Why should an IVFFlat index be created after loading representative data rather than on an empty table?

1. A Empty tables cannot be indexed
2. ✓ B IVFFlat derives cluster centroids from existing rows; an empty table yields degenerate clusters (correct answer)
3. C IVFFlat requires a primary key
4. D It would lock the table

Shortcut: IVFFlat partitions the vector space using k-means over existing rows. Built on an empty or unrepresentative table, the centroids are meaningless and recall collapses.