Small iceberg read optimization

src/Interpreters/ClusterFunctionReadTask.cpp

@@ -19,9 +19,11 @@ namespace ErrorCodes
 namespace Setting
 {
     extern const SettingsBool cluster_function_process_archive_on_multiple_nodes;
+    extern const SettingsBool allow_experimental_iceberg_read_optimization;
 }
 
 ClusterFunctionReadTaskResponse::ClusterFunctionReadTaskResponse(ObjectInfoPtr object, const ContextPtr & context)
+    : iceberg_read_optimization_enabled(context->getSettingsRef()[Setting::allow_experimental_iceberg_read_optimization])
 {
     if (!object)
         throw Exception(ErrorCodes::LOGICAL_ERROR, "`object` cannot be null");
@@ -67,7 +69,8 @@ void ClusterFunctionReadTaskResponse::serialize(WriteBuffer & out, size_t protoc
 
     if (protocol_version >= DBMS_CLUSTER_PROCESSING_PROTOCOL_VERSION_WITH_DATA_LAKE_COLUMNS_METADATA)
     {
-        if (file_meta_info.has_value())
+        /// This info is not used when optimization is disabled, so there is no need to send it.
+        if (iceberg_read_optimization_enabled && file_meta_info.has_value())
             file_meta_info.value()->serialize(out);
         else
             DataFileMetaInfo().serialize(out);

src/Interpreters/ClusterFunctionReadTask.h

@@ -23,6 +23,8 @@ struct ClusterFunctionReadTaskResponse
     /// File's columns info
     std::optional<DataFileMetaInfoPtr> file_meta_info;
 
+    const bool iceberg_read_optimization_enabled = false;
+
     /// Convert received response into ObjectInfo.
     ObjectInfoPtr getObjectInfo() const;