QUERY PLAN
GroupAggregate (cost=49.45..49.58 rows=7 width=12)
Group Key: parent_id
-> Sort (cost=49.45..49.47 rows=8 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..49.33 rows=8 width=4)
Filter: (parent_id = ANY ('{1596,1734,1727}'::integer[]))