QUERY PLAN
GroupAggregate (cost=47.55..47.63 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=47.55..47.56 rows=5 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..47.49 rows=5 width=4)
Filter: (parent_id = ANY ('{1713,1791}'::integer[]))