QUERY PLAN
GroupAggregate (cost=149.80..149.82 rows=1 width=12)
Group Key: task_group_id
-> Sort (cost=149.80..149.80 rows=1 width=4)
Sort Key: task_group_id
-> Seq Scan on tbl_tasks (cost=0.00..149.79 rows=1 width=4)
Filter: ((parent_id IS NULL) AND (task_group_id = ANY ('{196,86}'::integer[])) AND (status = 0))