I don't know of any database that supports multi column count. But even if one did, count(*) does not have the semantics that you would expect from that. If the

I don't know of any database that supports multi column count. But even if one did, count(*) does not have the semantics that you would expect from that. If the semantics were equivalent to expanding the column list then count(*) with a single nullable column would return the number of non-null values. But instead it is defined to return the number of rows regardless of context, being equivalent to count() or count(1).