QUERY PLAN
GroupAggregate (cost=60.77..61.08 rows=16 width=12)
Group Key: parent_id
-> Sort (cost=60.77..60.82 rows=21 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..60.30 rows=21 width=4)
Filter: (parent_id = ANY ('{1684,1683,1671,1670,1647,1641,1564,1563,1508,1507}'::integer[]))