Similarity plugin for elastic search 2.4 to ignore the IDF (inverse document frequency).
Sets idf to a static 1.0f.
Tested for elastic search 2.4.1 and Java 1.7.
Use ./install.sh to build and install plugin. Eventually set ES_DIR in install.sh to the appropriate directory.
Make sure you add similarity to the index' settings:
"similarity": {
"ignore-idf-similarity": {
"type": "ignoreidfsimilarity"
}
}
and use it in the mappings of the index:
"fieldname": {
"type": "string",
"similarity": "ignore-idf-similarity"
}