QUERY PLAN
GroupAggregate (cost=58.97..59.25 rows=13 width=12)
Group Key: parent_id
-> Sort (cost=58.97..59.02 rows=20 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..58.54 rows=20 width=4)
Filter: (parent_id = ANY ('{1686,1647,1687,1672,1669,1668,1667,1662,1661,1580}'::integer[]))