QUERY PLAN
Group (cost=4502.72..4505.52 rows=173 width=4)
Group Key: out_device
-> Sort (cost=4502.72..4504.12 rows=559 width=4)
Sort Key: out_device
-> Seq Scan on tbl_punch (cost=0.00..4477.21 rows=559 width=4)
Filter: ((out_device IS NOT NULL) AND (user_id = 5064))