0-4-6-understand-ivf-index

name	0.4.6-understand-ivf_index
description	[0.4.6] Inverted File Index; clusters vectors into Voronoi cells via k-means; search prunes to nearest centroids then

understand-ivf_index

CALL NUMBER: vector_databases_and_embeddings.ivf_index DEFINITION: Inverted File Index; clusters vectors into Voronoi cells via k-means; search prunes to nearest centroids then scans partitions.

Invoke this skill to understand ivf_index down to its primitives. The RELATIVE ROOT below is the least-fixed-point closure of everything it bundles from — the full import cone, grouped by the lib each prim comes from. Projected from a prover-typed KB (MAP/SWI-Prolog consistency gate): every reference below resolves.

THE RELATIVE ROOT (the import cone, by lib)

from vector_databases_and_embeddings

• indexing_strategy (d1): Choice and configuration of ANN algorithm (HNSW, IVF, ANNOY, LSH) and its parameters (ef, nlist, nprobe) governing recall/speed trade-off.
• product_quantization (d1): A vector quantization technique that splits a high-dimensional vector into subvectors, independently quantizes each subvector, and concatenates codes to form a compact representation.
• memory_footprint (d2): RAM or VRAM required to hold index and vectors; quantization (PQ, int8) is the primary compression lever.

CONSUMERS (what needs this)

approximate_nearest_neighbor, idx_algorithm_selection, idx_hybrid_composition, idx_ivf_params

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Projected from the vector databases and embeddings KB (262 concepts / 150 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.

(leaf — this is an actual skill.)