QUERY PLAN
GroupAggregate (cost=174.43..174.67 rows=9 width=12)
Group Key: parent_id
-> Sort (cost=174.43..174.48 rows=20 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..174.00 rows=20 width=4)
Filter: (parent_id = ANY ('{878,818,795,862,924,877,975,886,853,808,884,883,882,881,812,807,810,805,811,802}'::integer[]))