with q(n) as (
  select 0 from dual union select 1 from dual union select 2 from dual union 
  select 3 from dual union select 4 from dual union select 5 from dual union 
  select 6 from dual union select 7 from dual union select 8 from dual union select 9 from dual
),
q2 as (
  select 
    d0.n||d1.n||d2.n||d3.n||d4.n||d5.n||d6.n||d7.n||d8.n||d9.n permutation
  from q d0
  join q d1 on d1.n not in (d0.n)
  join q d2 on d2.n not in (d0.n,d1.n)
  join q d3 on d3.n not in (d0.n,d1.n,d2.n)
  join q d4 on d4.n not in (d0.n,d1.n,d2.n,d3.n)
  join q d5 on d5.n not in (d0.n,d1.n,d2.n,d3.n,d4.n)
  join q d6 on d6.n not in (d0.n,d1.n,d2.n,d3.n,d4.n,d5.n)
  join q d7 on d7.n not in (d0.n,d1.n,d2.n,d3.n,d4.n,d5.n,d6.n)
  join q d8 on d8.n not in (d0.n,d1.n,d2.n,d3.n,d4.n,d5.n,d6.n,d7.n)
  join q d9 on d9.n not in (d0.n,d1.n,d2.n,d3.n,d4.n,d5.n,d6.n,d7.n,d8.n)
),
q3 as (
  select 
    translate('DONALD','DONALGERBT',permutation) donald,
    translate('GERALD','DONALGERBT',permutation) gerald,
    translate('ROBERT','DONALGERBT',permutation) robert
  from q2
)
select * 
from q3 
where donald+gerald=robert