anchor.diff:  }
   ----
   
  -You can update or remove runtime fields at any time. To replace an existing runtime field, add a new runtime field to the mappings with the same name. To remove a runtime field from the mappings, set the value of the runtime field to `null`:
  -
  - [source,console]
  - ----
  - PUT my-index/_mapping
  - {
  -   "runtime": {
  -     "day_of_week": null
  -   }
  +[[runtime-fields-scriptless]]
  +==== Define runtime fields without a script
  +You can define a runtime field in the mapping definition without a
  +script. At query time, {es} looks in `_source` for a field with the same name
  +and returns a value if one exists. If a field with the same name doesn’t
  +exist, the response doesn't include any values for that runtime field.
  +
  +[source,console]
  +----
  +PUT my-index/
  +{
  +  "mappings": {
  +    "runtime": {
  +      "day_of_week": {
  +        "type": "keyword"
  +      }
  +    }
  +  }
  +}
  +----
  +
  +[[runtime-updating-scripts]]
  +==== Updating and removing runtime fields
  +
  +You can update or remove runtime fields at any time. To replace an existing
  +runtime field, add a new runtime field to the mappings with the same name. To
  +remove a runtime field from the mappings, set the value of the runtime field to
  +`null`:
  +
  +[source,console]
  +----
  +PUT my-index/_mapping
  +{
  + "runtime": {
  +   "day_of_week": null
    }
  - ----
  -
  -[[runtime-updating-scripts]]
  -.Updating and removing runtime fields
  +}
  +----
  +//TEST[continued]
  +
  +.Downstream impacts
   ****
  -
   Updating or removing a runtime field while a dependent query is running can return
   inconsistent results. Each shard might have access to different versions of the
   script, depending on when the mapping change takes effect.
  
positive.code: runtime field from a search request to the index mapping by moving the field
  definition from `runtime_mappings` in the search request to the `runtime`
  section of the index mapping.
  
  [[runtime-fields-scriptless]]
  ==== Define runtime fields without a script
  You can define a runtime field in the mapping definition without a
  script. At query time, {es} looks in `_source` for a field with the same name
  and returns a value if one exists. If a field with the same name doesn’t
  exist, the response doesn't include any values for that runtime field.
  
  [source,console]
  ----
  PUT my-index/
  {
    "mappings": {
      "runtime": {
        "model_number": {
          "type": "keyword"
        }
      }
    }
  }
  ----
  
  [[runtime-override-values]]
  === Override field values at query time
  
negative.code: fail if you remove or update the field. For example, a bar chart visualization
  that uses a runtime field of type `ip` will fail if the type is changed
  to `boolean`, or if the runtime field is removed.
  ****
  
  [[runtime-search-request]]
  