fix(dataset): rebuild vectors when embedding model changes (#7359)

* fix(dataset): rebuild vectors when embedding model changes

* docs: update v4.15.4 vector rebuild notes

document/content/self-host/upgrading/4-15/4154.en.mdx

@@ -11,3 +11,4 @@ description: 'FastGPT V4.15.4 Release Notes'
 
 1. Fixed an issue where Chatbox displayed system tool errors during streaming responses.
 2. Fixed an issue where plain-text tool responses in full run details could be incorrectly parsed as Markdown, causing formatting issues.
+3. Fixed an issue where switching the embedding model triggered training but did not rebuild vectors for existing data.

document/content/self-host/upgrading/4-15/4154.mdx

@@ -11,3 +11,4 @@ description: 'FastGPT V4.15.4 更新说明'
 
 1. chatbox 流输出时候，不应该展示系统工具的错误。
 2. 完整运行详情，纯文本的工具响应 UI 可能会被 Markdown 错误解析，格式错乱。
+3. 切换向量模型后，训练任务会触发但已有数据的向量未重建。

document/data/doc-last-modified.json

@@ -324,6 +324,8 @@
   "content/self-host/upgrading/4-15/4152.mdx": "2026-07-18T12:51:59+08:00",
   "content/self-host/upgrading/4-15/4153.en.mdx": "2026-07-18T12:51:59+08:00",
   "content/self-host/upgrading/4-15/4153.mdx": "2026-07-18T12:51:59+08:00",
+  "content/self-host/upgrading/4-15/4154.en.mdx": "2026-07-21T13:14:50+08:00",
+  "content/self-host/upgrading/4-15/4154.mdx": "2026-07-21T13:14:50+08:00",
   "content/self-host/upgrading/outdated/40.en.mdx": "2026-04-26T21:08:47+08:00",
   "content/self-host/upgrading/outdated/40.mdx": "2026-04-26T21:08:47+08:00",
   "content/self-host/upgrading/outdated/41.en.mdx": "2026-04-26T21:08:47+08:00",
@@ -464,6 +466,6 @@
   "content/self-host/upgrading/outdated/499.mdx": "2026-05-07T15:06:40+08:00",
   "content/self-host/upgrading/upgrade-intruction.en.mdx": "2026-04-26T21:08:47+08:00",
   "content/self-host/upgrading/upgrade-intruction.mdx": "2026-04-26T21:08:47+08:00",
-  "content/toc.en.mdx": "2026-07-18T12:51:59+08:00",
-  "content/toc.mdx": "2026-07-18T12:51:59+08:00"
+  "content/toc.en.mdx": "2026-07-21T13:14:50+08:00",
+  "content/toc.mdx": "2026-07-21T13:14:50+08:00"
 }
\ No newline at end of file

projects/app/src/service/core/dataset/data/data.ts

@@ -26,11 +26,13 @@ type UpdateDatasetDataByIndexesProps = Omit<UpdateDatasetDataPropsType, 'indexes
   model: string;
   indexSize?: number;
   imageIndex?: boolean;
+  /** 重建索引时忽略文本相同判断，确保切换 embedding model 后重新生成向量。 */
+  forceRebuild?: boolean;
 };
 
 type UpdateDatasetDataSystemIndexesProps = Omit<
   UpdateDatasetDataByIndexesProps,
-  'indexes' | 'q'
+  'indexes' | 'q' | 'forceRebuild'
 > & {
   q?: string;
   imageIndex?: boolean;
@@ -218,7 +220,8 @@ export class DatasetDataOperation {
     model,
     indexSize = 512,
     indexPrefix,
-    imageIndex
+    imageIndex,
+    forceRebuild = false
   }: UpdateDatasetDataByIndexesProps) {
     const embModel = getEmbeddingModel(model);
 
@@ -256,8 +259,11 @@ export class DatasetDataOperation {
     // patchResult 先保留旧 dataId；insertVectorForPatch 会为 create/update 项写入新向量并回填新 dataId。
     const patchResult = this.indexOperation.buildPatch({
       currentIndexes: mongoData.indexes,
-      nextIndexes: indexesWithExistingSystemIds
+      nextIndexes: indexesWithExistingSystemIds,
+      isSameIndex: forceRebuild ? () => false : undefined
     });
+    // 先保存旧向量 id；insertVectorForPatch 会原地把 update 项替换成新 dataId。
+    const deleteVectorIdList = this.indexOperation.getDeleteVectorIdList(patchResult);
 
     // 提前刷新 updateTime，方便 job 扫到该 data 进行处理。
     const updateTime = mongoData.updateTime;
@@ -272,7 +278,6 @@ export class DatasetDataOperation {
     });
 
     const newIndexes = this.indexOperation.getWritablePatchIndexes(patchResult);
-    const deleteVectorIdList = this.indexOperation.getDeleteVectorIdList(patchResult);
 
     await mongoSessionRun(async (session) => {
       // 仅在 Q/A 变化时记录历史，最多保留最近 10 条旧内容。

projects/app/src/service/core/dataset/queues/generateVector.ts

@@ -325,7 +325,8 @@ const rebuildData = async ({ trainingData }: { trainingData: TrainingDataType })
     indexSize: trainingData.indexSize || getMaxIndexSize(embModel),
     indexPrefix: trainingData.collection.indexPrefixTitle
       ? `# ${trainingData.collection.name}`
-      : undefined
+      : undefined,
+    forceRebuild: true
   });
 
   await mongoSessionRun(async (session) => {

projects/app/test/service/core/dataset/data/data.test.ts

@@ -360,6 +360,74 @@ describe('Dataset data service', () => {
       );
     });
 
+    it('should rebuild vectors when forceRebuild is enabled even if index text is unchanged', async () => {
+      const { data } = await createMongoData({
+        q: 'same question',
+        a: 'same answer',
+        indexes: [
+          {
+            type: DatasetDataIndexTypeEnum.custom,
+            text: 'same custom index',
+            dataId: 'custom_old'
+          },
+          {
+            type: DatasetDataIndexTypeEnum.default,
+            text: 'same question',
+            dataId: 'question_old'
+          },
+          {
+            type: DatasetDataIndexTypeEnum.default,
+            text: 'same answer',
+            dataId: 'answer_old'
+          }
+        ]
+      });
+
+      const result = await updateDatasetDataByIndexes({
+        dataId: String(data._id),
+        q: 'same question',
+        a: 'same answer',
+        indexes: [
+          {
+            type: DatasetDataIndexTypeEnum.custom,
+            text: 'same custom index',
+            dataId: 'custom_old'
+          }
+        ],
+        model: 'text-embedding-3-small',
+        indexSize: 50,
+        forceRebuild: true
+      });
+
+      const updatedData = await MongoDatasetData.findById(data._id).lean();
+      const deleteCall = mockVectorDelete.mock.calls[0]?.[0];
+
+      expect(result.tokens).toBeGreaterThan(0);
+      expect(mockVectorInsert).toHaveBeenCalledTimes(1);
+      expect(updatedData?.indexes).toEqual(
+        expect.arrayContaining([
+          expect.objectContaining({
+            type: DatasetDataIndexTypeEnum.custom,
+            text: 'same custom index',
+            dataId: 'id_1'
+          }),
+          expect.objectContaining({
+            type: DatasetDataIndexTypeEnum.default,
+            text: 'same question',
+            dataId: 'id_2'
+          }),
+          expect.objectContaining({
+            type: DatasetDataIndexTypeEnum.default,
+            text: 'same answer',
+            dataId: 'id_3'
+          })
+        ])
+      );
+      expect(deleteCall?.idList).toEqual(
+        expect.arrayContaining(['custom_old', 'question_old', 'answer_old'])
+      );
+    });
+
     it('should reject invalid update-by-indexes requests', async () => {
       const { data } = await createMongoData();