Statement Graphs: Unifying the Graph Data Model Landscape

Graph database users today face a choice between two technology stacks. The Resource Description Framework (RDF), on one side, is a data model that was originally developed by the W3C to exchange interconnected data on the Web. On the other side, Labeled Property Graphs (LPGs) are geared towards efficient graph processing and have strong roots in developer and engineering communities. The two models look at graphs from different abstraction layers, expose - at the surface - distinct features, come with different query languages, and are embedded into their own software ecosystems. Typical industry use cases call for applications which must bridge data systems under both stacks, leading to ad hoc and costly solutions. Towards remedying this pain point, we introduce a novel unifying graph data model called Statement Graphs, which combines the traits of RDF and LPG, and achieves interoperability at different levels: it (a) provides the ability to manage RDF and LPG data as a single, interconnected graph, (b) enables read querying over the integrated graph using any RDF or LPG query language, while (c) clearing the way for graph stack independent data exchange mechanisms. As a proof of concept, we present the 1G Playground; an in-memory DBMS built on the concepts of Statement Graphs, which facilitates storage of both RDF and LPG data, and allows for cross-model read querying using SPARQL and Gremlin.