[VoVAllen]

Hi, I'm the author of the article. In our product, VectorChord, we use a quantization algorithm called RaBitQ, which doesn’t require a separate codebook. Unlike IVFPQ, it avoids the need to maintain and update the corresponding codebook, so the update issue you mentioned is not a problem. Regarding filtering, I’m not sure which specific scenario you’re referring to, but we currently support iterative post-filtering and are technically capable of perfectly supporting pre-filtering as well.

[binarymax]

Pre and post filtering are both not great. Some HNSW implementations in products like Vespa and Qdrant have filter-during-search.

This remains an unsolved problem in cluster-based indices.