Here are the steps to add 4 million embeddings to a Faiss index:
- Define the dimensionality of the embeddings (e.g. 512, 1024)
- Create an empty Faiss index of the desired type (e.g. IVF, Flat, HNSW) with the corresponding dimensionality
- Load the 4 million embeddings into memory. This will depend on how the embeddings are stored (e.g. in a file on disk, in a database, in memory).
- Convert the embeddings to a numpy array (if not already in numpy format).
- Normalize the embeddings to have unit length using L2 normalization. This will enable efficient cosine similarity calculations.
- Add the embeddings to the Faiss index using the add method. This should be done in batches for efficient memory usage.
- Save the Faiss index to disk if you want to reuse it later.
The time it takes to add 4 million embeddings to a Faiss index will depend on the type of index, dimensionality of the embeddings, and hardware resources available. It is recommended to use a GPU for faster indexing.