Yes, the approach that Andy suggested in an email earlier today (use _one_ TDB2 
instance, load your graphs into different named graphs in it, and enable the 
"default graph = union graph" option) is the right choice.

ajs6f

> On Jan 16, 2019, at 10:50 AM, Svensson, Lars <[email protected]> wrote:
> 
> On Wednesday, January 16, 2019 4:17 PM, ajs6f [mailto:[email protected]] wrote:
> 
>> I'm not quite sure what's going on here. It looks like you are trying to 
>> load entire
>> datasets as named graphs in another dataset, but that doesn't make any sense.
>> Datasets contain graphs. You can't shove an entire dataset into a graph.
>> 
>> Are you trying to extract a particular graph from each of these datasets to 
>> insert into
>> another?
>> 
>> Perhaps you can tell us a bit more about what you are trying to accomplish 
>> here, and
>> we can help you find out how to do that.
> 
> My use case is that I have some (fairly large) RDF files (in n-triples) that 
> I want to expose through Fuseki.
> The contents of each file must be in its own named graph.
> I also want the default graph to be the union of all the named graphs.
> 
> So far I have loaded each RDF file into its own TDB2 store, but if I 
> understand you correctly that is the wrong approach...
> 
> Thanks,
> 
> Lars
> 
>>> On Jan 16, 2019, at 4:25 AM, Svensson, Lars <[email protected]> wrote:
>>> 
>>> Greetings,
>>> 
>>> I have several TDB2 datasets that I want to expose as named graphs and as a
>> joint dataset. My basic idea is to have each TDB2 dataset as its own graph 
>> and then
>> a joint dataset combining all graphs with the default graph being the union 
>> of all
>> named graphs. My configuration is:
>>> 
>>> @prefix fuseki:  <http://jena.apache.org/fuseki#> .
>>> @prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>>> @prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#> .
>>> @prefix tdb2:     <http://jena.hpl.hp.com/2016/tdb#> .
>>> @prefix ja:      <http://jena.hpl.hp.com/2005/11/Assembler#> .
>>> @prefix :        <#> .
>>> 
>>> <#service1> rdf:type fuseki:Service ;
>>>   fuseki:name                     "/dnb" ;   # http://host:port/dnb
>>>   fuseki:serviceQuery             "query" ;    # SPARQL query service
>>>   fuseki:serviceReadGraphStore    "data" ;     # SPARQL Graph store protocol
>> (read only)
>>>   fuseki:dataset           <#dnb> ;
>>>   .
>>> 
>>> <#dnb> a ja:RDFDataset ;
>>>   tdb2:unionDefaultGraph true ;
>>>   ja:namedGraph [
>>>       ja:graphName <https://d-nb.info/datasets/authorities#dataset> ;
>>>       ja:graph <#authorities>
>>>   ];
>>>   ja:namedGraph [
>>>       ja:graphName <https://d-nb.info/datasets/bib#dataset> ;
>>>       ja:graph <#bib>
>>>   ];
>>>   ja:namedGraph [
>>>       ja:graphName <https://d-nb.info/datasets/dnb-all#dataset> ;
>>>       ja:graph <#dnb-all>
>>>   ];
>>>   ja:namedGraph [
>>>       ja:graphName <https://d-nb.info/datasets/zdb#dataset> ;
>>>       ja:graph <#zdb>
>>>   ];
>>>   .
>>> <#authorities> a tdb2:GraphTDB ;
>>>   tdb2:dataset <#dataset-authorities> .
>>> <#bib> a tdb2:GraphTDB ;
>>>   tdb2:dataset <#dataset-bib> .
>>> <#dnb-all> a tdb2:GraphTDB ;
>>>   tdb2:dataset <#dataset-dnb-all> .
>>> <#zdb> a tdb2:GraphTDB ;
>>>   tdb2:dataset <#dataset-zdb> .
>>> 
>>> <#dataset-authorites> a tdb2:DatasetTDB ;
>>>   tdb2:location "/home/svensson/fuseki-data/dnb/authorities/" .
>>> <#dataset-bib> a tdb2:DatasetTDB ;
>>>   tdb2:location "/home/svensson/fuseki-data/dnb/bib/" .
>>> <#dataset-dnb-all> a tdb2:DatasetTDB ;
>>>   tdb2:location "/home/svensson/fuseki-data/dnb/dnb-all/" .
>>> <#dataset-zdb> a tdb2:DatasetTDB ;
>>>   tdb2:location "/home/svensson/fuseki-data/dnb/zdb/" .
>>> 
>>> When I start Fuseki, I get the following error message:
>>> 
>>> [2019-01-15 11:14:13] Server     ERROR Exception in initialization: the root
>> file:///home/svensson/apache-jena-fuseki-
>> 3.10.0/run/configuration/service1.ttl#authorities has no most specific type 
>> that is a
>> subclass of ja:Object
>>> [2019-01-15 11:14:13] WebAppContext WARN  Failed startup of context
>> o.e.j.w.WebAppContext@46044faa{Apache Jena Fuseki
>> Server,/,file:///home/svensson/apache-jena-fuseki-3.10.0/webapp/,UNAVAILABLE}
>>> org.apache.jena.assembler.exceptions.NoSpecificTypeException: the root
>> file:///home/svensson/apache-jena-fuseki-
>> 3.10.0/run/configuration/service1.ttl#authorities has no most specific type 
>> that is a
>> subclass of ja:Object
>>> doing:
>>>   root: file:///home/svensson/apache-jena-fuseki-
>> 3.10.0/run/configuration/service1.ttl#dnb with type:
>> http://jena.hpl.hp.com/2005/11/Assembler#RDFDataset assembler class: class
>> org.apache.jena.sparql.core.assembler.DatasetAssembler
>>> 
>>> Have I missed something obvious?
>>> 
>>> Thanks in advance,
>>> 
>>> Lars
> 

Reply via email to