Ann

• IVF Index

  Inverted File index; partitions high-dimensional vector space into Voronoi cells for scalable approximate nearest-neighbour search.

• HNSW

  Hierarchical Navigable Small World; state-of-the-art graph-based approximate nearest-neighbour index balancing speed and recall.

• FAISS

  Facebook AI Similarity Search; open-source library implementing multiple approximate nearest-neighbour indexes for efficient similarity search at scale.

• Approximate Nearest Neighbour

  Fast nearest-neighbour search algorithm sacrificing exactness for speed; enables practical dense retrieval at scale. Abbreviated ANN.