@Override
  public boolean stillLives(long ttlLowerBound) {
    if (ttlLowerBound == Long.MAX_VALUE) {
      return true;
    }
    // the file cannot be deleted if any device still lives
    return endTime >= ttlLowerBound;
  }
end times. The value is Long.MIN_VALUE if it's an unsealed sequence tsfile
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/tsfile/timeindex/FileTimeIndex.java