QUERY PLAN
GroupAggregate (cost=52.71..52.80 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=52.71..52.72 rows=5 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.65 rows=5 width=4)
Filter: (parent_id = ANY ('{1700,1708,1703,1698,1620}'::integer[]))