The W3C RDB2RDF Working Group has published two Proposed Recommendations today:
- R2RML: RDB to RDF Mapping Language. This document describes R2RML, a language for expressing customized mappings from relational databases to RDF datasets. Such mappings provide the ability to view existing relational data in the RDF data model, expressed in a structure and target vocabulary of the mapping author’s choice. R2RML mappings are themselves RDF graphs and written down in Turtle syntax. R2RML enables different types of mapping implementations. Processors could, for example, offer a virtual SPARQL endpoint over the mapped relational data, or generate RDF dumps, or offer a Linked Data interface.
- A Direct Mapping of Relational Data to RDF. The need to share data with collaborators motivates custodians and users of relational databases (RDB) to expose relational data on the Web of Data. This document defines a direct mapping from relational data to RDF. This definition provides extension points for refinements within and outside of this document.
The group also published two Working Group Notes today:
- R2RML and Direct Mapping Test Cases. This document defines the R2RML and Direct Mapping Test Cases deliverable for the RDB2RDF Working Group.
- RDB2RDF Implementation Report. This document reports on implementations of the Direct Mapping specification and the R2RML specifications. The main purpose of this document is to show that each feature of the Direct Mapping and R2RML has been implemented by demonstrating interoperable implementations of each feature. To evaluate the coverage of an implementation’s features, the RDB2RDF Test Cases are used as a point of reference.