QUERY PLAN
GroupAggregate (cost=49.34..49.41 rows=4 width=12)
Group Key: parent_id
-> Sort (cost=49.34..49.35 rows=4 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..49.30 rows=4 width=4)
Filter: (parent_id = ANY ('{1535,1667,1822}'::integer[]))