You need the prefix because without it, you will end up picking the same object every time you run the algorithm (e.g. On the next day's stream of data) Depend

You need the prefix because without it, you will end up picking the same object every time you run the algorithm (e.g. On the next day's stream of data) Depends, of course, upon the size of the stream and the range in variety of the objects in the stream.A stream of bytes would not be a good use case, for example.