In Elasticsearch facing an issue in an aggregation query. The issue is as follow,

I am asking for two different aggs in the same query. The first is “show me the doc counts for subject.label for these specific values,” and the second is “show me the doc counts for the 5 most common values within subject.label.”

The query tried,

POST my_index/search
{
  "query": {
    "match_all": {}
  },
  "size": 0,
  "aggs": {
    "selected": {
      "terms": {
        "field": "subject.label",
        "include": [ "Buddhist art" ],
        "order": { "_count": "desc" },
        "size": 5
      }
    },
    "subject": {
      "terms": {
        "field": "subject.label",
        "order": { "_count": "desc" },
        "size": 5
      }
    }
  }
}

Got the below result

{
  "took" : 5,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 10000,
      "relation" : "gte"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "userFacets" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "Buddhist art",
          "doc_count" : 12
        }
      ]
    },
    "subject" : {
      "doc_count_error_upper_bound" : 11,
      "sum_other_doc_count" : 1005,
      "buckets" : [
        {
          "key" : "Architecture",
          "doc_count" : 88
        },
        {
          "key" : "Painting",
          "doc_count" : 80
        },
        {
          "key" : "Berkeley (Calif.)",
          "doc_count" : 25
        },
        {
          "key" : "Buddhist art",
          "doc_count" : 11
        },
        {
          "key" : "Church architecture",
          "doc_count" : 10
        }
      ]
    }
  }
}

How can the value for Buddhist art be 12 in the first agg result and 11 in the second? It’s a single agg query on a single index. (There are, in fact, 12 docs with a subject.label value of “Buddhist art”.).

(This example i have taken from one more post https://discuss.elastic.co/t/different-aggregation-count-for-the-same-value/324566)

Thank you.