private int parseSgLevel() throws IllegalPathException {
    return new PartialPath(database).getNodeLength() - 1;
  }
This loader is used to load tsFiles. If .mods file exists, it will be loaded as well.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/receiver/protocol/legacy/loader/TsFileLoader.java