QUERY PLAN
GroupAggregate (cost=149.80..149.83 rows=2 width=12)
Group Key: parent_id
-> Sort (cost=149.80..149.80 rows=2 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..149.79 rows=2 width=4)
Filter: ((parent_id = ANY ('{1601,1602}'::integer[])) AND (status = 1))