Relational databases proliferate both because of their efficiency and their precise definitions, allowing for tools like SQL [SQLFN] to manipulate and examine the contents predictably and efficiently. Resource Description Framework (RDF) [RDF] is a data format based on a web-scalable architecture for identification and interpretation of terms. This document defines a mapping from relational representation to an RDF representation.
Strategies for mapping relational data to RDF abound. The direct mapping defines a simple transformation, providing a basis for defining and comparing more intricate transformations. This document includes an informal and a formal description of the transformation.
The Direct Mapping is intended to provide a default behavior for R2RML: RDB to RDF Mapping Language. It can be also used to materialize RDF graphs or define virtual graphs, which can be queried by SPARQL or traversed by an RDF graph API.