QUERY PLAN
GroupAggregate (cost=50.85..50.99 rows=7 width=12)
Group Key: parent_id
-> Sort (cost=50.85..50.88 rows=8 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..50.73 rows=8 width=4)
Filter: (parent_id = ANY ('{1596,1734,1768,1776}'::integer[]))