QUERY PLAN
GroupAggregate (cost=52.48..52.55 rows=4 width=12)
Group Key: parent_id
-> Sort (cost=52.48..52.49 rows=4 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.44 rows=4 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1813,1831,1834}'::integer[])))