- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Tue, 12 Oct 2010 23:46:24 +0100
- To: RDB2RDF WG <public-rdb2rdf-wg@w3.org>
I re-wrote the introduction of the R2RML draft [1], I hope it now serves as a slightly better roadmap to the purpose and concept of the document. The text is copied below for your convenience. Comments are welcome -- can it be made more clear? Should other things be mentioned early on to ease comprehension? Richard [1] http://www.w3.org/2001/sw/rdb2rdf/r2rml/Overview.html > This specification defines the syntax and semantics of R2RML, a > language for expressing customized mappings from relational > databases to RDF datasets. Such mappings provide the ability to view > existing relational data as RDF, expressed in a structure and target > vocabulary of the mapping author's choice. > > A related specification is the RDB2RDF Direct Mapping [DIRECT]. It > defines a fixed “default mapping”. In the default mapping of a > database, The structure of the resulting RDF graph directly reflects > the structure of the database, the target RDF vocabulary directly > reflects the names of database schema elements, and neither > structure nor target vocabulary can be changed. With R2RML on the > other hand, a mapping author can define highly customized views over > the relational data. > > The input to an R2RML mapping is a relational database. The output > is an RDF dataset [SPARQL], as defined in SPARQL. The mapping is > conceptual; implementations are free to materialize the output data, > or to offer virtual access through an interface that queries the > underlying database. > > R2RML mappings are themselves expressed as RDF graphs and written > down in Turtle [TURTLE] syntax. > > The intended audience of this specification are implementors of > software that generates or processes R2RML mapping documents, as > well as mapping authors looking for a reference to the R2RML > language constructs. The document uses concepts from RDF Concepts > and Abstract Syntax [RDF] and from the SQL language [SQL1][SQL2]. A > reader's familiarity with the contents of these documents, as well > as with the Turtle syntax, is assumed. > > The R2RML language is designed to meet the use cases and > requirements identified in Use Cases and Requirements for Mapping > Relational Databases to RDF [UCNR].
Received on Tuesday, 12 October 2010 22:47:02 UTC