将外部文本数据索引到 GraphDB 中的 lucene 索引

Question

Is it possible to index external to RDF data? Like in RDF there is a triple with the object as a link to an external file. Can the content of this file be indexed instead of the link value?

Answer 1

Absolutely. Lucene is a core part of GraphDB and it offers the standard functionality which comes with a standalone Lucene. The data will have to be parametrized as a String literal. <http://www.example.org/> rdfs:label "An example webpage url."@EN . Then you can configure a Lucene Index:

PREFIX luc: <http://www.ontotext.com/owlim/lucene#>
INSERT DATA {
  luc:index luc:setParam "uris" .
  luc:include luc:setParam "literals" .
  luc:moleculeSize luc:setParam "1" .
  luc:includePredicates luc:setParam "http://www.w3.org/2000/01/rdf-schema#label" .
}

And once you have the configuration, you can create the index.

PREFIX luc: <http://www.ontotext.com/owlim/lucene#>
INSERT DATA {
   luc:myTestIndex luc:createIndex "true" .
}

And, given the index and your data, you can query it.

PREFIX luc: <http://www.ontotext.com/owlim/lucene#>
SELECT * {
  ?subj luc:myTestIndex "web*"
}

Since you are asking about the subject of something which contains the string web*, you'll get <http://www.example.org/> . If you had other triples linking to this one, they might have also appeared.

More information about the way in which GraphDB interacts with Lucene and its Full-Text-Search capabilities can be found within the GraphDB documentation.

Answer 2

I suspect that the answer above misunderstood the question. The question refers to external content - ie, if GraphDB's Lucene is able to index the content available at http://example.org , rather than the RDF literal associated with it (and then return in searches the triple pointing to that content).

From what I was able to try no, this is not currently supported.