QUERY PLAN
GroupAggregate (cost=52.74..52.97 rows=11 width=12)
Group Key: parent_id
-> Sort (cost=52.74..52.78 rows=16 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.42 rows=16 width=4)
Filter: (parent_id = ANY ('{1596,1641,1647,1697,1696,1687}'::integer[]))