QUERY PLAN
GroupAggregate (cost=53.51..53.64 rows=7 width=12)
Group Key: parent_id
-> Sort (cost=53.51..53.53 rows=8 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..53.39 rows=8 width=4)
Filter: (parent_id = ANY ('{1584,1596,1644,1641,1631,1630,1629}'::integer[]))