QUERY PLAN
GroupAggregate (cost=51.02..51.15 rows=7 width=12)
Group Key: parent_id
-> Sort (cost=51.02..51.04 rows=8 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..50.90 rows=8 width=4)
Filter: (parent_id = ANY ('{1713,1712,1711,1620}'::integer[]))