norms

Norms store various normalization factors that are later used at query time in order to compute the score of a document relatively to a query.

Although useful for scoring, norms also require quite a lot of disk (typically in the order of one byte per document per field in your index, even for documents that don’t have this specific field). As a consequence, if you don’t need scoring on a specific field, you should disable norms on that field. In particular, this is the case for fields that are used solely for filtering or aggregations.

You can't change the norms setting of an existing field. The update mapping API rejects the request.

To turn off norms, set norms to false when you create the index:

PUT my-index-000001
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text",
        "norms": false
      }
    }
  }
}

To turn off norms on a field that already has data, use one of these options:

Update the index template, then roll over the data stream. Only new backing indices get the change; existing data keeps its norms.
Reindex into a new index or data stream that has norms set to false.