DUMP to HEX

DUMP function gives decimal presentation of a column contents bits.

select ch,dump(ch) dm 
from (
select 'DUMP to DEC' ch 
from dual
)
;

CH DM

DUMP to DEC Typ=96 Len=11: 68,85,77,80,32,116,111,32,68,69,67

Sometimes hexadecimal presentation would be nice

select ch
     , listagg(to_char((column_value).getnumberval(),'XX'))
        within group (order by rownum) hex 
 from (
  select ch,dump(ch) dm 
   from (
    select 'DUMP to HEX' ch 
      from dual
    )
  ) n
  ,xmltable(substr(n.dm,instr(n.dm,':')+2))
;

CH HEX

DUMP to HEX  44 55 4D 50 20 74 6F 20 48 45 58

Or maybe it is easier just to use the documented second parameter of dump function.

select ch,dump(ch,1016) dm 
 from (
  select 'DUMP to HEX' ch 
  from dual
 )
;


DUMP to HEX    Typ=96 Len=11 CharacterSet=AL32UTF8: 44,55,4d,50,20,74,6f,20,48,45,58