[ML] Transforms: Group by and aggregation options.

[walterra]

Meta issue to track progress on UI implementations of group-by and aggregation options.

Docs reference: https://www.elastic.co/guide/en/elasticsearch/reference/current/put-transform.html

Transforms use composite aggs under the hood, so its options are available for group by and aggs configs. https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-composite-aggregation.html

Pivot

group by

x-pack/plugins/transform/public/app/common/pivot_group_by.ts

• Date Histogram
• Geotile Grid
• Histogram
• Terms

group by options

• missing_bucket (added support for advanced editor in [ML] Transforms: Support for missing_bucket in transform advanced pivot editor #85758, rest of UI support in [ML] Transforms: Adds missing bucket checkbox to group by popover form. #91650)
• script

The order, pagination, size, options from composite aggs are implementation details of transforms and not applicable for configurations.

aggs

x-pack/plugins/transform/common/types/pivot_aggs.ts

• Average
• Bucket script
• Bucket selector
• Cardinality
• Filter
• Geo bounds
• Geo centroid [ML] Data frames having geo_centroid agg available in UI #38528
• Geo line (ES PR [Transform] add support for geo_line aggregation in pivot function elasticsearch#69299)
• Max
• Median absolute deviation
• Min
• Missing
• Percentiles
• Range (ES PR [Transform] Support range aggregation in transform elasticsearch#86501)
• Rare Terms
• Scripted metric
• Sum
• Terms
• Value count
• Weighted average

Latest

• Support for latest added in [Transform] Add support for latest function #85784.

[walterra]

Related discussion about transform UI: #83267