mapped_pages:
In order to enable the _size field, set the mapping as follows:
PUT my-index-000001
{
  "mappings": {
    "_size": {
      "enabled": true
    }
  }
}
The value of the _size field is accessible in queries, aggregations, scripts, and when sorting. It can be retrieved using the fields parameter:
# Example documents
PUT my-index-000001/_doc/1
{
  "text": "This is a document"
}
PUT my-index-000001/_doc/2
{
  "text": "This is another document"
}
GET my-index-000001/_search
{
  "query": {
    "range": {
      "_size": {                      <1>
        "gt": 10
      }
    }
  },
  "aggs": {
    "sizes": {
      "terms": {
        "field": "_size",             <2>
        "size": 10
      }
    }
  },
  "sort": [
    {
      "_size": {                      <3>
        "order": "desc"
      }
    }
  ],
  "fields": ["_size"],                <4>
  "script_fields": {
    "size": {
      "script": "doc['_size']"        <5>
    }
  }
}
_size field_size field_size fieldfields parameter to return the _size in the search response._size field in the search response.::::{admonition} Using _size in {kib}
:class: note
To use the _size field in {{kib}}, update the metaFields setting and add _size to the list of meta fields. metaFields can be configured in {{kib}} from the Advanced Settings page in Management.
::::