Europeana RDF Store Report

Expressing data in RDF is one of the principles to be considered when making data available as Linked Data on the Web. This can be achieved using RDF-wrappers for existing (relational) data stores or by using RDF stores as data repositories. The latter requires special RDF storage solutions, many of which are available today. Organizations often have difficulties to decide which solution they should adopt because comprehensive comparisons of existing RDF stores are hardly available and experiences w.r.t performance and scalability are still missing. In this report, we summarize the results of qualitative and quantitative study we carried out on existing RDF stores in the context of the European Digital Library project. We give a detailed overview on existing RDF store solutions, analyze their functional and non-functional features, summarize the outcomes of other, previously carried out studies, and conduct a Linked-Data oriented performance evaluation on a subset of existing triple stores w.r.t to load and query time. The results of this study show that certain RDF stores, such as OpenLink Virtuoso or 4Store, can deal with the Europeana data volume and answer those SPARQL queries that are relevant for exposing Europeana metadata as Linked Data in an acceptable time-range.