QUERY PLAN
GroupAggregate (cost=54.43..54.69 rows=13 width=12)
Group Key: parent_id
-> Sort (cost=54.43..54.47 rows=18 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..54.05 rows=18 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1596,1647,1734,1727}'::integer[])))