But there is another scenario that we need small scan is that, we do not know the stop row but we only want a small set of results. For example, in the implementation of region locator, we will use small scan and set caching to 1 as we only need one row.
So I think we need to add a new option(maybe called limit?) for the scan object, and deprecate the small option. And the server side modification should also be committed to branch-1 to simplify the logic of async client in 2.0.