This is the SKOS support for Lucene, originally written by Bernhard Haslhofer for Lucene and Solr, ported to Elasticsearch.
For more information about the original version, please see https://github.com/behas/lucene-skos
For a presentation and discussion, see http://de.slideshare.net/bhaslhofer/using-skos-vocabularies-for-improving-web-search
The Simple Knowledge Organization System (SKOS) is a model for expressing controlled structured vocabularies (classification schemes, thesauri, taxonomies, etc.). As an application of the Resource Description Framework (RDF), SKOS allows these vocabularies to be published as dereferenceable resources on the Web, which makes them easy to retrieve and reuse in applications. SKOS plays a major role in the ongoing Linked Data activities.
SKOS for Elasticsearch_ is an analyzer plugin. It takes existing SKOS concepts schemes
and performs term expansion for given documents and/or queries.
The module supports the following use cases:
Expansion of URI terms to SKOS labels: URI-references to SKOS concepts in given documents are expanded by the labels behind those concepts.
Expansion of text terms to SKOS labels: Labels in given documents, which are defined as preferred concept labels in a given SKOS vocabulary, are expanded by additional labels defined in that vocabulary.
(https://travis-ci.org/jprante/elasticsearch-analysis-skos.png)
| Elasticsearch | SKOS Plugin | Release date |
|---|---|---|
| 2.3.3 | 2.3.3.0 | Jun 15, 2016 |
| 2.3.0 | 2.3.0.0 | Apr 1, 2016 |
| 2.2.1 | 2.2.1.1 | Apr 1, 2016 |
| 2.1.1 | 2.1.1.1 | Jan 13, 2016 |
| 1.4.2 | 1.4.2.0 | Feb 5, 2015 |
./bin/plugin install http://xbib.org/repository/org/xbib/elasticsearch/plugin/elasticsearch-analysis-skos/2.3.3.0/elasticsearch-analysis-skos-2.3.3.0-plugin.zipDo not forget to restart the node after installing. You have to disable the security manager in order to get Jena to work:
./bin/elasticsearch -Des.security.manager.enabled=false./bin/plugin -install analysis-skos -url http://xbib.org/repository/org/xbib/elasticsearch/plugin/elasticsearch-analysis-skos/1.4.2.0/elasticsearch-analysis-skos-1.4.2.0.zipDo not forget to restart the node after installing.
The Maven project site is available at Github
Given the following example SKOS file ukat_examples.n3 in $ES_HOME
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix ukat: <http://www.ukat.org.uk/thesaurus/concept/> .
ukat:859 rdf:type skos:Concept ;
skos:prefLabel "Weapons" ;
skos:altLabel "Armaments" ;
skos:altLabel "Arms" ;
skos:broader ukat:5060 ;
skos:narrower ukat:18874 ;
skos:narrower ukat:7630 .
ukat:5060 rdf:type skos:Concept;
skos:prefLabel "Military equipment";
skos:altLabel "Defense equipment and supplies";
skos:altLabel "Ordnance".
ukat:18874 rdf:type skos:Concept;
skos:prefLabel "Ammunition".
ukat:7630 rdf:type skos:Concept;
skos:prefLabel "Artillery".you can use URI-based expansion like in this demonstration
curl -XDELETE 'localhost:9200/test/'
curl -XPOST 'localhost:9200/test' -d '{
"settings" : {
"index" : {
"analysis" : {
"filter": {
"skosfilter" : {
"type": "skos",
"indexName" : "ukat",
"skosFile": "ukat_examples.n3",
"expansionType": "URI"
}
},
"analyzer" : {
"skos" : {
"type" : "custom",
"tokenizer" : "keyword",
"filter" : "skosfilter"
}
}
}
}
},
"mappings" : {
"_default_" : {
"properties" : {
"subject" : {
"type" : "string",
"analyzer" : "skos",
"search_analyzer" : "standard"
}
}
}
}
}'
# index test document
curl -XPUT 'localhost:9200/test/subjects/1' -d '{
"title" : "Spearhead",
"description": "Roman iron spearhead. The spearhead was attached to one end of a wooden shaft.The spear was mainly a thrusting weapon, but could also be thrown. It was the principal weapon of the auxiliary soldier. (second - fourth century, Arbeia Roman Fort)",
"subject" : "http://www.ukat.org.uk/thesaurus/concept/859"
}'
curl -XPOST 'localhost:9200/test/_refresh'
echo
# should give one hit
curl -XGET 'localhost:9200/test/_search?pretty' -d '{
"query": {
"term" : {
"subject": "arms"
}
}
}'
echo
# should give one hit
curl -XGET 'localhost:9200/test/_search?pretty' -d '{
"query": {
"term" : {
"subject": "weapons"
}
}
}'
echo
# should give one hit
curl -XGET 'localhost:9200/test/_search?pretty' -d '{
"query": {
"term" : {
"subject": "military equipment"
}
}
}'
echo
# should give no hit
curl -XGET 'localhost:9200/test/_search?pretty' -d '{
"query": {
"term" : {
"subject": "nonsense"
}
}
}'
echoThe following settings parameters may be used in a filter of type skos
indexName - a name for SKOS index
skosFile - the name of the skos file with suffix .n3, .rdf, .ttl, .zip (mandatory)
expansionType - URI or LABEL (mandatory)
bufferSize - a buffer size for the number of words that will be checked for expansion
language - a language for the expansion
skosType - a string with space-separated terms of PREF, ALT, HIDDEN, BROADER, NARROWER, BROADERTRANSITIVE, NARROWERTRANSITIVE, RELATEDElasticsearch SKOS Plugin
Copyright (C) 2013 Jörg Prante
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.