# Significant terms aggregation returns incorrect bg\_count value when querying index with nested objects in version 8.3.3

**URL:** <https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466>\
**Category:** Elasticsearch\
**Tags:** docker\
**Created:** [April 5, 2023, 9:11pm UTC](https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466 "2023-04-05T21:11:51Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![shimpeko](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/shimpeko/32/118252_2.png) [@shimpeko](https://discuss.elastic.co/u/shimpeko)\
**Post date:** [April 5, 2023, 9:11pm UTC](https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466/1 "2023-04-05T21:11:51Z")

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Significant terms aggregation returns incorrect bg\_count value when querying index with nested objects. The value is the same as the document counts returned by `_cat/indices` API (which returns Lucene-level doc count). I'm assuming that the result of aggregation is also incorrect as "significance" is calculated using the bg\_count.

I'd like to know if this is expected behaviour or not.

This may be an expected behaviour but, if so, it is preferable to be documented. In fact, [the document for a similar feature, significant text aggregation, says that the feature doesn't support nested objects](https://www.elastic.co/guide/en/elasticsearch/reference/6.4/search-aggregations-bucket-significanttext-aggregation.html#_no_support_for_nested_objects). So I'm wondering that situation might be the same with significant terms aggregation.

Additionally, the behaviour changed at 8.4. Starting from 8.4, the aggregation returns the correct bg\_count (the count we can confirm with the `count` API).

In version 8.3.3, the bg\_count value for Significant terms aggregation is incorrect.

```auto
GET /
{
  "name": "elastic_integration",
  "cluster_name": "elastic_integration_cci_recipe_search_svc",
  "cluster_uuid": "5JpEuResTGKBbsIyaT5xJw",
  "version": {
    "number": "8.3.3",
    "build_flavor": "default",
    "build_type": "docker",
    "build_hash": "801fed82df74dbe537f89b71b098ccaff88d2c56",
    "build_date": "2022-07-23T19:30:09.227964828Z",
    "build_snapshot": false,
    "lucene_version": "9.2.0",
    "minimum_wire_compatibility_version": "7.17.0",
    "minimum_index_compatibility_version": "7.0.0"
  },
  "tagline": "You Know, for Search"
}

PUT person
{
  "mappings": {
    "properties": {
      "name": {"type": "keyword"},
      "friends": {
        "type": "nested",
        "properties": {
          "name": {"type": "keyword"}
        }
      }
    }
  }
}
{
  "acknowledged": true,
  "shards_acknowledged": true,
  "index": "person"
}

POST person/_doc
{
  "name" : "John",
  "friends" : [{"name" : "John"}, {"name" : "Alice"}, {"name" : "Tim"}]
}
{
  "_index": "person",
  "_id": "zdIyU4cBPq5OH_vFlUEb",
  "_version": 1,
  "result": "created",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 0,
  "_primary_term": 1
}

POST /person/_search
{
  "aggs": {
    "significant_names": {
      "significant_terms": {"field": "name", "min_doc_count": 1}
      
    }
  }
}
{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1,
    "hits": [
      {
        "_index": "person",
        "_id": "zdIyU4cBPq5OH_vFlUEb",
        "_score": 1,
        "_source": {
          "name": "John",
          "friends": [
            {
              "name": "John"
            },
            {
              "name": "Alice"
            },
            {
              "name": "Tim"
            }
          ]
        }
      }
    ]
  },
  "aggregations": {
    "significant_names": {
      "doc_count": 1,
      "bg_count": 4,
      "buckets": [
        {
          "key": "John",
          "doc_count": 1,
          "score": 3,
          "bg_count": 1
        }
      ]
    }
  }
}

```

I've also tested with 7.16 and got the same result.

---

<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [April 17, 2023, 3:31am UTC](https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466/2 "2023-04-17T03:31:50Z")

</div>

Thanks for providing a detailed replica here.

I'd suggest raising this on GitHub directly so an engineer can check into it.

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<div class="post-metadata">

**Author:** ![shimpeko](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/shimpeko/32/118252_2.png) [@shimpeko](https://discuss.elastic.co/u/shimpeko)\
**Post date:** [April 18, 2023, 1:51pm UTC](https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466/3 "2023-04-18T13:51:28Z")

</div>

Thank you for the replay.

I've opened [The result of significant terms aggregation has changed after upgrading from 8.3.3 to 8.4.0 and above · Issue #95067 · elastic/elasticsearch · GitHub](https://github.com/elastic/elasticsearch/issues/95067).

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [May 16, 2023, 1:51pm UTC](https://discuss.elastic.co/t/significant-terms-aggregation-returns-incorrect-bg-count-value-when-querying-index-with-nested-objects-in-version-8-3-3/329466/4 "2023-05-16T13:51:33Z")

</div>

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