Builds the index using the specified training configuration. Required before efficient querying.
Prior to calling this, all queries will be conducted using encrypted exhaustive search.
After, they will be conducted using encrypted ANN search.
(Optional) Training parameters including n_lists, batch size, max iterations, tolerance, and max memory.
There must be at least 2 * n_lists or 10,000 (whichever is greater) vector embeddings in the index prior to calling this function. The n_lists parameter is configured within the TrainingConfig object.