public static Optional<String> getNonSystemDatabaseName(String databaseName) {
    if (Objects.isNull(databaseName)) {
      return Optional.empty();
    }
    if (databaseName.startsWith(SchemaConstant.SYSTEM_DATABASE)) {
      return Optional.empty();
    }
    int lastIndex = databaseName.lastIndexOf("-");
    if (lastIndex == -1) {
      lastIndex = databaseName.length();
    }
    return Optional.of(databaseName.substring(0, lastIndex));
  }
After finishing settling tsfile, we need to do 2 things : (1) move the new tsfile to the
correct folder, including deleting its old mods file (2) update the relevant data of this old
tsFile in memory ,eg: TsFileSequenceReader, {@link #tsFileManager}, cache, etc.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/DataRegion.java