This report is part of SWAD-Europe Work package 10: Tools for Scalability and Storage and addresses the scope, features and purpose of developer tools for providing semantic web data storage using existing systems that are licensed as Free Software or Open Source.
Mentions: 4Suite, EOR, Haystack, Inkling, Jena, KAON, Parka DB, rdfDB, Python RDFLib, RDFStore, RDFSuite, Redfoot, Redland, Sesame and Edutella.
Mentions large datasets available and Network APIs.
"How many triples can these systems store?
(Is this even a sensible question to ask?) Yes, although the stores may not necessarily express the data in triples. There have been reports in Survey of RDF/Triple Data Stores[TRIPSURVEY] of several million 1.5M (RDFStore), 6M (RDF Suite), 20M (rdfDB), 1.5M (Redland), 300K+ (Sesame), 800K+ (Jena)."
20 million is not that impressive. Storage of billions of triples is more reasonable. There's also the fact that it is a simpler structure so storing things like data types definately requires more space (depending on whether you use statements of course).