Quantization transforms floating-point vector values into lower-precision discrete integers. Scaling and rounding can reduce memory use and let indexes compare integers faster than floating-point ranges. section 10.3.6
A NumPy experiment
Scale a float vector, cast it to an integer type, average integer values, and scale back. The example demonstrates how carefully chosen scaling can preserve values, while more aggressive quantization can introduce distortion or overflow-like artifacts.
For high-dimensional semantic search, product quantization splits a vector into smaller subvectors and quantizes each with clustering. IVFPQ in Faiss and HNSW plus product quantization support web-scale approximate nearest-neighbor indexing. section 10.3.6












