QUERY PLAN
GroupAggregate (cost=52.97..53.21 rows=12 width=12)
Group Key: parent_id
-> Sort (cost=52.97..53.01 rows=16 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.65 rows=16 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1596,1647,1720}'::integer[])))