QUERY PLAN
GroupAggregate (cost=49.55..49.65 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=49.55..49.57 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..49.48 rows=6 width=4)
Filter: (parent_id = ANY ('{1596,1687,1696}'::integer[]))