问题
Does FirebaseRecyclerAdapter load all children at a reference at once, or only upon scrolling. Suppose we have a ref containing thousands of chat messages, are they all going to be fetched from database at once??
回答1:
The FirebaseRecyclerAdapter loads whatever child nodes are matches by the DatabaseReference or Query you pass into it. It does not implement pagination or another form of load-on-demand.
来源：https://stackoverflow.com/questions/43608616/firebaserecycleradapter-data-fetching-policy