2.2. RDF and SPARQL
2.2.1. RDF framework and data model
The Resource Description Framework (RDF) is a family of W3C specifications for linking and sharing data on the Web. RDF was originally designed as a metadata model for describing and linking any kind of web resources, for example web pages, images, audio and video files, and services. It includes a graph-oriented abstract data model with optional schema definitions and a high-level declarative query language called SPARQL. RDF shares many features of semi-structured data models [ABI 00] for modeling and structuring heterogeneous information in open environments such as the Web. In particular, RDF data graphs can be produced without a predefined schema and SPARQL allows querying both schema and instance information simultaneously.
Figure 2.1. RDF graph. For a color version of this figure, see www.iste.co.uk/pivert/nosql.zip
EXAMPLE 2.1.– Figure 2.1 shows an RDF graph of French kings and queens. Following the principle...
