QUERY PLAN
GroupAggregate (cost=55.56..55.65 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=55.56..55.57 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..55.48 rows=6 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1535,1672,1669,1667,1662,1661}'::integer[])))