What is the sample size here? I mean, for a low number of literals it's obvious that String containment check in Java isn't that slow. The difference will most likely come from a large scan over literals with containment check whereas with a Lucene index - which is basically an inverted index - it's obviously more efficient to lookup terms for the documents.
On 04.01.21 05:56, Deepali Singhavi wrote: > Hi, > > I am trying to implement indexing for Fuseki using > Lucene/ElasticSearch using an assembler configuration file (attaching > file for reference) but there is no improvement in performance > (performance without index is better than with index). > > I am using sample data from *films.ttl* file. > > *Sample Query * > PREFIX text: <http://jena.apache.org/text#> > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > select ?subject ?object > WHERE { > # Without Index > #?subject rdfs:label ?object . > #FILTER contains(?object,"City") > #With Index > ?subject text:query (rdfs:label "city"). > ?subject rdfs:label ?object . > } > > *Performance:* > > No of Triples > > > > No of Runs > > > > Without Index > > > > Lucene Index > > > > ElasticSearch Index > > 6918 > > > > 1 > > > > 16ms > > > > 18ms > > > > 19ms > > 2 > > > > 29ms > > > > 32ms > > > > 32ms > > 3 > > > > 22ms > > > > 23ms > > > > 21ms > > 4 > > > > 22ms > > > > 14ms > > > > 53ms > > 5 > > > > 15ms > > > > 19ms > > > > 18ms > > > Please let me know if any other information is required from my side > and please suggest how I can improve performance. > > Regards, > Deepali >
