QUERY PLAN
GroupAggregate (cost=161.79..161.92 rows=6 width=12)
Group Key: parent_id
-> Sort (cost=161.79..161.82 rows=9 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..161.65 rows=9 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1598,1600,1603,1592,1595,1566,1583,1591,1568,1562}'::integer[])))