Re: Pre-CR review - Section 4 comments

On 23 Jan 2012, at 15:32, David McNeil wrote:
> * My last call comment on this still stands: Doesn't this definition of a mandatory error contradict our stated intent of: if data values fall outside of the intersection of SQL data types and XSD data types then the behavior is undefined (but throwing an error is not required)?

Are you referring to this?

[[
The following conditions give rise to data errors: […] A term map that has a validatable RDF datatype as its specified datatype produces an ill-typed literal.
]]

An ill-typed XSD literal is a violation of the XSD spec. Many RDF parsers blow up when reading RDF that contains ill-typed literals (notably Sesame).

> I don't remember seeing a place in the spec that captures our intent regarding the intersection of SQL and XSD data types.

That intent was about which SQL types to handle in the natural mapping from SQL values to RDF literals. This is captured in Section 10.2 – it only handles the intersection of Core SQL 2008 and XSD.

The natural mapping never produces data errors. The condition quoted above can never arise from the natural mapping. It can arise only when the natural datatype is overridden using rr:datatype, and captures some of the many ways how users can shoot themselves in the foot using that feature.

Best,
Richard

Received on Monday, 23 January 2012 16:48:16 UTC