QUERY PLAN
GroupAggregate (cost=54.09..54.20 rows=6 width=12)
Group Key: parent_id
-> Sort (cost=54.09..54.11 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..54.02 rows=6 width=4)
Filter: ((status = 1) AND (parent_id = ANY ('{1596,1734,1768,1769}'::integer[])))