Low-Cost Queryable Linked Data through Triple Pattern Fragments

For publishers of Linked Open Data, providing queryable access to their dataset is costly. Those that offer a public sparql endpoint often have to sacrifice high availability; others merely provide non-queryable means of access such as data dumps. We have developed a client-side query execution approach for which servers only need to provide a lightweight triple-pattern-based interface, enabling queryable access at low cost. This paper describes the implementation of a client that can evaluate sparql queries over such triple pattern fragments of a Linked Data dataset. Graph patterns of sparql queries can be solved efficiently by using metadata in server responses. The demonstration consists of sparql client for triple pattern fragments that can run as a standalone application, browser application, or library.