WITH main_q AS
     (
        SELECT t1.ID AS ID
              ,t3.full_name AS port_full_name
              ,t1.code AS code
              ,t4.full_name AS full_name
              ,t2.lcode AS lcode
              ,t1.rate AS rate
              ,t1.device_id AS device_id
              ,t1.unit_type
          FROM tn_mult_unit t1, td_device t2, td_port t3, tg_res_naming t4
         WHERE t1.device_id = t2.ID(+)
           AND t2.ID = t4.res_id
           AND t1.status = 'Free'
           AND t1.unit_type = ANY ('LogicPort', 'ExTime')
           AND t1.rate IN ('2M', '155M', '34M')
           AND t1.subpart_id = t3.ID
           AND t3.special = 'Exchange'
           AND t3.port_type = 'SwitchRelay')
SELECT ID
  FROM main_q
 WHERE t1.unit_type = 'LogicPort'
UNION ALL
SELECT ID
  FROM main_q a, tn_mult_unit b
 WHERE unit_type = 'ExTime' AND rate = '2M' AND a.parent_id = b.ID