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 ?

CodePudding user response：

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.

CodePudding user response：

If you want to keep field as text or you don't want to change the mapping, you can achieve this by a script in aggregation. Here is an example query:

{
  "size": 0,
  "aggs": {
    "min": {
      "min": {
        "script": {
          "source": """
            return doc['content'].value.length();
          """
        }
      }
    },
    "max": {
      "max": {
        "script": {
          "source": """
            return doc['content'].value.length();
          """
        }
      }
    },
    "avg": {
      "avg": {
        "script": {
          "source": """
            return doc['content'].value.length();
          """
        }
      }
    }
  }
}