This is true only when you have relatively steady flows, or infinite multiprocessing. In that case, yes, the queue is in practise either "almost empty" or "infi

This is true only when you have relatively steady flows, or infinite multiprocessing. In that case, yes, the queue is in practise either "almost empty" or "infinite". I think the reason you get the responses you do is people are used to systems with high variation in flow rates that can only process a limited number of items at the same time, and for these, queues can soak up a lot of variability by growing long and then being worked off quickly again.