Re: SKOS concept scheme URIs as values for constraints

On 13/08/2015 06:44, Holger Knublauch wrote:
> On 8/12/2015 19:09, Phil Archer wrote:
>> Actually, in this case, the test could be:
>> 1. the value of a dcterms:subject property matched
>> /http:\/\/id\.loc\.gov\/authorities\/subjects\/\d+$/
>> AND
>> 2. an HTTP HEAD request returns a 200 response
> Could this be extended so that the HTTP look-up only needs to happen if
> there is no local copy of that namespace, e.g. as a named graph?

I'd say that was a user choice. In some cases, a local copy would be 
preferable for the reasons you say, in others - "have you used the 
current concepts defined by authority X?" - can only be tested with a 
live look up. The user would then make the choice between the slow live 
look up and the quick local check.

  I can
> imagine that many enterprise setups would not want to rely on live data
> from the public internet to look up reference data.  If only for
> performance reasons, it should probably be an option to use local copies
> that are updated in regular intervals. Then, if no such named graph
> exists, do the HTTP request as a last measure?

The live version isn't a fall back: it's the ground truth. So I'm hoping 
for a  check that the data I have is referring to the external resources 
as defined by an external authority. A stage that checked that a locally 
held copy was still up to date could precede the regular validation - 
HTTP caching would no doubt be useful there. This seems in line with 
what Miika is suggesting?


> Holger


Phil Archer
W3C Data Activity Lead
+44 (0)7887 767755

Received on Thursday, 13 August 2015 10:39:07 UTC