private MetricsPersistentWorker downSamplingWorker(ModuleDefineHolder moduleDefineHolder,
                                                       IMetricsDAO metricsDAO,
                                                       Model model,
                                                       boolean supportUpdate,
                                                       MetricStreamKind kind) {
        MetricsPersistentWorker persistentWorker = new MetricsPersistentWorker(
            moduleDefineHolder, model, metricsDAO,
            supportUpdate, storageSessionTimeout, metricsDataTTL, kind
        );
        persistentWorkers.add(persistentWorker);

        return persistentWorker;
    }
All metrics default are `supportDownSampling` and `insertAndUpdate`, unless it has explicit definition.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsStreamProcessor.java