postgresql7.1
select repeat(' ', (t.type_level - 1) * 4) as indent,
t.pretty_name, t.rel_type
from (select t2.pretty_name, t2.object_type as rel_type, tree_level(t2.tree_sortkey) - tree_level(t1.tree_sortkey) + 1 as type_level
from acs_object_types t1,
acs_object_types t2
where t2.tree_sortkey like (t1.tree_sortkey || '%')
and t2.object_type not in (select g.rel_type
from group_type_rels g
where g.group_type = :group_type)
and t1.object_type in ('membership_rel', 'composition_rel')) t,
acs_rel_types rel_type
where t.rel_type = rel_type.rel_type
and (rel_type.object_type_one = :group_type
or acs_object_type__is_subtype_p(rel_type.object_type_one, :group_type) = 't')