GraphDB: use similarity search with embedded repository - graphdb

Question

I have been using GraphDB's (version 9.2) similarity search from the workbench. Now I also want to use this feature for an embedded repository using graphdb-free-runtime 9.2.1. However I have no clue how this feature can be used from the APIs provided by the runtime. My questions are:
In http://graphdb.ontotext.com/documentation/standard/semantic-similarity-searches.html it is mentioned that similarity search is a plugin. However I could not find any such plugin within the runtime. Do I have to load it from some external resource? Where?
Is there any documentation or example how to create a similarity index programmatically?
Would it be an option to run the workbench as some kind of server and access the similarity search via REST API? However the REST API documentation at http://graphdb.ontotext.com/documentation/9.0/free/using-the-workbench-rest-api.html does not mention any API for similarity searches. Am I missing something?
Any hints or pointers are welcome.

Answer 1

You could add similarity plugin runtime, setting following "graphdb.extra.plugins" property to directory where similarity-plugin (you could find such into GDB instance -> dist/lib/plugins) is located , or:
-Dgraphdb.extra.plugins=directory
System.setProperty("graphdb.extra.plugins", "directory");
You may create index programmatically using SPARQL or:
to create similarity text index "allNews" execute following update:
PREFIX : <http://www.ontotext.com/graphdb/similarity/>
PREFIX inst: <http://www.ontotext.com/graphdb/similarity/instance/>
PREFIX pred: <http://www.ontotext.com/graphdb/similarity/psi/>
insert {
inst:allNews :createIndex "-termweight idf" ;
:analyzer "org.apache.lucene.analysis.en.EnglishAnalyzer" ;
:documentID ?documentID .
?documentID :documentText ?documentText .
} where {
SELECT ?documentID ?documentText {
?documentID ?p ?documentText .
filter(isLiteral(?documentText))
}
}
to delete index "allNews" execute following update:
PREFIX :<http://www.ontotext.com/graphdb/similarity/>
PREFIX inst:<http://www.ontotext.com/graphdb/similarity/instance/>
insert { inst:allNews :deleteIndex '' } where {}
to rebuild index "allNews":
PREFIX :<http://www.ontotext.com/graphdb/similarity/>
PREFIX inst:<http://www.ontotext.com/graphdb/similarity/instance/>
insert { inst:allNews :rebuildIndex '' } where {}
followed by the create query!
to list all created indexes, execute following query:
PREFIX :<http://www.ontotext.com/graphdb/similarity/>
PREFIX inst:<http://www.ontotext.com/graphdb/similarity/instance/>
select ?index ?status ?type
where {
?index :status ?status .
?index :type ?type .
}