QUERY PLAN
GroupAggregate (cost=54.65..54.75 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=54.65..54.67 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..54.58 rows=6 width=4)
Filter: (parent_id = ANY ('{1727,1724,1726,1725,1720,1719}'::integer[]))