QUERY PLAN
GroupAggregate (cost=49.50..49.55 rows=3 width=12)
Group Key: parent_id
-> Sort (cost=49.50..49.51 rows=3 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..49.48 rows=3 width=4)
Filter: (parent_id = ANY ('{1712,1711,1620}'::integer[]))