About the Aggregate node
The Aggregate node performs functional operations against each row of data produced by the node data source. These functional
operations do not take into account the order of the parameters, and so are limited to functions dealing with input values
as an aggregate.
Figure 18. Aggregate node
The Aggregate Editor, like the Composite Node editor, creates the output schema of the aggregate node. To create the schema, you add field names to the schema and assign functions to each property.
Figure 19. Aggregate Editor
Each aggregate function takes a set of input source fields as parameter values. You select these input parameters in the Function Editor. There is no limit to the number of parameters that you can select for a function, with the exception of the Pass Through function, which passes through a single value without altering it. This makes the value available for the next consuming node in the graph.