fix: stabilize backend services and frontend pointer

fastapi_modules/fastapi_leaudit/services/impl/ragDatasetServiceImpl.py

@@ -57,6 +57,8 @@ class RagDatasetServiceImpl(IRagDatasetService):
             ORDER BY dataset_id, is_default DESC, sort_order ASC, id ASC
         ) a ON a.dataset_id = d.id
     """
+    _tenant_schema_checked = False
+    _tenant_schema_lock = asyncio.Lock()
 
     def __init__(self) -> None:
         self.TenantResolver = TenantResolver()
@@ -1038,10 +1040,39 @@ class RagDatasetServiceImpl(IRagDatasetService):
             raise LeauditException(StatusCodeEnum.HTTP_403_FORBIDDEN, "当前用户只能管理本地区知识库")
 
     async def _ensure_rag_tenant_schema(self, session) -> None:
-        await session.execute(text("ALTER TABLE rag_dataset ADD COLUMN IF NOT EXISTS tenant_code VARCHAR(64) NULL"))
-        await session.execute(text("ALTER TABLE rag_chat_app ADD COLUMN IF NOT EXISTS tenant_code VARCHAR(64) NULL"))
-        await session.execute(text("CREATE INDEX IF NOT EXISTS idx_rag_dataset_tenant_code ON rag_dataset(tenant_code) WHERE deleted_at IS NULL"))
-        await session.execute(text("CREATE INDEX IF NOT EXISTS idx_rag_chat_app_tenant_code ON rag_chat_app(tenant_code) WHERE deleted_at IS NULL"))
+        if self.__class__._tenant_schema_checked:
+            return
+
+        async with self.__class__._tenant_schema_lock:
+            if self.__class__._tenant_schema_checked:
+                return
+
+            columns = (
+                await session.execute(
+                    text(
+                        """
+                        SELECT table_name
+                        FROM information_schema.columns
+                        WHERE table_schema = current_schema()
+                          AND table_name IN ('rag_dataset', 'rag_chat_app')
+                          AND column_name = 'tenant_code'
+                        """
+                    )
+                )
+            ).scalars().all()
+            existing = set(columns)
+            if existing == {"rag_dataset", "rag_chat_app"}:
+                self.__class__._tenant_schema_checked = True
+                return
+
+            await session.execute(text("SET LOCAL lock_timeout = '1000ms'"))
+            if "rag_dataset" not in existing:
+                await session.execute(text("ALTER TABLE rag_dataset ADD COLUMN tenant_code VARCHAR(64) NULL"))
+            if "rag_chat_app" not in existing:
+                await session.execute(text("ALTER TABLE rag_chat_app ADD COLUMN tenant_code VARCHAR(64) NULL"))
+            await session.execute(text("CREATE INDEX IF NOT EXISTS idx_rag_dataset_tenant_code ON rag_dataset(tenant_code) WHERE deleted_at IS NULL"))
+            await session.execute(text("CREATE INDEX IF NOT EXISTS idx_rag_chat_app_tenant_code ON rag_chat_app(tenant_code) WHERE deleted_at IS NULL"))
+            self.__class__._tenant_schema_checked = True
 
     def _dataset_tenant_filter_sql(
         self,