# Set verbosity level
        if faiss_verbose is not None:
            self.faiss_index.verbose = faiss_verbose
            if hasattr(self.faiss_index, "index") and self.faiss_index.index is not None:
                self.faiss_index.index.verbose = faiss_verbose
            if hasattr(self.faiss_index, "quantizer") and self.faiss_index.quantizer is not None:
                self.faiss_index.quantizer.verbose = faiss_verbose
            if hasattr(self.faiss_index, "clustering_index") and self.faiss_index.clustering_index is not None:
                self.faiss_index.clustering_index.verbose = faiss_verbose

        # Train
        if train_size is not None:
            train_vecs = vectors[:train_size] if column is None else vectors[:train_size][column]
            logger.info(f"Training the index with the first {len(train_vecs)} vectors")
            self.faiss_index.train(train_vecs)
        else:
            logger.info("Ignored the training step of the faiss index as `train_size` is None.")