Bucket script aggregation

Bucket script aggregation #

A parent pipeline aggregation computing arithmetic on a bucket’s own metrics — the script references sibling metrics by name through params and its result becomes a new per-bucket value. It is the SQL SELECT a / b AS c of the aggregation world: one derived column, evaluated once per bucket over values the bucket already holds.

"avg_order": {
  "bucket_script": {
    "buckets_path": { "r": "revenue", "n": "orders" },
    "script": "params.r / params.n"
  }
}

How it works #

bucket_script is declared inside the multi-bucket aggregation it decorates, next to the metrics it consumes. After the buckets are built, the engine resolves each named path against every bucket, binds the numbers into the script’s scope, evaluates the script once, and inserts its result under the pipeline’s own name — the response shape buckets[i].avg_order.value.