Scalar. Returns a value larger than that returned by the previous call. The first call returns 1.
nextval()
The first call to the function returns 1, and then each subsequent call returns a value larger than that returned by the previous call. The increase in the values is not necessarily one; it may be larger. Each call to nextval() returns a new value, even if it is called more than once in a single statement. The function takes no arguments, and the function returns a long.
The first call to nextval() returns 1. Calling nextval() a second time could return 14, for example.