-- Code to generate random string using
-- DBMS_RANDOM.string(option, length)
-- can be used to create password

DECLARE
   TYPE     va_str IS VARRAY(5) OF VARCHAR2(10);
   v_str    va_str;
   v_idx    PLS_INTEGER := 10;
BEGIN  
  v_str := va_str('A','L','P','U','X');

  FOR idx IN v_str.FIRST..v_str.LAST LOOP

   DBMS_OUTPUT.PUT_LINE(idx||' Opt_'||v_str(idx)||
     ' = '||DBMS_RANDOM.string(v_str(idx),v_idx));

  END LOOP;
END;
/

-- Note: There can be restrictions on use of 
-- special characters in passwords (such 
-- as @, % etc. in certain systems)