CREATE OR REPLACE FUNCTION ORGPOLV2.resize_img (i_cod_op INTEGER)
      RETURN blob
   IS
      v_photo     blob ;
   BEGIN

     select img_simbolo_op
      into v_photo
      from tbl_op
      where cod_op=i_cod_op for update;

     ordimage.process(v_photo, 'maxScale=32 32');

 update tbl_op set img_simbolo_op = v_photo where cod_op=0;
--
commit;

    select img_simbolo_op
    into v_photo
    from tbl_op
    where cod_op=0;


      RETURN v_photo;
   END resize_img;
/

ORA-14551: cannot perform a DML operation inside a query
ORA-06512: at "RESIZE_IMG", line 10