Wouldn't the union graph provide different answers in some cases?

for example

g2 contains

 ?sub rdfs:subClassOf  ex:foo

and g3 contains

ex:foo rdfs:subClassOf <http://xmlns.com/foaf/0.1/Person> .

the original query would not resolve

?sub *rdfs:subClassOf** <http://xmlns.com/foaf/0.1/Person> .

would it?

but the union graph would.

At least I think that is the case.


On Thu, Feb 8, 2018 at 8:39 AM, Jean-Marc Vanel <jeanmarc.va...@gmail.com>
wrote:

> Hi
>
> I wonder about performance of  arbitrary length path in Jena :
> https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#
> propertypath-arbitrary-length
>
> For example , here is the query in semantic_forms for searching a string
> with a type class. I added yesterday the rdfs:subClassOf* pattern.
> I wonder if it would not be more efficient with the unionGraph instead of
> numerous GRAPH blocks .
>
> PREFIX text: <http://jena.apache.org/text#>
> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
> PREFIX form: <
> http://raw.githubusercontent.com/jmvanel/semantic_forms/
> master/vocabulary/forms.owl.ttl#
> >
>
> SELECT DISTINCT ?thing ?COUNT WHERE {
>  ?thing text:query ( 'Jean*' ) .
>
>  graph ?g1 {
>    ?thing a ?sub .
>  }
>  graph ?g2 {
>    ?sub *rdfs:subClassOf** <http://xmlns.com/foaf/0.1/Person> .
>  } .
>  OPTIONAL {
>    graph ?grCount {
>     ?thing form:linksCount ?COUNT.
>   } }
> }
> ORDER BY DESC(?COUNT)
> LIMIT 10
>
>
> --
> Jean-Marc Vanel
> http://www.semantic-forms.cc:9111/display?displayuri=http:/
> /jmvanel.free.fr/jmv.rdf%23me#subject
> <http://www.semantic-forms.cc:9111/display?displayuri=http:/
> /jmvanel.free.fr/jmv.rdf%23me>
> D├ęductions SARL - Consulting, services, training,
> Rule-based programming, Semantic Web
> +33 (0)6 89 16 29 52
> Twitter: @jmvanel , @jmvanel_fr ; chat: irc://irc.freenode.net#eulergui
>



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