query engines such as Jena, g...

The growing use of data analytics on Linked Data requires SPARQL engines to efficiently execute Online Analytical Processing (OLAP) queries. While SPARQL 1.1 provides appropriate basic constructs, corresponding optimization of SPARQL engines is still in its infancy and further development lacks benchmarks that mimick the data distributions found in Link Data. In fact, existing work on OLAP benc...

Diamond is a Rete match based system that evaluates SPARQL queries on Linked Data. The evaluation of SPARQL query predicates is a useful intermediate milestone for a system ultimately intended to support full rule-based inference on Linked Data. A byproduct is the integrated graphical rule debugging environment is a first of its kind debug environment for SPARQL queries.

Accessing Linked Open Data sources with query languages such as SPARQL provides more flexible possibilities than access based on derefencerable URIs only. However, discovering a SPARQL endpoint on the fly, given a URI, is not trivial. This paper provides a quantitative analysis on the automatic discoverability of SPARQL endpoints using different mechanisms.

Property paths, a part of the proposed SPARQL 1.1 standard, allow for non-trivial navigation in RDF graphs. We investigate the evaluation of SPARQL queries with property paths in a relational RDF store. We propose a translation of SPARQL property paths into recursive SQL and discuss possible optimization strategies.