ElasticSearch: aggregation on _score field?

by

Note: The original answer is now outdated in terms of the latest version of Elasticsearch. The equivalent script using Groovy scripting would be:

{
    ...,
    "aggregations" : {
        "grades_stats" : { 
            "stats" : { 
                "script" : "_score" 
            } 
        }
    }
}

In order to make this work, you will need to enable dynamic scripting or, even better, store a file-based script and execute it by name (for added security by not enabling dynamic scripting)!

You can use a script and refer to the score using doc.score. More details are available in ElasticSearch’s scripting documentation.

A sample stats aggregation could be:

{
    ...,
    "aggregations" : {
        "grades_stats" : { 
            "stats" : { 
                "script" : "doc.score" 
            } 
        }
    }
}

And the results would look like:

"aggregations": {
    "grades_stats": {
        "count": 165,
        "min": 0.46667441725730896,
        "max": 3.1525731086730957,
        "avg": 0.8296855776598959,
        "sum": 136.89812031388283
    }
}

A histogram may also be a useful aggregation:

"aggs": {
    "grades_histogram": {
        "histogram": {
            "script": "doc.score * 10",
            "interval": 3
        }
    }
}

Histogram results:

"aggregations": {
    "grades_histogram": {
        "buckets": [
            {
               "key": 3,
               "doc_count": 15
            },
            {
               "key": 6,
               "doc_count": 103
            },
            {
               "key": 9,
               "doc_count": 46
            },
            {
               "key": 30,
               "doc_count": 1
            }
        ]
    }
}

More Related Contents:

  1. Elasticsearch replication of other system data?
  2. How to search for a part of a word with ElasticSearch
  3. no [query] registered for [filtered]
  4. elasticsearch bool query combine must with OR
  5. ES keeps returning every document
  6. ElasticSearch – Return Unique Values
  7. Make elasticsearch only return certain fields?
  8. Remove duplicate documents from a search in Elasticsearch
  9. Elasticsearch 2.1: Result window is too large (index.max_result_window)
  10. Max limit on the number of values I can specify in the ids filter or generally query clause?
  11. How to update multiple documents that match a query in elasticsearch
  12. Elasticsearch searchable synthetic fields
  13. Why do I need “store”:”yes” in elasticsearch?
  14. Change default mapping of string to “not analyzed” in Elasticsearch
  15. How to not-analyze in ElasticSearch?
  16. Save Spark Dataframe into Elasticsearch – Can’t handle type exception
  17. elasticsearch – what to do with unassigned shards
  18. Elasticsearch vs Cassandra vs Elasticsearch with Cassandra
  19. How to retrieve unique count of a field using Kibana + Elastic Search
  20. FIELDDATA Data is too large
  21. Can We Retrieve Previous _source Docs with Elastic Search Versions
  22. Elasticsearch, Tire, and Nested queries / associations with ActiveRecord
  23. ElasticSearch: Unassigned Shards, how to fix?
  24. Content-Type header [application/x-www-form-urlencoded] is not supported on Elasticsearch
  25. Elasticsearch, Failed to obtain node lock, is the following location writable
  26. low disk watermark [??%] exceeded on
  27. Elasticsearch – set max_clause_count
  28. How to bind Elasticsearch 2.0 on both Loopback and Non-Loopback interfaces?
  29. How to use the official docker elasticsearch container?
  30. Remove a field from a Elasticsearch document

Leave a Comment