@Override
  public void close() throws Exception {
    if (leftChild != null) {
      leftChild.close();
    }
    if (rightChild != null) {
      rightChild.close();
    }

    if (!rightBlockList.isEmpty()) {
      for (TsBlock block : rightBlockList) {
        memoryReservationManager.releaseMemoryCumulatively(block.getRetainedSizeInBytes());
      }
    }
  }
@return true if current right block is consumed up
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/source/relational/AbstractMergeSortJoinOperator.java