Ordering Aggregation Buckets by Score

Question

Is it possible to order the aggregation bucket by score?

"aggs": {
    "UnitAggregationBucket": {
      "terms": {
        "field": "unitId",
        "size": 10,
        /* "order": order by max score documents per bucket */
      }
    }
  }

I have seen this document which explains the default order is doc_count, but I cannot find out if it is possible and how to order the buckets by score.

Answer 1

Yes, it is possible to do that like this:

{
  "size": 0,
  "query": {
    ...
  },
  "aggs": {
    "UnitAggregationBucket": {
      "terms": {
        "field": "unitId",
        "size": 10,
        "order": {
          "score": "desc"
        }
      },
      "aggs": {
        "score": {
          "max": {
            "script": "_score"
          }
        }
      }
    }
  }
}