QUERY PLAN
GroupAggregate (cost=49.36..49.44 rows=5 width=12)
Group Key: parent_id
-> Sort (cost=49.36..49.37 rows=5 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..49.30 rows=5 width=4)
Filter: (parent_id = ANY ('{1813,1834,1837}'::integer[]))