QUERY PLAN
GroupAggregate (cost=58.73..58.90 rows=9 width=12)
Group Key: parent_id
-> Sort (cost=58.73..58.76 rows=11 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..58.54 rows=11 width=4)
Filter: (parent_id = ANY ('{1535,1547,1546,1543,1548,1544,1549,1565,1596,1641}'::integer[]))