QUERY PLAN
GroupAggregate (cost=52.64..52.82 rows=9 width=12)
Group Key: parent_id
-> Sort (cost=52.64..52.67 rows=12 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.42 rows=12 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1596,1641,1647,1658}'::integer[])))