Cumulative cardinality aggregation

Cumulative cardinality aggregation #

A parent pipeline aggregation reporting a running total of a per-bucket distinct count — typically a cardinality metric — answering “how many unique values have been counted up to and including each bucket”.

"seen_so_far": {
  "cumulative_cardinality": { "buckets_path": "buyers" }
}

How it works #

cumulative_cardinality is declared inside the multi-bucket aggregation it decorates, next to the metric it consumes. The engine walks the finished buckets in order and attaches the running total of the referenced values under the pipeline’s own name — mechanically the same accumulation as cumulative_sum; only the intended input (a per-bucket distinct count) differs.