select
  inst_id,                                 -- INST_ID NUMBER
  id,                                      -- FUNC_ID NUMBER
  argnum,                                  -- ARGNUM NUMBER
  case                                     -- DATATYPE VARCHAR2(8) 
     when dtype = 0 
     then 'UNKNOWN' 
     when dtype = 1 
     then 'NUMERIC' 
     when dtype = 2 
     then 'STRING' 
     when dtype = 3 
     then 'DATETYPE' 
     when dtype = 4 
     then 'BINARY' 
     when dtype = 5 
     then 'EXPR' 
     when dtype = 6 
     then 'ARG 1' 
     when dtype = 7 
     then 'ARG 2' 
     when dtype = 8 
     then 'ARG 3' 
     else 'INVALID' end,
  descr                                    -- DESCR VARCHAR2(30)
from
  x$oparg