CODEWITHSUNDEEP
elasticsearchrelevancefunction-query
JnBrymn
JnBrymn

Reputation: 25373

How can I multiply the score of two queries together in Elasticsearch?

In Solr I can use the query function query to return a numerical score for a query and I can user that in the context of a bf parameter something like bf=product(query('cat'),query('dog')) to multiply two relevance scores together.

Elasticsearch has search API that is generally more flexible to work with, but I can't figure out how I would accomplish the same feat. I can use _score in a script_function of a function_query but I can only user the _score of the main query. How can I incorporate the score of another query? How can I multiply the scores together?

Upvotes: 6

Views: 2284

Answers (2)

Peter Dixon-Moses
Peter Dixon-Moses

Reputation: 3209

Alternately, if you've got something in that bf that's heavyweight enough you'd rather not run it across the entire set of matches, you could use rescore requests to modify the score of the top N ranked ORIGINAL QUERY results using subsequent scoring passes with your (cat, dog, etc...) scoring-queries.

Upvotes: 1

Peter Dixon-Moses
Peter Dixon-Moses

Reputation: 3209

You could script a TF*IDF scoring function using a function_score query. Something like this (ignoring Lucene's query and length normalization):

"script": "tf = _index[field][term].tf(); idf = (1 + log ( _index.numDocs() / (_index[field][term].df() + 1))); return sqrt(tf) * pow(idf,2)"

You'd take the product of those function results for 'cat' and 'dog' and add them to your original query score.

Here's the full query gist.

Upvotes: 2

Related Questions