Setting Default Graph has no effect

Tools & Utilities
1

Hi,

I wish to restrict this URI Burner query to WordNet named graph only. Is the SPARQL syntax correct (it was generated by FCT)? If the syntax is correct, why are there items in the result set that do not logically belong to WordNet named graph? This FCT article states:

graph="graph_iri" installed default is to search in all graphs, but system defaults may override this

Is this behavior implemented at the SPARQL processor or at the FCT service endpoint? Also, is it the case that Virtuoso’s system default is overriding the graph set in the SPARQL, so that input:default-graph-uri has no effect?

2

This seems to affect only the list-count view type. The Categories and Properties seem to filter properly to WordNet Classes and Properties. The diff between the view@type=properties query (left) and view@type=list-count query (right) shows that the select distinct ?g part is the only real difference, but when I remove that wrapper, the results still seem out-of-scope:

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image.png2856×830 120 KB

3

For the uriburner.com query:

define input:default-graph-uri <http://www.ontologyportal.org/WordNet#>     
select ?s1 as ?c1 count (*) as ?c2 
where
  { select distinct ?s1 ?g  
    { quad map virtrdf:DefaultQuadMap 
      { graph ?g 
        { ?s1 <http://www.w3.org/2000/01/rdf-schema#label> ?o1 . 
          ?o1 bif:contains  '(POLAR AND BEAR)'  . 
  } } } } 
group by ?s1 
order by desc 2 
limit 30  
offset 0

if you remove the graph ?g specifier, i.e. –

define input:default-graph-uri <http://www.ontologyportal.org/WordNet#>
select ?s1 as ?c1 count (*) as ?c2 
where
  { select distinct ?s1
    { quad map virtrdf:DefaultQuadMap
      { ?s1 <http://www.w3.org/2000/01/rdf-schema#label> ?o1 . 
        ?o1 bif:contains  '(POLAR AND BEAR)'  . 
  } } } 
group by ?s1 
order by desc 2 
limit 30  
offset 0

but then the http://www.ontologyportal.org/WordNet# on uriburner.com is empty thus no results are returned, query …

4

Thank you Hugh, this is indeed the case.

5

FYI, we discovered that the proxy was submitting all request to LOD, regardless of the domain of the target data server, due to a bug in configuration external proxy library. This issue has been fixed. Thank you for helping us detect this.

6

@hwilliams

Here are two examples where I attempt to restrict the named graph, query 1 and query 2. As you can see, 1) the results are the same for both, and 2) there are superfluous items in each result set.

This is also tested by choosing a “Library” in the PoC UI, for instance.