Re: on determinism in SPARQL constraints

That's probably a separate issue as the different results would (probably) be
produced by two different validations of a data graph.  In the case I mention
below, the question is how often RAND is called during a single validation of
a data graph.

peter


On 10/01/2016 01:36 PM, Dimitris Kontokostas wrote:
> Thanks Peter, 
> 
> This is a good point but a possible constraint would be "an issue should not
> be issued with a future date"
> 
> given the following data graph:
>  ex:issue1 ex:issued "10-10-2016"^^xsd:date
> 
> if we run the validation now we would get different results compared to
> running a validation with the exact same input after 10 days.
> 
> How could we define a validation scenario to be deterministic but at the same
> time allowing such cases?
> Requiring identical shapes and data graph would obviously not be enough and we
> need to somehow introduce time, but not sure how.
> 
> Best,
> Dimitris
> 
> On Sat, Oct 1, 2016 at 3:25 AM, Peter F. Patel-Schneider
> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
> 
>     What happens if a SPARQL query in SHACL is non-deterministic?  Is there any
>     guarantee about when and how often SPARQL queries are processed to produce a
>     query result?
> 
>     For example are there any guarantees that
> 
>     **prefixes, etc., as needed**
> 
>     s:s1 rdf:type sh:Shape ;
>      sh:targetClass ex:c1 ;
>      sh:property [ sh:predicate ex:p1 ;
>                    sh:qualifiedMinCount 1 ; sh:qualifiedMaxCount 1 ;
>                    sh:qualifiedValueShape [
>                      sh:property [ sh:predicate ex:p2 ;
>                                    sh:shape s:s2 ] ] ] .
> 
>     s:s2 rdf:type sh:Shape ;
>      sh:sparql [ sh:prefixes ex: ;
>       sh:select """SELECT $this WHERE {
>                  BIND ( ( RAND() * 25 )  AS ?r )
>                  FILTER ( STRLEN($this) < ?r ) }""" ] .
> 
>     will never produce a violation on the data graph
> 
>     PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#
>     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>>
>     PREFIX ex: <http://ex.org/>
> 
>     ex:i1 rdf:type ex:c1 ;
>      ex:p1 [ ex:p2 ex:i3 ], [ ex:p2 ex:i3 ] .
> 
> 
>     Peter F. Patel-Schneider
>     Nuance Communications
> 
> 
> 
> 
> -- 
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia Association
> Projects: http://dbpedia.org, http://rdfunit.aksw.org, http://aligned-project.eu
> Homepage: http://aksw.org/DimitrisKontokostas
> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>

Received on Saturday, 1 October 2016 20:48:52 UTC