For a UDSF, you write a function that is called once per row and returns one value per row. The function name used in the SQL statement and the function name in the .so file can be the same (although they do not have to be).
For a UDSF, you write a function that is called once per row and returns one value per row. The function name used in the SQL statement and the function name in the .so file can be the same (although they do not have to be).