Aggregate Streams aggregate input data. In the input pipe a grouping is defined, and an output record is produced for each key value combination that is produced by the grouping.
Aggregate Streams are configured through the stream form.
Note that simply simple aggregations are better performed using aggregate pipes.
Aggregate Streams are functionally identical to merge streams, but by convention, when there is only one input, an Aggregate Stream is used to display - this displays as a streamFunctionAggregate16x16.png on the model view - . Often this often helps to clarify the purpose of the stream in the processmodel.