select * from (
select c.table_name, co.column_name, co.position column_position
from user_constraints c, user_cons_columns co
where c.constraint_name = co.constraint_name
and c.constraint_type = 'R'
minus
select ui.table_name, uic.column_name, uic.column_position
from user_indexes ui, user_ind_columns uic
where ui.index_name = uic.index_name
)
order by table_name, column_position;
select
a.constraint_name cons_name
,a.table_name tab_name
,b.column_name cons_column
,nvl(c.column_name,'***No Index***') ind_column
from user_constraints a
join
user_cons_columns b on a.constraint_name = b.constraint_name
left outer join
user_ind_columns c on b.column_name = c.column_name
and b.table_name = c.table_name
where constraint_type = 'R'
order by 2,1;