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R2RML draft - new introduction

From: Richard Cyganiak <richard@cyganiak.de>
Date: Tue, 12 Oct 2010 23:46:24 +0100
Message-Id: <950DF62F-60C2-4F8C-BE5F-03DE74FFE30B@cyganiak.de>
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?


[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

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