Vector search

11 articles tagged “Vector search”.

A field guide to vector similarity measures

Dot product, cosine, Euclidean, Manhattan and Hamming - what each one actually measures, why most of them collapse into the same ranking once your vectors are normalised, and the handful of mistakes that bite in practice.

Asymmetric query quantization in DiskBBQ

Ben Trent and Thomas Veasey shipped another DiskBBQ optimisation today: quantising queries against coarser parent centroids instead of per-document ones. 5x off the quantisation stack with no meaningful recall loss. The insight underneath is that the query path and the document path don’t have to be treated symmetrically.

SMART: late interaction without retraining

A new paper out this week shows the per-token hidden states of off-the-shelf single-vector embedders already carry the information needed for ColBERT-style MaxSim - and you can wire it in at inference time, without retraining. The late-interaction deployment barrier I most underestimated just dropped.

Faster similar-document search in Elasticsearch 9.4

Elasticsearch 9.4 adds query_vector_builder.lookup - a tiny API addition that collapses a two-request vector search into one and runs better than 3x faster. A small change with a big impact, and a look at where that ratio actually comes from.

SID-1: Train the loop, keep the index

SID AI’s SID-1 is the first retrieval model trained end-to-end with RL. Some observations through a search-and-IR lens: the middle of the retrieval pipeline collapses into one trained model, the NDCG reward gets deliberately bent toward recall, and the agentic-retrieval loop becomes a subagent you hand to a larger system.

xAI algorithm through a search lens

xAI open-sourced the For You feed algorithm today. Three observations through a search-and-IR lens: two-tower’s quiet dominance, the retrieve/rank split surviving the bitter lesson, and recsys converging with search.

What to make of TurboQuant

A new quantisation method out of Google Research is making the rounds. Qdrant shipped it. Elastic ran the benchmarks and politely declined. Both responses tell you something useful.

The pattern goes all the way down

DiskBBQ’s new filtered-search optimisation is the same architectural move I wrote about last week, applied one layer deeper. The pattern is fractal - and that’s what makes it useful.

A primer on late interaction

How ColBERT-style token-level matching fits between single-vector dense retrieval and cross-encoders, why MaxSim is the clever bit, and what the storage tax actually looks like in practice.