QUERY PLAN
GroupAggregate (cost=45.93..45.97 rows=2 width=12)
Group Key: parent_id
-> Sort (cost=45.93..45.94 rows=2 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..45.92 rows=2 width=4)
Filter: (parent_id = ANY ('{1609,1611}'::integer[]))