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Posted to dev@stanbol.apache.org by Alessandro Adamou <al...@studio.unibo.it> on 2014/06/10 17:01:13 UTC
Named graph support in Referenced Sites
Hi,
I've been looking into configuring a Referenced Site (fully live,
non-cached and entirely SPARQL-queried) into a running EntityHub.
Problem is, the target RDF store is fully quad-based, all the data are
in named graphs and the configuration of the default graph is not to
compute the union. And since the default graph is queried, only
quad-pattern queries are satisfied.
According to the RDF store log, the entity Hub queries are of the form,
e.g. for a 'find':
CONSTRUCT {
?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1 .
<http://stanbol.apache.org/ontology/entityhub/query#QueryResultSet>
<http://stanbol.apache.org/ontology/entityhub/query#queryResult> ?id .
} WHERE {
{ ?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1
FILTER(regex(str(?v_1),"Paderb.*","i")) .
} }
A query like this will never have any results in the RDF store I'm
using. I'm wondering if there is any way to configure queries and/or
Sites so that they can:
* supply named graphs as FROM [NAMED] clauses in the queries, and/or
* issue quad patterns a la "GRAPH ?g { }" in queries (and include them
for every triple in the result set from the entity hub)
If these are not supported, it might be worth opening a ticket for them?
Cheers
Alessandro
Re: Named graph support in Referenced Sites
Posted by Rupert Westenthaler <ru...@gmail.com>.
Hi Alessandro
Quads are not supported.
>> If these are not supported, it might be worth opening a ticket for them?
Yep. Even better if you could provide examples on how to fix the
generated SPARQL queries. The SPARQL queries are generated by [1]. For
adding this feature one would need to
1. extends [1] to support named graphs
2. add a new property to Referenced Sites that allows to configure
named graphs URIs
best
Rupert
[1] http://svn.apache.org/repos/asf/stanbol/trunk/entityhub/query/sparql/src/main/java/org/apache/stanbol/entityhub/query/sparql/SparqlQueryUtils.java
On Tue, Jun 10, 2014 at 5:03 PM, Alessandro Adamou
<al...@studio.unibo.it> wrote:
> Sorry, I meant that my default graph is always *empty*
>
> Alesandro
>
>
>
> On 10/06/2014 16:01, Alessandro Adamou wrote:
>>
>> Hi,
>>
>> I've been looking into configuring a Referenced Site (fully live,
>> non-cached and entirely SPARQL-queried) into a running EntityHub.
>>
>> Problem is, the target RDF store is fully quad-based, all the data are in
>> named graphs and the configuration of the default graph is not to compute
>> the union. And since the default graph is queried, only quad-pattern queries
>> are satisfied.
>>
>> According to the RDF store log, the entity Hub queries are of the form,
>> e.g. for a 'find':
>>
>> CONSTRUCT {
>> ?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1 .
>> <http://stanbol.apache.org/ontology/entityhub/query#QueryResultSet>
>> <http://stanbol.apache.org/ontology/entityhub/query#queryResult> ?id .
>> } WHERE {
>> { ?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1
>> FILTER(regex(str(?v_1),"Paderb.*","i")) .
>> } }
>>
>> A query like this will never have any results in the RDF store I'm using.
>> I'm wondering if there is any way to configure queries and/or Sites so that
>> they can:
>> * supply named graphs as FROM [NAMED] clauses in the queries, and/or
>> * issue quad patterns a la "GRAPH ?g { }" in queries (and include them for
>> every triple in the result set from the entity hub)
>>
>> If these are not supported, it might be worth opening a ticket for them?
>>
>> Cheers
>>
>> Alessandro
>> .
>>
>
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| A-5500 Bischofshofen
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Re: Named graph support in Referenced Sites
Posted by Alessandro Adamou <al...@studio.unibo.it>.
Sorry, I meant that my default graph is always *empty*
Alesandro
On 10/06/2014 16:01, Alessandro Adamou wrote:
> Hi,
>
> I've been looking into configuring a Referenced Site (fully live,
> non-cached and entirely SPARQL-queried) into a running EntityHub.
>
> Problem is, the target RDF store is fully quad-based, all the data are
> in named graphs and the configuration of the default graph is not to
> compute the union. And since the default graph is queried, only
> quad-pattern queries are satisfied.
>
> According to the RDF store log, the entity Hub queries are of the
> form, e.g. for a 'find':
>
> CONSTRUCT {
> ?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1 .
> <http://stanbol.apache.org/ontology/entityhub/query#QueryResultSet>
> <http://stanbol.apache.org/ontology/entityhub/query#queryResult> ?id .
> } WHERE {
> { ?id <http://www.w3.org/2000/01/rdf-schema#label> ?v_1
> FILTER(regex(str(?v_1),"Paderb.*","i")) .
> } }
>
> A query like this will never have any results in the RDF store I'm
> using. I'm wondering if there is any way to configure queries and/or
> Sites so that they can:
> * supply named graphs as FROM [NAMED] clauses in the queries, and/or
> * issue quad patterns a la "GRAPH ?g { }" in queries (and include them
> for every triple in the result set from the entity hub)
>
> If these are not supported, it might be worth opening a ticket for them?
>
> Cheers
>
> Alessandro
> .
>