QUERY PLAN
GroupAggregate (cost=52.95..53.05 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=52.95..52.97 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.88 rows=6 width=4)
Filter: (parent_id = ANY ('{1727,1724,1726,1725,1720,1719}'::integer[]))