QUERY PLAN
GroupAggregate (cost=50.46..50.54 rows=4 width=12)
Group Key: parent_id
-> Sort (cost=50.46..50.47 rows=5 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..50.40 rows=5 width=4)
Filter: (parent_id = ANY ('{1596,1641,1631,1630,1629}'::integer[]))