How to get min/max and avg lengths of text field?

I have an index with the following mapping:

        "properties": {
            "content": {
                "type":  "text",                
            },
            "ar_name": {
                "type": "text"
            }

        }

I want to get statistics (min length, max length and average length) to the content
field.

How can I do it ?

>Solution :

The string_stats aggregation provides that support but only for keyword fields. Since your content field is of type text, I assume it contains free-text that is not really suitable as keyword.

If that’s the case, I would suggest that you stored the length of the content field in another integer field (e.g. content_length) that you can then use in a stats aggregation that would return you the metrics you expect.