triplestore

IBM's DB2 as a triplestore

Surprisingly easy to set up and use, but requiring lots of Java coding for any real application development.

I thought it was pretty big news for the semantic web world when IBM announced that release 10.1 of their venerable DB2 database manager could function as an RDF triplestore, but it seems that few others—not even, apparently, IBM staff responsible for marketing semantic technology—agreed with me. More on this below.

Getting started with Open Anzo

Don't miss the exciting command line video demo!

Open Anzo is the third disk-based triplestore that I managed to set up, load with a few files of RDF data, and query with SPARQL. Its home page describes it as “an open source enterprise-featured RDF store and service oriented middleware platform that provides support for multiple users, distributed clients, offline work, real-time notification, named-graph modularization, versioning, access controls, and transactions with preconditions”.

Querying a set of named RDF graphs without naming the graphs

A big step toward using named graphs to track provenance.

I’d like to thank everyone who added comments to my last post, Some questions about RDF named graphs. Lee Feigenbaum wrote an entire blog post addressing the issues I raised, and it looks like his Open Anzo triplestore (which I’ll write up in its own post soon) has some nice support for versioning, access control, and replication.

Just about all the RDF triplestores I’ve been trying were designed from the ground up to store RDF triples. OpenLink Software’s Virtuoso is a database server that can also store (and, as part of its original specialty, serve as an efficient interface to databases of) relational data and XML, so some of my setup and usage steps required learning a few other aspects of it first. For example, the actual loading of RDF is done using Virtuoso’s WebDAV support, so I had to learn a…