elasticsearch/docs/reference/release-notes/highlights.asciidoc

[[release-highlights]]
== What's new in {minor-version}

coming::[{minor-version}]

Here are the highlights of what's new and improved in {es} {minor-version}!
ifeval::[\{release-state}\"!=\"unreleased\"]
For detailed information about this release, see the <<es-release-notes>> and
<<breaking-changes>>.
endif::[]

// Add previous release to the list
Other versions:

{ref-bare}/8.7/release-highlights.html[8.7]
| {ref-bare}/8.6/release-highlights.html[8.6]
| {ref-bare}/8.5/release-highlights.html[8.5]
| {ref-bare}/8.4/release-highlights.html[8.4]
| {ref-bare}/8.3/release-highlights.html[8.3]
| {ref-bare}/8.2/release-highlights.html[8.2]
| {ref-bare}/8.1/release-highlights.html[8.1]
| {ref-bare}/8.0/release-highlights.html[8.0]

// tag::notable-highlights[]

[discrete]
[[add_new_similarity_field_to_knn_clause_in_search]]
=== Add new `similarity` field to `knn` clause in `_search`
This adds a new parameter to `knn` that allows filtering nearest
neighbor results that are outside a given similarity.

`num_candidates` and `k` are still required as this controls the
nearest-neighbor vector search accuracy and exploration. For each shard
the query will search `num_candidates` and only keep those that are
within the provided `similarity` boundary, and then finally reduce to
only the global top `k` as normal.

For example, when using the `l2_norm` indexed similarity value, this
could be considered a `radius` post-filter on `knn`.

relates to: https://github.com/elastic/elasticsearch/issues/84929 &&
https://github.com/elastic/elasticsearch/pull/93574

{es-pull}94828[#94828]

// end::notable-highlights[]