Re: R2RML - SQL string representations

On 21 Nov 2011, at 17:24, David McNeil wrote:
> The R2RML spec [1] has language in section 10.3, that prescribes the mapping of SQL string values to plain literals. This surprises me, I would expect SQL strings to map to XSD strings. My understanding is that the RDF group is moving away from plain literals. What do you think of changing this to map SQL strings to XSD strings?

The current behaviour should remain IMO. In the wild, plain literals are more common than xsd:string typed literals by an order of magnitude or so (I have the numbers somewhere). We should optimize for the common case. And it's already easy to generate xsd:strings simply by specifying the rr:datatype.

In RDF 1.1, there is no difference between plain literals and xsd:string typed literals. They are the same thing. So it's not a move away from plain literals, it's just abolishing a distinction. If R2RML were to target RDF 1.1, then it wouldn't matter if we said “generate a plain literal” or “generate an xsd:string typed literal” – it would result in the same graph. But as long as we target the old RDF, the distinction matters.

Best,
Richard

Received on Monday, 21 November 2011 18:03:33 UTC