QUERY PLAN
GroupAggregate (cost=55.35..55.48 rows=7 width=12)
Group Key: parent_id
-> Sort (cost=55.35..55.37 rows=8 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..55.23 rows=8 width=4)
Filter: (parent_id = ANY ('{1576,1577,1578,1596,1668,1686,1734}'::integer[]))