QUERY PLAN
GroupAggregate (cost=52.62..52.77 rows=8 width=12)
Group Key: parent_id
-> Sort (cost=52.62..52.64 rows=9 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..52.48 rows=9 width=4)
Filter: (parent_id = ANY ('{1731,1713,1712,1711,1620}'::integer[]))