Given the top 100 results produced by a flat index - how many of those are returned in the top 100 of our PQ/IVFPQ index. Although it's worth noting that this i

Given the top 100 results produced by a flat index - how many of those are returned in the top 100 of our PQ/IVFPQ index. Although it's worth noting that this is at the lower end of performance for PQ, using the same Sift1M dataset we can hit 76% with IVFPQ using nlist=256, m=32, and nbits=8. I'm sure this could be increased with a little more fine-tuning too. A couple of options: * IVFPQ seems reasonable but unlikely to hit 90% * HNSW could be a fast and accurate alternative * a Flat IVF index could definitely reach 90%, but it may be slow