Oracle: DBMS_TABLE_DATA

create table tq84_td (
    id  number(5),
    txt varchar2(20)
);
 
insert into tq84_td values (42, 'hello world');
commit;
 
select
   dump( id, 16), -- Typ=2 Len=2: c1,2b
   dump(txt, 16)  -- Typ=1 Len=11: 68,65,6c,6c,6f,20,77,6f,72,6c,64
from
   tq84_td;
 
declare
   bytes_of_row  blob;
   row_id        rowid;
begin
 
   select rowid into row_id from tq84_td where id = 42;
 
   dbms_table_data.get_bytes_for_row(
        schema_name  => user,
        table_name   =>'TQ84_TD',
        row_id       => row_id,
        column_data  => bytes_of_row
   );
  
   dbms_output.put_line(rawtohex(bytes_of_row));
--
-- C12B68656C6C6F20776F726C64
--
end;
/