Elasticsearch 9.1 makes BBQ default for dense vectors of 384+ dims, adds ACORN-1
Elasticsearch 9.1 adopted BBQ quantization as the default for dense vectors with 384 or more dimensions, and introduced ACORN-1 filtering
Why it matters
The point at which quantized indexes moved from an option to the default
Source — Primary sources first; secondary reports are labelled “Press”
Officialelastic.cohttps://www.elastic.co/search-labs/blog/elasticsearch-9-1-bbq-acorn-vector-searchAdded in Week 35, 2026 · See that week