@Override
  public void close() throws IOException {
    while (!heap.isEmpty()) {
      Element e = heap.poll();
      e.close();
    }
    if (memoryReservationManager != null) {
      memoryReservationManager.releaseMemoryCumulatively(usedMemorySize);
    }
    usedMemorySize = 0;
  }
this method only take effect for aligned time series, so the override version.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/read/reader/common/PriorityMergeReader.java