I understand the reduction of memory using binary vectors. However, if you use the normal vectors for knn re-ranking, you still need the complete vectors for all items, right? That sounds like you need even more memory. Can you elaborate on that?
Thanks for the question. You need to store the full-precision vector data, but you can build the index with binary vectors. The memory usage of the index can be reduced. Data and index, are two different things that need storage.