QUERY PLAN
GroupAggregate (cost=65.56..65.80 rows=11 width=12)
Group Key: parent_id
-> Sort (cost=65.56..65.60 rows=18 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..65.18 rows=18 width=4)
Filter: (parent_id = ANY ('{1565,1596,1641,1658,1647,1578,1577,1576,1566,1562,1561,1560,1559,1558,1557}'::integer[]))