Elasticsearch で複数のフィールドでグループ化してカウント

Elasticsearch で複数のフィールドでレコード数をカウントする方法のメモ。

■クエリ

{
  "query": {
    "match_all": {}
  },
  "aggs": {
    "count_name_value": {
      "multi_terms": {
        "terms": [{ "field": "name" }, { "field": "value" }],
        "size": 2
      }
    }
  },
  "_source": ["name", "value"],
  "size": 0
}

■実行結果

{
  "took" : 23,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 6,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "count_name_value" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 1,
      "buckets" : [
        {
          "key" : [
            "3",
            "3"
          ],
          "key_as_string" : "3|3",
          "doc_count" : 3
        },
        {
          "key" : [
            "2",
            "2"
          ],
          "key_as_string" : "2|2",
          "doc_count" : 2
        }
      ]
    }
  }
}