Re: "not in a transaction", but only sometimes

[Andy Seaborne]

On 12/09/2019 16:40, Laura Morales wrote:
      <#dataset> rdf:type         tdb:DatasetTDB ;
          tdb:location "DB" ;
          tdb:unionDefaultGraph true ;
          .

The dataset can have a ja:context setting and that can be the one for
query union graph.  Not "?default-graph-uri=" which is protocol and per
query call.


Is there an equivalent of "tdb:unionDefaultGraph true" for a RDFDataset?

I'm afraid not. It's an omission. Each implementation needs it's own way 
unionDefaultGraph.


Putting the union graph <urn:x-arq:UnionGraph> from a TDB as the default 
graph of a genaral dataset might work but I'm not seeing an advantage to 
doing this.

But as so as its "union graph" of mixed storages, it is back to the 
original situation of transactions across different systems.

    Andy

I'm thinking of a property that can be set in the assembler file instead of using 
"?default-graph-uri=urn:x-arq:UnionGraph"? Perhaps something like

     :dataset a ja:RDFDataset ;
         # Use the union (of the named graphs) as default graph
         ja:unionDefaultGraph true ;

         ja:namedGraph
            [ ja:graphName      <http://example.org/name1> ;
              ja:graph          <#model1> ] ;
         ja:namedGraph
            [ ja:graphName      <http://example.org/name2> ;
              ja:graph          <#model2> ] ;
         ...