cvx_index::hnsw

Module temporal_lsh

Source
Expand description

Temporal Locality-Sensitive Hashing (T-LSH) — RFC-008 Phase 2.

An auxiliary index for composite spatiotemporal queries (α < 1.0). Instead of over-fetching from the semantic HNSW and re-ranking, T-LSH generates candidates that are naturally distributed in both semantic and temporal space.

§Hash function

For a point (vector, timestamp):

h_ST(v, t) = h_sem(v) ⊕ h_time(t)

h_sem(v) = [sign(r₁·v), sign(r₂·v), ..., sign(rₖ·v)]  (random hyperplane LSH)
h_time(t) = floor(t / bucket_size)                       (temporal bucketing)

Combined: concatenate semantic_bits + temporal_bits into a u64 hash

§References

  • Indyk & Motwani (1998). Approximate nearest neighbors. STOC.
  • Lv et al. (2007). Multi-probe LSH. VLDB.

Structs§

TLSHConfig
Configuration for the T-LSH index.
TemporalLSH
Temporal Locality-Sensitive Hashing index.