QUERY PLAN
GroupAggregate (cost=60.27..60.43 rows=9 width=12)
Group Key: parent_id
-> Sort (cost=60.27..60.29 rows=10 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..60.10 rows=10 width=4)
Filter: (parent_id = ANY ('{42,48,52,53,54,55,56,57,58,59}'::integer[]))