Bucket script aggregation context

Use a Painless script in an bucket_script pipeline aggregation to calculate a value as a result in a bucket.

params (Map, read-only)

User-defined parameters passed in as part of the query. The parameters include values defined as part of the buckets_path.

numeric

The calculated value as the result.

The standard Painless API is available.

To run this example, first follow the steps in context examples.

The painless context in a bucket_script aggregation provides a params map. This map contains both user-specified custom values, as well as the values from other aggregations specified in the buckets_path property.

This example takes the values from a min and max aggregation, calculates the difference, and adds the user-specified base_cost to the result:

 (params.max - params.min) + params.base_cost 

Note that the values are extracted from the params map. In context, the aggregation looks like this:

 GET /seats/_search { "size": 0, "aggs": { "theatres": { "terms": { "field": "theatre", "size": 10 }, "aggs": { "min_cost": { "min": { "field": "cost" } }, "max_cost": { "max": { "field": "cost" } }, "spread_plus_base": { "bucket_script": { "buckets_path": { "min": "min_cost", "max": "max_cost" }, "script": { "params": { "base_cost": 5 }, "source": "(params.max - params.min) + params.base_cost" } } } } } } } 

1. The buckets_path points to two aggregations (min_cost, max_cost) and adds min/max variables to the params map
2. The user-specified base_cost is also added to the script’s params map