Hi Svetlana, I know it is a very old post, but I think it is a good place for my questions. I'm trying to understand "Aggregate" specification: 1) when "groupBy" is provided and it is not null, should sum, max, min and average be calculated based on the size of the different groups ? 2) what should be the data type of an Aggregate multiset or count with groupBy? It seems to me a map, but PMML does not have such datatype 3) without "sqlWhere", the multiset just return a some set of items, where, inside...