with trim as (
    select *, replace(emp_first_name, ' ', '') as surname, replace(emp_last_name, ' ', '') as name
    from emp
)
, cnt as (
select *, count(*) over (partition by surname, name) as num
from trim
where valid_flg = '1'
)
select emp_code as CODE, emp_last_name as SURNAME, emp_first_name as NAME
from cnt
where num > 1
order by surname asc, name asc, emp_code asc