QUERY PLAN
GroupAggregate (cost=48.88..48.94 rows=4 width=12)
Group Key: parent_id
-> Sort (cost=48.88..48.88 rows=4 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..48.84 rows=4 width=4)
Filter: (parent_id = ANY ('{1667,1666,1664,1658}'::integer[]))