Android：标签中的视图堆栈管理？

I see some answers here prefer views over activities as contents of tabs. Correct me if I am wrong. My understanding is that by switching out views, it's possible to keep the navigation flow inside a tab (more user friendly, I think). But I wonder how to manage the view stack then in case of the back button events. Also this could cause one giant Activity with large amount of views, which might not be good. I see some answers here prefer views over activ