Function create_embeddings_index 

pub fn create_embeddings_index(model: &ModelName) -> String

The DiskANN index over a model’s vectors.

Load-bearing for correctness, not only for speed. Measured against libSQL 0.9.30: a blob of the wrong length inserted into an F32_BLOB(4) column is accepted while no vector index exists, and rejected — with the row not landing — once one does. §4.1 previously claimed the column type enforced its own dimension at insert time; it does not. So this index is created together with the table it indexes and is never optional, and dropping it to speed up a bulk load would silently disarm the only storage-layer check on dimension.