Aggregating Index Stage

This stage has been deprecated since Fusion 2.1.

This is an index pipeline stage that aggregates incoming PipelineDocument(s) in order to enrich them with aggregation functions, or to reduce the volume of documents to be processed in subsequent pipeline stages. Scenarios that require high-throughput event ingestion can benefit from this stage, which pre-aggregates raw events inside the pipeline, in order to reduce the total number of events to be indexed.