QUERY PLAN
GroupAggregate (cost=60.35..111.42 rows=6 width=12)
Group Key: remain_task.task_group_id
-> Hash Anti Join (cost=60.35..111.33 rows=6 width=4)
Hash Cond: (remain_task.id = child_task.parent_id)
-> Seq Scan on tbl_tasks remain_task (cost=0.00..50.90 rows=6 width=8)
Filter: ((status <> 1) AND (task_group_id = 106))
-> Hash (cost=44.60..44.60 rows=1260 width=4)
-> Seq Scan on tbl_tasks child_task (cost=0.00..44.60 rows=1260 width=4)