Let's suppose we have two topics, one with 20 partitions and another with 1 partition. If we set parallelism.default to 10, I understand that it will create 10 subtasks in total for each source. In the case of the topic with 20 partitions, it will work correctly, but for the topic with only one partition, 10 subtasks will be created, and 9 of them will be idle. Do these 9 subtasks have resources allocated to them and consume resources even though they are idle, or do they not consume any resources from the TaskManagers when idle?
I understand that CPU consumption will be minimal, but I'm not sure how much memory each of these 9 subtasks will reserve. Additionally, they will indeed occupy space in the available slots.
