Test functionality of doc-value-only fields introduced in Elastic ver 8

doc-value-only-test.json

# TEST: Use case of doc-value-only fields on search and aggregation.
# CONCLUSION: Aggregations and search are both readily supported on fields with doc_values disabled. There is a performance impact but storage is better. Ideally use this feature where search speed isn't important.
# DOCUMENTATION: https://www.elastic.co/guide/en/elasticsearch/reference/current/doc-values.html
# NOTES: Included a disabled doc value ("doc_values: false") field for reference to aggs. Aggs do not work on them.

# Copy/paste this into Kibana > Dev Tools to try it out yourself.

# Mapping doc-value-only fields, session_id and integer are both doc-value-only. 
PUT my-index-000001
{
  "mappings": {
    "properties": {
      "status_code": { 
        "type":       "keyword"
      },
      "session_id": { 
        "type":       "keyword",
        "doc_values": false
      },
      "meeting_id": { 
        "type":       "keyword",
        "index": false
      },
      "integer": {
        "type": "long",
        "index": false
      }
    }
  }
}

# Put some data in it.
PUT my-index-000001/_bulk
{"create": {}}
{"status_code": "0105", "session_id": "365", "meeting_id": "117", "integer": 3}
{"create": {}}
{"status_code": "0106", "session_id": "365", "meeting_id": "117", "integer": 4}
{"create": {}}
{"status_code": "0107", "session_id": "365", "meeting_id": "117", "integer": 5}
{"create": {}}
{"status_code": "0108", "session_id": "314", "meeting_id": "118", "integer": 7}
{"create": {}}
{"status_code": "0109", "session_id": "375", "meeting_id": "121", "integer": 11}
{"create": {}}
{"status_code": "0110", "session_id": "375", "meeting_id": "121", "integer": 14}

# Simple terms search, works.
GET my-index-000001/_search
{
  "query": {
    "terms": {
      "session_id": [ "365", "375" ],
      "boost": 1.0
    }
  }
}

# Simple match search, works.
GET my-index-000001/_search
{
  "query": {
    "match": {
      "session_id": "365"
    }
  }
}

# Boolean search, works.
GET my-index-000001/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "match": {
            "session_id": "375"
          }
        },
        {
          "match": {
            "integer": 14
          }
        }
      ]
    }
  }
}

# Boolean search with filter, works.
GET my-index-000001/_search
{
  "query": {
    "bool": {
      "should": [
        {
          "match": {
            "integer": "14"
          }
        }
      ],
      "filter": [
        {
          "term": {
            "session_id": "375"
          }
        }
      ]
    }
  }
}

# Bucket agg on meeting_id, does work as doc_value_only.
GET my-index-000001/_search
{
  "size": 0,
  "aggs": {
    "Count": {
      "terms": {
        "field": "meeting_id",
        "size": 10
      }
    }
  }
}

# Bucket agg on session_id, does not work because doc_values is disabled.
GET my-index-000001/_search
{
  "aggs": {
    "Count": {
      "terms": {
        "field": "session_id",
        "size": 10
      }
    }
  }
}

# Metric agg, works.
GET my-index-000001/_search
{
  "size": 0,
  "aggs": {
    "Sum": {
      "sum": {
        "field": "integer"
      }
    }
  }
}