QUERY PLAN
GroupAggregate (cost=47.83..47.92 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=47.83..47.84 rows=6 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..47.75 rows=6 width=4)
Filter: (parent_id = ANY ('{1713,1731}'::integer[]))