From d7d0c6d4543f2ecb9f2aa583bdb059271146bb5f Mon Sep 17 00:00:00 2001
From: shainaraskas <58563081+shainaraskas@users.noreply.github.com>
Date: Fri, 25 Jul 2025 09:55:54 -0700
Subject: [PATCH] add availability to oversample value of 0 (#131707)

(cherry picked from commit 4dd124b4db781c92eab6610bdf2b4d97cb84e30b)
---
 .../elasticsearch/mapping-reference/dense-vector.md          | 5 ++++-
 .../query-languages/query-dsl/query-dsl-knn-query.md         | 4 +++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/docs/reference/elasticsearch/mapping-reference/dense-vector.md b/docs/reference/elasticsearch/mapping-reference/dense-vector.md
index 7f3a701bde3f8..3d9f2f1a10540 100644
--- a/docs/reference/elasticsearch/mapping-reference/dense-vector.md
+++ b/docs/reference/elasticsearch/mapping-reference/dense-vector.md
@@ -277,7 +277,10 @@ $$$dense-vector-index-options$$$
 :   (Optional, object) An optional section that configures automatic vector rescoring on knn queries for the given field. Only applicable to quantized index types.
 :::::{dropdown} Properties of rescore_vector
 `oversample`
-:   (required, float) The amount to oversample the search results by. This value should be greater than `1.0` and less than `10.0` or exactly `0` to indicate no oversampling & rescoring should occur. The higher the value, the more vectors will be gathered and rescored with the raw values per shard.
+:   (required, float) The amount to oversample the search results by. This value should be one of the following: 
+    * Greater than `1.0` and less than `10.0` 
+    * Exactly `0` to indicate no oversampling and rescoring should occur {applies_to}`stack: ga 9.1`
+    :   The higher the value, the more vectors will be gathered and rescored with the raw values per shard.
     :   In case a knn query specifies a `rescore_vector` parameter, the query `rescore_vector` parameter will be used instead.
     :   See [oversampling and rescoring quantized vectors](docs-content://solutions/search/vector/knn.md#dense-vector-knn-search-rescoring) for details.
 :::::
diff --git a/docs/reference/query-languages/query-dsl/query-dsl-knn-query.md b/docs/reference/query-languages/query-dsl/query-dsl-knn-query.md
index ab2dd232eaf50..9769997986ba5 100644
--- a/docs/reference/query-languages/query-dsl/query-dsl-knn-query.md
+++ b/docs/reference/query-languages/query-dsl/query-dsl-knn-query.md
@@ -113,7 +113,9 @@ Rescoring only makes sense for quantized vectors; when [quantization](/reference
     * Retrieve `num_candidates` candidates per shard.
     * From these candidates, the top `k * oversample` candidates per shard will be rescored using the original vectors.
     * The top `k` rescored candidates will be returned.
-    Must be >= 1f to indicate oversample factor, or exactly `0` to indicate that no oversampling and rescoring should occur.
+    Must be one of the following values: 
+      * \>= 1f to indicate the oversample factor
+      * Exactly `0` to indicate that no oversampling and rescoring should occur. {applies_to}`stack: ga 9.1`
 
 
 See [oversampling and rescoring quantized vectors](docs-content://solutions/search/vector/knn.md#dense-vector-knn-search-rescoring) for details.