public static TimeIndexLevel valueOf(int ordinal) {
    if (ordinal < 0 || ordinal >= values().length) {
      throw new IndexOutOfBoundsException("Invalid ordinal");
    }
    return values()[ordinal];
  }
array device to time index (large memory foot print)
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/tsfile/timeindex/TimeIndexLevel.java