Counting all docs in an Elasticsearch nested mapping index

console example.txt

# ensure the test index is deleted if we've tested previously
DELETE /my_index/

# create the index with two nested fields
PUT my_index
{
  "mappings": {
    "my_type": {
      "properties": {
        "user": {
          "type": "nested" 
        },
        "contact_details": {
          "type": "nested" 
        }
      }
    }
  }
}


# Run this post several times to create a few docs
POST my_index/my_type/
{
  "some test field": "testing 123",
  "another test field": "some regular field string",
  "user": [
    {
      "first": "John",
      "last": "Smith"
    },
    {
      "first": "Alice",
      "last": "White"
    }
  ],
  "contact_details": [
    {
      "Name": "John Smith",
      "Phome": "555-935-901"
    },
    {
      "Name": "Alice White",
      "Email": "alice.white@somemail.yurgle"
    }
  ]
}


# take a look at the docs we've created
GET /my_index/_search


# Now run a match_all query with an agg per nested field
# The total docs in the index is the sum of the hits and the aggregations.
GET /my_index/_search
{
    "query" : {
        "match_all": {}
    },
    "size": 0, 
    "aggs" : {
        "user" : {
            "nested" : {
                "path" : "user"
            }
        },
        "contact_details": {
          "nested": {
            "path": "contact_details"
          }
        }
    }
}

# count only counts the parent docs of a nested mapping
GET /my_index/_count

# the cat api counts all the docs including the nested docs as separate docs in the count.
# Verify your nested aggregation sum count is the same as the cat api docs count.
GET /_cat/indices/my_index?v