Database : opt
Restore  : NO

Operator : groupby2
Number   : 1
Signature: stream(Tuple) x AttrList x (NewAttr-1 x (Tuple x Data -> Data) x Data) .. (NewAttr-j  x (Tuple x Data -> Data) x Data) -> stream(Tuple(Attrlist) o Tuple([NewAttr-1: Data]..[NewAttr-j: Data]) 
Example  : query plz feed filter[.Ort = "Dresden"] groupby2[PLZ; AnzOrte: fun(t:TUPLE, i:int) i + 1::0] count
Result   : 146