QUERY PLAN
GroupAggregate (cost=60.52..60.71 rows=10 width=12)
Group Key: parent_id
-> Sort (cost=60.52..60.55 rows=12 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..60.30 rows=12 width=4)
Filter: (parent_id = ANY ('{1596,1578,1577,1576,1566,1565,1564,1563,1562,1561}'::integer[]))