--
-- tree_ancestor_keys/1
--
create or replace function tree_ancestor_keys(
  bit varying
) returns varbit as $$


  select tree_ancestor_keys($1, 1)

$$ language plpgsql;


--
-- tree_ancestor_keys/2
--
create or replace function tree_ancestor_keys(
  bit varying,
  integer
) returns varbit as $$

  select tree_ancestor_key($1, $2)
  union
  select tree_ancestor_keys($1, $2 + 1)
  where $2 < tree_level($1)
$$ language plpgsql;