QUERY PLAN
GroupAggregate (cost=57.94..58.11 rows=8 width=12)
Group Key: parent_id
-> Sort (cost=57.94..57.97 rows=11 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..57.75 rows=11 width=4)
Filter: (parent_id = ANY ('{1535,1547,1546,1543,1548,1544,1549,1565,1596,1641}'::integer[]))