QUERY PLAN
GroupAggregate (cost=54.02..54.19 rows=9 width=12)
Group Key: parent_id
-> Sort (cost=54.02..54.05 rows=10 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..53.86 rows=10 width=4)
Filter: (parent_id = ANY ('{1596,1734,1750,1747,1746,1727}'::integer[]))