Proposal for shared SQL-to-XSD mapping for DM + R2RML

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PROPOSAL: Address ISSUE-69 and RC's Last Call comment by changing the DM document as described below
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This proposal addresses the following open items:

ISSUE-69: datatype sizes
http://www.w3.org/2001/sw/rdb2rdf/track/issues/69

Last Call item [14]: DM and R2RML should use same datatype mapping
http://lists.w3.org/Archives/Public/public-rdb2rdf-comments/2011Oct/0019.html

Rationale: The datatype mapping section in R2RML has been re-written in order to make it easier to reference the mapping from external documents, and it has now contains additional non-normative text regarding the size of datatypes:

[[
In [SQL2], the precision of many SQL datatypes is not fixed, but left implementation-defined. Therefore, the mapping to XML Schema datatypes must rely on arbitrary-precision types such as xsd:decimal, xsd:integer and xsd:dateTime. In practice, implementers of the mapping may wish to set upper limits for the supported precision of these XSD types. The XML Schema specification allows such partial implementations of infinite datatypes [XSD2-11], and defines specific minimum requirements.
]]
http://www.w3.org/2001/sw/rdb2rdf/r2rml/#natural-value-mapping

I believe that this answers Eric's ISSUE-69 requirement that some reasonable upper limits for datatype sizes are stated.




Required changes to the DM document:

1. Remove “Definition literal map” and the following paragraph

2. Add R2RML as normative reference

3. Change “Definition literal triple”:

[[
object: the natural RDF literal [R2RML] corresponding to the column value
]]

where “natural RDF literal” is a link to:
http://www.w3.org/2001/sw/rdb2rdf/r2rml/#dfn-natural-rdf-literal

Received on Monday, 14 November 2011 12:55:59 UTC