get_optimal_index_keys_v2 support faiss AutoTune about autofaiss HOT 4 OPEN

Autofaiss is an alternative implementation of faiss AutoTune that works based on the contraints listed in the readme.
Do you have any specific suggestions?

from autofaiss.

I think the faiss readme is a recommendation rather than a standard, it's a tradeoff between performance and recall.
Examples:
http://ann-benchmarks.com/sift-128-euclidean_10_euclidean.html

but autofaiss

I recommend randomly sampling the embeddings and evaluate recall/perf by various index key parameters to get optimal index key，such as https://github.com/erikbern/ann-benchmarks/blob/8807d6ead4cf14318ac43166cdabf02b491f620e/algos.yaml#L146-L187

from autofaiss.

from autofaiss.

Hello @xiongqiangcs !

We chose to use a heuristic rather than benchmarking n different indices because it is n times faster and that the heuristic is not too far from finding the best index.
Also, the fine-tuning step makes it possible to improve the final index performance, so we close the gap with an eventually better index key to use.

But indeed, benchmarking n index keys could give better results. There might be good ideas to use to make it possible to benchmark quickly several indices while not taking too much time! We are open to any suggestions if you want to try it out 😁

from autofaiss.