CREATE TABLE mydata
(
   n   NUMBER,
   v   VARCHAR2 (100)
)

BEGIN
   INSERT INTO mydata (n, v)
        VALUES (1, 'Loey and Juna');

   COMMIT;
END;

CREATE OR REPLACE FUNCTION myfunc (n_in IN mydata.n%TYPE) 
   RETURN mydata.v%TYPE 
   AUTHID DEFINER 
IS 
   l_v   mydata.v%TYPE; 
BEGIN 
   SELECT v 
     INTO l_v 
     FROM mydata 
    WHERE n = n_in; 
 
   RETURN l_v; 
END;

SELECT TO_CHAR (last_ddl_time, 'HH24:MI:SS') last_changed, status
  FROM user_objects
 WHERE object_name = 'MYFUNC'

ALTER TABLE mydata 
   MODIFY v VARCHAR2 (200)

SELECT TO_CHAR (last_ddl_time, 'HH24:MI:SS') last_changed, status 
  FROM user_objects 
 WHERE object_name = 'MYFUNC'

BEGIN 
   DBMS_OUTPUT.put_line (myfunc (1)); 
END;

SELECT TO_CHAR (last_ddl_time, 'HH24:MI:SS') last_changed, status 
  FROM user_objects 
 WHERE object_name = 'MYFUNC'