QUERY PLAN
GroupAggregate (cost=59.03..59.26 rows=12 width=12)
Group Key: parent_id
-> Sort (cost=59.03..59.06 rows=15 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..58.73 rows=15 width=4)
Filter: (parent_id = ANY ('{1347,1349,1356,1358,1596,1734,1823,1824,1830}'::integer[]))