anchor.diff:  `terms`::
   (Optional, <<search-aggregations-bucket-terms-aggregation,`terms`
   aggregation>> object)
  -Groups and stores unique values for <<keyword,keyword family>> and
  -<<number,numeric>> fields.
  +Groups documents based on unique field values.
   +
   .Properties of `terms`
   [%collapsible%open]
   ======
   `fields`::
  ++
  +--
   (Required*, string or array of strings)
  -<<keyword,Keyword family>> and <<number,numeric>> fields to store. If you
  -specify a `terms` object, this property is required.
  -+
  +Fields to store unique values for. Supports the following field types:
  +
  +* <<keyword,Keyword family>> types
  +* <<number,Numeric>> types, excluding `unsigned_long`
  +* <<text,`text`>> fields with <<fielddata-mapping-param,`fielddata`>> enabled
  +
  +If you specify a `terms` object, this property is required.
  +
   TIP: Avoid storing high-cardinality fields. High-cardinality fields can greatly
   increase the size of the resulting rollup index.
  +--
   ======
   =====
   
   `metrics`::
   (Required, object or array of objects)
  -Collects and stores metrics for <<number,numeric>> fields. You must specify at
  -least one `metrics` object.
  +Collects and stores metrics for fields. You must specify at least one `metrics`
  +object.
   +
   .Properties of `metrics` objects
   [%collapsible%open]
   =====
   `field`::
   (Required, string)
  -<<number,Numeric>> field to collect metrics for.
  -+
  -WARNING: Do not use the same fields in `histogram` and `metrics`. If you specify
  -the same field in both `histogram` and `metrics`, the rollup attempt will fail.
  +<<number,Numeric>>, <<date,`date`>>, or <<date_nanos,`date_nanos`>> field to
  +collect metrics for. `unsigned_long` fields are not supported.
  ++
  +WARNING: Do not use fields specified in `histogram` or `date_histogram`. If you
  +do, the rollup attempt will fail.
   
   `metrics`::
   (Required, string or array of strings)
  
positive.code: // tag::rollup-config[]
  `groups`::
  (Required, object)
  Aggregates and stores fields in the rollup.
  +
  .Properties of `groups`
  [%collapsible%open]
  
negative.code: <<date,`date`>> or <<date_nanos,`date_nanos`>> field containing a timestamp. If
  you're rolling up a backing index or using the {ecs-ref}[Elastic Common Schema
  (ECS)], we recommend using `@timestamp`.
  +
  WARNING: Do not use this field in `metrics`. If you do, the rollup attempt will
  fail.
  
  `calendar_interval` or `fixed_interval`::
  (Required, <<time-units,time units>>)
  