ACORN Bridges Broken HNSW Graphs to Keep Filtered Vector Search Fast
Metadata filters can split Qdrant’s HNSW graph into isolated islands, killing search speed. In a benchmark on a million‑vector collection, ACORN‑1’s runtime neighbor‑of‑neighbor expansion reclaimed connectivity with negligible build cost, outperforming filter‑able HNSW’s expensive index‑time edges and full scans for selective filters.