[8.19] Make dense_vector fields updatable to bbq_flat/bbq_hnsw (#128291) (#129495)

docs/changelog/128291.yaml

@@ -0,0 +1,5 @@
+pr: 128291
+summary: Make `dense_vector` fields updatable to bbq_flat/bbq_hnsw
+area: Vector Search
+type: enhancement
+issues: []

docs/reference/mapping/types/dense-vector.asciidoc

@@ -476,10 +476,10 @@ To better accommodate scaling and performance needs, updating the `type` setting
 
 [source,txt]
 ----
-flat --> int8_flat --> int4_flat --> hnsw --> int8_hnsw --> int4_hnsw
+flat --> int8_flat --> int4_flat --> bbq_flat --> hnsw --> int8_hnsw --> int4_hnsw --> bbq_hnsw
 ----
 
-For updating all HNSW types (`hnsw`, `int8_hnsw`, `int4_hnsw`) the number of connections `m` must either stay the same or increase. For scalar quantized formats  (`int8_flat`, `int4_flat`, `int8_hnsw`, `int4_hnsw`) the `confidence_interval` must always be consistent (once defined, it cannot change).
+For updating all HNSW types (`hnsw`, `int8_hnsw`, `int4_hnsw`, `bbq_hnsw`) the number of connections `m` must either stay the same or increase. For the scalar quantized formats  `int8_flat`, `int4_flat`, `int8_hnsw` and `int4_hnsw` the `confidence_interval` must always be consistent (once defined, it cannot change).
 
 Updating `type` in `index_options` will fail in all other scenarios.
 

qa/rolling-upgrade/src/javaRestTest/java/org/elasticsearch/upgrades/DenseVectorMappingUpdateIT.java

@@ -15,6 +15,8 @@ import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.index.IndexVersion;
+import org.elasticsearch.index.IndexVersions;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xcontent.XContentType;
 
@@ -31,6 +33,8 @@ import static org.elasticsearch.rest.action.search.RestSearchAction.TOTAL_HITS_A
  */
 public class DenseVectorMappingUpdateIT extends AbstractRollingUpgradeTestCase {
 
+    private static final String SYNTHETIC_SOURCE_FEATURE = "gte_v8.12.0";
+
     private static final String BULK1 = """
                     {"index": {"_id": "1"}}
                     {"embedding": [1, 1, 1, 1]}
@@ -86,10 +90,23 @@ public class DenseVectorMappingUpdateIT extends AbstractRollingUpgradeTestCase {
             String indexName = "test_index";
             if (isOldCluster()) {
                 Request createIndex = new Request("PUT", "/" + indexName);
-                XContentBuilder mappings = XContentBuilder.builder(XContentType.JSON.xContent())
-                    .startObject()
-                    .startObject("mappings")
-                    .startObject("properties")
+                boolean useSyntheticSource = randomBoolean() && oldClusterHasFeature(SYNTHETIC_SOURCE_FEATURE);
+
+                IndexVersion version = getOldClusterIndexVersion();
+                boolean useIndexSetting = version.onOrAfter(IndexVersions.DEPRECATE_SOURCE_MODE_MAPPER);
+                XContentBuilder payload = XContentBuilder.builder(XContentType.JSON.xContent()).startObject();
+                if (useSyntheticSource) {
+                    if (useIndexSetting) {
+                        payload.startObject("settings").field("index.mapping.source.mode", "synthetic").endObject();
+                    }
+                }
+                payload.startObject("mappings");
+                if (useIndexSetting == false) {
+                    payload.startObject("_source");
+                    payload.field("mode", "synthetic");
+                    payload.endObject();
+                }
+                payload.startObject("properties")
                     .startObject("embedding")
                     .field("type", "dense_vector")
                     .field("index", "true")
@@ -104,7 +121,7 @@ public class DenseVectorMappingUpdateIT extends AbstractRollingUpgradeTestCase {
                     .endObject()
                     .endObject()
                     .endObject();
-                createIndex.setJsonEntity(Strings.toString(mappings));
+                createIndex.setJsonEntity(Strings.toString(payload));
                 client().performRequest(createIndex);
                 Request index = new Request("POST", "/" + indexName + "/_bulk/");
                 index.addParameter("refresh", "true");

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.vectors/180_update_dense_vector_type.yml

@@ -2116,3 +2116,394 @@ setup:
   - contains: {hits.hits: {_id: "2"}}
   - contains: {hits.hits: {_id: "21"}}
   - contains: {hits.hits: {_id: "31"}}
+
+---
+"Test update flat --> bbq_flat --> bbq_hnsw":
+  - requires:
+      capabilities:
+        - method: POST
+          path: /_search
+          capabilities: [ optimized_scalar_quantization_bbq ]
+      test_runner_features: capabilities
+      reason: "BBQ is required to test upgrading to bbq_flat and bbq_hnsw"
+  - requires:
+      reason: 'dense_vector updatable to bbq capability required'
+      test_runner_features: [ capabilities ]
+      capabilities:
+        - method: PUT
+          path : /_mapping
+          capabilities: [ dense_vector_updatable_bbq ]
+  - do:
+      indices.create:
+        index: vectors_64
+        body:
+          settings:
+            index:
+              number_of_shards: 1
+          mappings:
+            properties:
+              vector:
+                type: dense_vector
+                dims: 64
+                index: true
+                similarity: max_inner_product
+                index_options:
+                  type: flat
+
+  - do:
+      index:
+        index: vectors_64
+        id: "1"
+        body:
+          vector: [0.077,  0.32 , -0.205,  0.63 ,  0.032,  0.201,  0.167, -0.313,
+                   0.176,  0.531, -0.375,  0.334, -0.046,  0.078, -0.349,  0.272,
+                   0.307, -0.083,  0.504,  0.255, -0.404,  0.289, -0.226, -0.132,
+                   -0.216,  0.49 ,  0.039,  0.507, -0.307,  0.107,  0.09 , -0.265,
+                   -0.285,  0.336, -0.272,  0.369, -0.282,  0.086, -0.132,  0.475,
+                   -0.224,  0.203,  0.439,  0.064,  0.246, -0.396,  0.297,  0.242,
+                   -0.028,  0.321, -0.022, -0.009, -0.001  ,  0.031, -0.533,  0.45,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+  - do:
+      indices.put_mapping:
+        index: vectors_64
+        body:
+          properties:
+            embedding:
+              type: dense_vector
+              dims: 64
+              index_options:
+                type: bbq_flat
+
+  - do:
+      indices.get_mapping:
+        index: vectors_64
+
+  - match: { vectors_64.mappings.properties.embedding.type: dense_vector }
+  - match: { vectors_64.mappings.properties.embedding.index_options.type: bbq_flat }
+
+  - do:
+      index:
+        index: vectors_64
+        id: "2"
+        body:
+          vector: [0.196,  0.514,  0.039,  0.555, -0.042,  0.242,  0.463, -0.348,
+                   -0.08 ,  0.442, -0.067, -0.05 , -0.001,  0.298, -0.377,  0.048,
+                   0.307,  0.159,  0.278,  0.119, -0.057,  0.333, -0.289, -0.438,
+                   -0.014,  0.361, -0.169,  0.292, -0.229,  0.123,  0.031, -0.138,
+                   -0.139,  0.315, -0.216,  0.322, -0.445, -0.059,  0.071,  0.429,
+                   -0.602, -0.142,  0.11 ,  0.192,  0.259, -0.241,  0.181, -0.166,
+                   0.082,  0.107, -0.05 ,  0.155,  0.011,  0.161, -0.486,  0.569,
+                   -0.489,  0.901,  0.208,  0.011, -0.209, -0.153, -0.27 , -0.013]
+  - do:
+      indices.flush:
+        index: vectors_64
+  - do:
+      indices.put_mapping:
+        index: vectors_64
+        body:
+          properties:
+            embedding:
+              type: dense_vector
+              dims: 64
+              index_options:
+                type: bbq_hnsw
+
+  - do:
+      indices.get_mapping:
+        index: vectors_64
+
+  - match: { vectors_64.mappings.properties.embedding.type: dense_vector }
+  - match: { vectors_64.mappings.properties.embedding.index_options.type: bbq_hnsw }
+
+  - do:
+      index:
+        index: vectors_64
+        id: "3"
+        body:
+          name: rabbit.jpg
+          vector: [0.139,  0.178, -0.117,  0.399,  0.014, -0.139,  0.347, -0.33 ,
+                   0.139,  0.34 , -0.052, -0.052, -0.249,  0.327, -0.288,  0.049,
+                   0.464,  0.338,  0.516,  0.247, -0.104,  0.259, -0.209, -0.246,
+                   -0.11 ,  0.323,  0.091,  0.442, -0.254,  0.195, -0.109, -0.058,
+                   -0.279,  0.402, -0.107,  0.308, -0.273,  0.019,  0.082,  0.399,
+                   -0.658, -0.03 ,  0.276,  0.041,  0.187, -0.331,  0.165,  0.017,
+                   0.171, -0.203, -0.198,  0.115, -0.007,  0.337, -0.444,  0.615,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+
+  - do:
+      indices.forcemerge:
+        index: vectors_64
+        max_num_segments: 1
+
+  - do:
+      indices.refresh: { }
+  - do:
+      search:
+        index: vectors_64
+        body:
+          knn:
+            field: vector
+            query_vector: [ 0.128,  0.067, -0.08 ,  0.395, -0.11 , -0.259,  0.473, -0.393,
+                            0.292,  0.571, -0.491,  0.444, -0.288,  0.198, -0.343,  0.015,
+                            0.232,  0.088,  0.228,  0.151, -0.136,  0.236, -0.273, -0.259,
+                            -0.217,  0.359, -0.207,  0.352, -0.142,  0.192, -0.061, -0.17 ,
+                            -0.343,  0.189, -0.221,  0.32 , -0.301, -0.1  ,  0.005,  0.232,
+                            -0.344,  0.136,  0.252,  0.157, -0.13 , -0.244,  0.193, -0.034,
+                            -0.12 , -0.193, -0.102,  0.252, -0.185, -0.167, -0.575,  0.582,
+                            -0.426,  0.983,  0.212,  0.204,  0.03 , -0.276, -0.425, -0.158 ]
+            k: 3
+            num_candidates: 3
+
+  - match: { hits.hits.0._id: "1" }
+  - match: { hits.hits.1._id: "3" }
+  - match: { hits.hits.2._id: "2" }
+---
+"Test update int8_hnsw --> bbq_flat":
+  - requires:
+      capabilities:
+        - method: POST
+          path: /_search
+          capabilities: [ optimized_scalar_quantization_bbq ]
+      test_runner_features: capabilities
+      reason: "BBQ is required to test upgrading to bbq_flat and bbq_hnsw"
+  - requires:
+      reason: 'dense_vector updatable to bbq capability required'
+      test_runner_features: [ capabilities ]
+      capabilities:
+        - method: PUT
+          path : /_mapping
+          capabilities: [ dense_vector_updatable_bbq ]
+  - do:
+      indices.create:
+        index: vectors_64
+        body:
+          settings:
+            index:
+              number_of_shards: 1
+          mappings:
+            properties:
+              vector:
+                type: dense_vector
+                dims: 64
+                index: true
+                similarity: max_inner_product
+                index_options:
+                  type: int8_hnsw
+
+  - do:
+      index:
+        index: vectors_64
+        id: "1"
+        body:
+          vector: [0.077,  0.32 , -0.205,  0.63 ,  0.032,  0.201,  0.167, -0.313,
+                   0.176,  0.531, -0.375,  0.334, -0.046,  0.078, -0.349,  0.272,
+                   0.307, -0.083,  0.504,  0.255, -0.404,  0.289, -0.226, -0.132,
+                   -0.216,  0.49 ,  0.039,  0.507, -0.307,  0.107,  0.09 , -0.265,
+                   -0.285,  0.336, -0.272,  0.369, -0.282,  0.086, -0.132,  0.475,
+                   -0.224,  0.203,  0.439,  0.064,  0.246, -0.396,  0.297,  0.242,
+                   -0.028,  0.321, -0.022, -0.009, -0.001  ,  0.031, -0.533,  0.45,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+  - do:
+      indices.put_mapping:
+        index: vectors_64
+        body:
+          properties:
+            embedding:
+              type: dense_vector
+              dims: 64
+              index_options:
+                type: bbq_flat
+
+  - do:
+      indices.get_mapping:
+        index: vectors_64
+
+  - match: { vectors_64.mappings.properties.embedding.type: dense_vector }
+  - match: { vectors_64.mappings.properties.embedding.index_options.type: bbq_flat }
+
+  - do:
+      index:
+        index: vectors_64
+        id: "2"
+        body:
+          vector: [0.196,  0.514,  0.039,  0.555, -0.042,  0.242,  0.463, -0.348,
+                   -0.08 ,  0.442, -0.067, -0.05 , -0.001,  0.298, -0.377,  0.048,
+                   0.307,  0.159,  0.278,  0.119, -0.057,  0.333, -0.289, -0.438,
+                   -0.014,  0.361, -0.169,  0.292, -0.229,  0.123,  0.031, -0.138,
+                   -0.139,  0.315, -0.216,  0.322, -0.445, -0.059,  0.071,  0.429,
+                   -0.602, -0.142,  0.11 ,  0.192,  0.259, -0.241,  0.181, -0.166,
+                   0.082,  0.107, -0.05 ,  0.155,  0.011,  0.161, -0.486,  0.569,
+                   -0.489,  0.901,  0.208,  0.011, -0.209, -0.153, -0.27 , -0.013]
+
+  - do:
+      index:
+        index: vectors_64
+        id: "3"
+        body:
+          name: rabbit.jpg
+          vector: [0.139,  0.178, -0.117,  0.399,  0.014, -0.139,  0.347, -0.33 ,
+                   0.139,  0.34 , -0.052, -0.052, -0.249,  0.327, -0.288,  0.049,
+                   0.464,  0.338,  0.516,  0.247, -0.104,  0.259, -0.209, -0.246,
+                   -0.11 ,  0.323,  0.091,  0.442, -0.254,  0.195, -0.109, -0.058,
+                   -0.279,  0.402, -0.107,  0.308, -0.273,  0.019,  0.082,  0.399,
+                   -0.658, -0.03 ,  0.276,  0.041,  0.187, -0.331,  0.165,  0.017,
+                   0.171, -0.203, -0.198,  0.115, -0.007,  0.337, -0.444,  0.615,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+
+  - do:
+      indices.refresh: { }
+  - do:
+      search:
+        index: vectors_64
+        body:
+          knn:
+            field: vector
+            query_vector: [ 0.128,  0.067, -0.08 ,  0.395, -0.11 , -0.259,  0.473, -0.393,
+                            0.292,  0.571, -0.491,  0.444, -0.288,  0.198, -0.343,  0.015,
+                            0.232,  0.088,  0.228,  0.151, -0.136,  0.236, -0.273, -0.259,
+                            -0.217,  0.359, -0.207,  0.352, -0.142,  0.192, -0.061, -0.17 ,
+                            -0.343,  0.189, -0.221,  0.32 , -0.301, -0.1  ,  0.005,  0.232,
+                            -0.344,  0.136,  0.252,  0.157, -0.13 , -0.244,  0.193, -0.034,
+                            -0.12 , -0.193, -0.102,  0.252, -0.185, -0.167, -0.575,  0.582,
+                            -0.426,  0.983,  0.212,  0.204,  0.03 , -0.276, -0.425, -0.158 ]
+            k: 3
+            num_candidates: 3
+
+  - match: { hits.hits.0._id: "1" }
+  - match: { hits.hits.1._id: "3" }
+  - match: { hits.hits.2._id: "2" }
+---
+"Test update int8_hnsw --> bbq_hnsw":
+  - requires:
+      capabilities:
+        - method: POST
+          path: /_search
+          capabilities: [ optimized_scalar_quantization_bbq ]
+      test_runner_features: capabilities
+      reason: "BBQ is required to test upgrading to bbq_flat and bbq_hnsw"
+  - requires:
+      reason: 'dense_vector updatable to bbq capability required'
+      test_runner_features: [ capabilities ]
+      capabilities:
+        - method: PUT
+          path : /_mapping
+          capabilities: [ dense_vector_updatable_bbq ]
+  - do:
+      indices.create:
+        index: vectors_64
+        body:
+          settings:
+            index:
+              number_of_shards: 1
+          mappings:
+            properties:
+              vector:
+                type: dense_vector
+                dims: 64
+                index: true
+                similarity: max_inner_product
+                index_options:
+                  type: int8_hnsw
+
+  - do:
+      index:
+        index: vectors_64
+        id: "1"
+        body:
+          vector: [0.077,  0.32 , -0.205,  0.63 ,  0.032,  0.201,  0.167, -0.313,
+                   0.176,  0.531, -0.375,  0.334, -0.046,  0.078, -0.349,  0.272,
+                   0.307, -0.083,  0.504,  0.255, -0.404,  0.289, -0.226, -0.132,
+                   -0.216,  0.49 ,  0.039,  0.507, -0.307,  0.107,  0.09 , -0.265,
+                   -0.285,  0.336, -0.272,  0.369, -0.282,  0.086, -0.132,  0.475,
+                   -0.224,  0.203,  0.439,  0.064,  0.246, -0.396,  0.297,  0.242,
+                   -0.028,  0.321, -0.022, -0.009, -0.001  ,  0.031, -0.533,  0.45,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+
+  - do:
+      index:
+        index: vectors_64
+        id: "2"
+        body:
+          vector: [0.196,  0.514,  0.039,  0.555, -0.042,  0.242,  0.463, -0.348,
+                   -0.08 ,  0.442, -0.067, -0.05 , -0.001,  0.298, -0.377,  0.048,
+                   0.307,  0.159,  0.278,  0.119, -0.057,  0.333, -0.289, -0.438,
+                   -0.014,  0.361, -0.169,  0.292, -0.229,  0.123,  0.031, -0.138,
+                   -0.139,  0.315, -0.216,  0.322, -0.445, -0.059,  0.071,  0.429,
+                   -0.602, -0.142,  0.11 ,  0.192,  0.259, -0.241,  0.181, -0.166,
+                   0.082,  0.107, -0.05 ,  0.155,  0.011,  0.161, -0.486,  0.569,
+                   -0.489,  0.901,  0.208,  0.011, -0.209, -0.153, -0.27 , -0.013]
+  - do:
+      indices.flush:
+        index: vectors_64
+  - do:
+      indices.put_mapping:
+        index: vectors_64
+        body:
+          properties:
+            embedding:
+              type: dense_vector
+              dims: 64
+              index_options:
+                type: bbq_hnsw
+
+  - do:
+      indices.get_mapping:
+        index: vectors_64
+
+  - match: { vectors_64.mappings.properties.embedding.type: dense_vector }
+  - match: { vectors_64.mappings.properties.embedding.index_options.type: bbq_hnsw }
+
+  - do:
+      index:
+        index: vectors_64
+        id: "3"
+        body:
+          name: rabbit.jpg
+          vector: [0.139,  0.178, -0.117,  0.399,  0.014, -0.139,  0.347, -0.33 ,
+                   0.139,  0.34 , -0.052, -0.052, -0.249,  0.327, -0.288,  0.049,
+                   0.464,  0.338,  0.516,  0.247, -0.104,  0.259, -0.209, -0.246,
+                   -0.11 ,  0.323,  0.091,  0.442, -0.254,  0.195, -0.109, -0.058,
+                   -0.279,  0.402, -0.107,  0.308, -0.273,  0.019,  0.082,  0.399,
+                   -0.658, -0.03 ,  0.276,  0.041,  0.187, -0.331,  0.165,  0.017,
+                   0.171, -0.203, -0.198,  0.115, -0.007,  0.337, -0.444,  0.615,
+                   -0.683,  1.331,  0.194, -0.157, -0.1  , -0.279, -0.098, -0.176]
+  - do:
+      indices.flush:
+        index: vectors_64
+  - do:
+      indices.refresh: { }
+  - do:
+      search:
+        index: vectors_64
+        body:
+          knn:
+            field: vector
+            query_vector: [ 0.128,  0.067, -0.08 ,  0.395, -0.11 , -0.259,  0.473, -0.393,
+                            0.292,  0.571, -0.491,  0.444, -0.288,  0.198, -0.343,  0.015,
+                            0.232,  0.088,  0.228,  0.151, -0.136,  0.236, -0.273, -0.259,
+                            -0.217,  0.359, -0.207,  0.352, -0.142,  0.192, -0.061, -0.17 ,
+                            -0.343,  0.189, -0.221,  0.32 , -0.301, -0.1  ,  0.005,  0.232,
+                            -0.344,  0.136,  0.252,  0.157, -0.13 , -0.244,  0.193, -0.034,
+                            -0.12 , -0.193, -0.102,  0.252, -0.185, -0.167, -0.575,  0.582,
+                            -0.426,  0.983,  0.212,  0.204,  0.03 , -0.276, -0.425, -0.158 ]
+            k: 3
+            num_candidates: 3
+
+  - match: { hits.hits.0._id: "1" }
+  - match: { hits.hits.1._id: "3" }
+  - match: { hits.hits.2._id: "2" }

server/src/main/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapper.java

@@ -1588,7 +1588,9 @@ public class DenseVectorFieldMapper extends FieldMapper {
                 || update.type.equals(VectorIndexType.HNSW)
                 || update.type.equals(VectorIndexType.INT8_HNSW)
                 || update.type.equals(VectorIndexType.INT4_HNSW)
-                || update.type.equals(VectorIndexType.INT4_FLAT);
+                || update.type.equals(VectorIndexType.BBQ_HNSW)
+                || update.type.equals(VectorIndexType.INT4_FLAT)
+                || update.type.equals(VectorIndexType.BBQ_FLAT);
         }
     }
 
@@ -1695,12 +1697,14 @@ public class DenseVectorFieldMapper extends FieldMapper {
 
         @Override
         boolean updatableTo(IndexOptions update) {
-            boolean updatable = update.type.equals(this.type);
-            if (updatable) {
+            boolean updatable = false;
+            if (update.type.equals(VectorIndexType.INT4_HNSW)) {
                 Int4HnswIndexOptions int4HnswIndexOptions = (Int4HnswIndexOptions) update;
                 // fewer connections would break assumptions on max number of connections (based on largest previous graph) during merge
                 // quantization could not behave as expected with different confidence intervals (and quantiles) to be created
                 updatable = int4HnswIndexOptions.m >= this.m && confidenceInterval == int4HnswIndexOptions.confidenceInterval;
+            } else if (update.type.equals(VectorIndexType.BBQ_HNSW)) {
+                updatable = ((BBQHnswIndexOptions) update).m >= m;
             }
             return updatable;
         }
@@ -1758,7 +1762,9 @@ public class DenseVectorFieldMapper extends FieldMapper {
             return update.type.equals(this.type)
                 || update.type.equals(VectorIndexType.HNSW)
                 || update.type.equals(VectorIndexType.INT8_HNSW)
-                || update.type.equals(VectorIndexType.INT4_HNSW);
+                || update.type.equals(VectorIndexType.INT4_HNSW)
+                || update.type.equals(VectorIndexType.BBQ_HNSW)
+                || update.type.equals(VectorIndexType.BBQ_FLAT);
         }
 
     }
@@ -1840,7 +1846,8 @@ public class DenseVectorFieldMapper extends FieldMapper {
                     || int8HnswIndexOptions.confidenceInterval != null
                         && confidenceInterval.equals(int8HnswIndexOptions.confidenceInterval);
             } else {
-                updatable = update.type.equals(VectorIndexType.INT4_HNSW) && ((Int4HnswIndexOptions) update).m >= this.m;
+                updatable = update.type.equals(VectorIndexType.INT4_HNSW) && ((Int4HnswIndexOptions) update).m >= this.m
+                    || (update.type.equals(VectorIndexType.BBQ_HNSW) && ((BBQHnswIndexOptions) update).m >= m);
             }
             return updatable;
         }
@@ -1874,7 +1881,8 @@ public class DenseVectorFieldMapper extends FieldMapper {
             }
             return updatable
                 || (update.type.equals(VectorIndexType.INT8_HNSW) && ((Int8HnswIndexOptions) update).m >= m)
-                || (update.type.equals(VectorIndexType.INT4_HNSW) && ((Int4HnswIndexOptions) update).m >= m);
+                || (update.type.equals(VectorIndexType.INT4_HNSW) && ((Int4HnswIndexOptions) update).m >= m)
+                || (update.type.equals(VectorIndexType.BBQ_HNSW) && ((BBQHnswIndexOptions) update).m >= m);
         }
 
         @Override
@@ -1924,7 +1932,7 @@ public class DenseVectorFieldMapper extends FieldMapper {
 
         @Override
         boolean updatableTo(IndexOptions update) {
-            return update.type.equals(this.type);
+            return update.type.equals(this.type) && ((BBQHnswIndexOptions) update).m >= this.m;
         }
 
         @Override
@@ -1978,7 +1986,7 @@ public class DenseVectorFieldMapper extends FieldMapper {
 
         @Override
         boolean updatableTo(IndexOptions update) {
-            return update.type.equals(this.type);
+            return update.type.equals(this.type) || update.type.equals(VectorIndexType.BBQ_HNSW);
         }
 
         @Override

server/src/main/java/org/elasticsearch/rest/action/search/SearchCapabilities.java

@@ -48,6 +48,7 @@ public final class SearchCapabilities {
     private static final String SIGNIFICANT_TERMS_BACKGROUND_FILTER_AS_SUB = "significant_terms_background_filter_as_sub";
     private static final String SIGNIFICANT_TERMS_ON_NESTED_FIELDS = "significant_terms_on_nested_fields";
     private static final String EXCLUDE_VECTORS_PARAM = "exclude_vectors_param";
+    private static final String DENSE_VECTOR_UPDATABLE_BBQ = "dense_vector_updatable_bbq";
 
     public static final Set<String> CAPABILITIES;
     static {
@@ -68,6 +69,7 @@ public final class SearchCapabilities {
         capabilities.add(SIGNIFICANT_TERMS_BACKGROUND_FILTER_AS_SUB);
         capabilities.add(SIGNIFICANT_TERMS_ON_NESTED_FIELDS);
         capabilities.add(EXCLUDE_VECTORS_PARAM);
+        capabilities.add(DENSE_VECTOR_UPDATABLE_BBQ);
         CAPABILITIES = Set.copyOf(capabilities);
     }
 }

server/src/test/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapperTests.java

@@ -275,6 +275,36 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                 .endObject(),
             m -> assertTrue(m.toString().contains("\"type\":\"int4_hnsw\""))
         );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_flat")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_flat\""))
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
         // update for int8_flat
         checker.registerUpdateCheck(
             b -> b.field("type", "dense_vector")
@@ -355,6 +385,36 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                     .endObject()
             )
         );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int8_flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_flat")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_flat\""))
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int8_flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
         // update for hnsw
         checker.registerUpdateCheck(
             b -> b.field("type", "dense_vector")
@@ -480,6 +540,40 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                     .endObject()
             )
         );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            )
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "hnsw")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
         // update for int8_hnsw
         checker.registerUpdateCheck(
             b -> b.field("type", "dense_vector")
@@ -591,6 +685,40 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                     .endObject()
             )
         );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            )
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int8_hnsw")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
         // update for int4_flat
         checker.registerUpdateCheck(
             b -> b.field("type", "dense_vector")
@@ -677,6 +805,36 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                     .endObject()
             )
         );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int4_flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_flat")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_flat\""))
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int4_flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
         // update for int4_hnsw
         checker.registerUpdateCheck(
             b -> b.field("type", "dense_vector")
@@ -853,6 +1011,285 @@ public class DenseVectorFieldMapperTests extends MapperTestCase {
                     .endObject()
             )
         );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int4_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            )
+        );
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "int4_hnsw")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
+        // update for bbq_flat
+        checker.registerUpdateCheck(
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_flat")
+                .endObject(),
+            b -> b.field("type", "dense_vector")
+                .field("dims", dims * 16)
+                .field("index", true)
+                .startObject("index_options")
+                .field("type", "bbq_hnsw")
+                .endObject(),
+            m -> assertTrue(m.toString().contains("\"type\":\"bbq_hnsw\""))
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int4_flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "hnsw")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_hnsw")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_flat")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_hnsw")
+                    .endObject()
+            )
+        );
+        // update for bbq_hnsw
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int4_flat")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "hnsw")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int8_hnsw")
+                    .endObject()
+            )
+        );
+        checker.registerConflictCheck(
+            "index_options",
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "bbq_hnsw")
+                    .endObject()
+            ),
+            fieldMapping(
+                b -> b.field("type", "dense_vector")
+                    .field("dims", dims * 16)
+                    .field("index", true)
+                    .startObject("index_options")
+                    .field("type", "int4_hnsw")
+                    .endObject()
+            )
+        );
     }
 
     @Override