With metaphactory, we serve customers of various sizes and across multiple industries, but no matter whether we're talking about a clinical trial scoping or a bill of materials use case, customers are looking for solutions to address hybrid information needs. That means that end users usually have questions or information needs that are not limited to one single data source or just RDF graph data, but involve simultaneously dealing with a multitude of data sources, a multitude of data modalities and a multitude of data processing techniques.
Federation is a very powerful technique for providing integrated access over multiple heterogeneous data sources. The SPARQL 1.1 query language already provides a convenient built-in way of expressing data requests over multiple RDF knowledge graphs: Via the SERVICE clause queries over multiple SPARQL endpoints can be expressed using a single query.
In metaphactory, we support SPARQL 1.1 federation and go one step further: we offer two federation techniques - Ephedra and FedX - tailored to solve specific information needs, particularly involving hybrid data sources.