Within my calculation views I had been encountering problems properly aggregating the measures, when certain attributes were excluded from the result set. An SAP consultant recommended setting the attributes' KeepFlag property to True; that resolved the problem, but I'm not sure why.
The help feature within HANA Studio doesn't mention the Keep Flag property. I haven't been able to find much information about this property online, either.
Exception aggregation modeling with Graphical Calc view states:"The Keep flag will always add [the specified] columns in the group by clause even if they are not selected in the query." This is a good start; however, is there any additional documentation regarding this property?