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More tweaks to the R2RML document

From: Richard Cyganiak <richard@cyganiak.de>
Date: Tue, 26 Oct 2010 22:50:42 +0100
Message-Id: <E93D9CE0-4F36-4888-8898-43597B01AAA8@cyganiak.de>
To: rdb2RDF WG <public-rdb2rdf-wg@w3.org>
I made some more changes to the text, trying to resolve the remaining  
scattered “@@”s.

Most significantly, I have distributed the content from Chapter 2  
(Overview) across the sub-sections of Chapter 1, creating a new  
subsection “Mapping Overview” in the process.

Chapter 2 had some text from Souri that tried to answer Pat's  
complaint that it doesn't say anywhere what the mapping is. I tried to  
expand on that.

The significant bits of new text are quoted at the end of this  
message. I hope I haven't introduced anything controversial -- if  
anyone objects to anything, then I'll revert.

Another new thing is color-coding of the various code snippets. This  
should make it easier to tell apart the R2RML vocabulary definitions  
from the mapping examples.

I made minor changes to the Abstract and Section 1, and added more  
@@Issue boxes for future discussion, based on Sören's good feedback.

The reference to the Direct Mapping draft is removed.

That's all from my side -- over to Souri for the final pre-FPWD touches!

Best,
Richard


> The R2RML language is defined with reference to an execution  
> environment that provides a SQL connection to the input database.  
> The SQL connection must be established with sufficient privileges  
> for read access to all base tables and views that are referenced in  
> the R2RML mapping. How the SQL connection is established, or how  
> users are authenticated against the database, is outside of the  
> scope of this document. R2RML processors may use other means than  
> evaluating SQL queries against the input database, as long as the  
> results are the same.


> An R2RML mapping consists of one or more structures called  
> TriplesMaps.
>
> Each TriplesMap contains a reference to a logical table in the input  
> database. A logical table can be one of the following:
>
> 	• A base table that exists in the input SQL schema.
> 	• A view that exists in the input SQL schema.
> 	• A valid SQL query against the input schema.
> Furthermore, a TriplesMap contains a rule for mapping a logical  
> table row to a set of RDF triples. The RDF triples generated from  
> one row all share the same subject, defined by a structure called an  
> RDFSubjectTermMap. The predicates and objects generated from the row  
> are defined by RDFTermMaps, one per generated triple. The  
> RDFTermMaps are rules for generating RDF nodes from the table row's  
> values.
>
> The output of an R2RML mapping is an RDF dataset. The RDF triples in  
> the dataset are the result of applying the mapping rule of each  
> TriplesMap to the rows of its logical table.
>
> By default, all RDF triples are in the unnamed default graph of the  
> RDF dataset. A TriplesMap can contain optional rules that place some  
> or all of the triples into named graphs instead.
Received on Tuesday, 26 October 2010 21:51:23 GMT

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