Thanks Visolve, Peter, This is a serious matter, because: - within a row: 1 + NULL = NULL - across rows with SUM(): 1 + NULL = 1
I know the manual says that group functions ignore NULL values (12.10.1), but it also says: Conceptually, NULL means "a missing unknown value" (3.3.4.6). IMHO a NULL with any value should always add to NULL. I was hoping for an option / setting to change NULL behaviour. Well, I will try the suggested alternatives. Thanks, Cor