GroupBy node is possibly my favourite node, and one of the most powerful.
It does however, have a limitation which I find quite frustrating.
Its that the aggregation section cannot be used effectively on table structures which change (i.e. number of columns varies depending on input file into workflow).
If user doesnt what to apply specific aggreations to specific column names, Is there a possibility to implement under the Aggregation tab, some generic placeholders for handling different types of columns in which user selects an aggregation for this column type. i.e. So when new columns appear, a user selected aggregation is automatically applied,
i.e. For Double or Integer, it applies Mean,
and For String it applies First.