It's a fair point. Null is the absence of a value. When used in a programming context it is either a pointer (which is not an integer or a float -- it's the po

It's a fair point. Null is the absence of a value. When used in a programming context it is either a pointer (which is not an integer or a float -- it's the pointer to the absence of an integer or a float. It is not equivalent to 0 or 0.0 or ""), a magic number (specifically for chars), or a special structure with a flag. This more correctly would be "Default=0 Island". A database that doesn't have a nullable field would be the one where you'd have 0.0 as the defaults.