QUERY PLAN
GroupAggregate (cost=47.85..48.06 rows=11 width=12)
Group Key: parent_id
-> Sort (cost=47.85..47.89 rows=13 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..47.61 rows=13 width=4)
Filter: (parent_id = ANY ('{1713,1791}'::integer[]))