QUERY PLAN
GroupAggregate (cost=47.90..47.93 rows=2 width=12)
Group Key: parent_id
-> Sort (cost=47.90..47.90 rows=2 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..47.89 rows=2 width=4)
Filter: (parent_id = ANY ('{1653,1654}'::integer[]))