public void deRegisterFragmentInstanceFromMemoryPool(
      String queryId, String fragmentInstanceId, boolean forceDeregister) {
    localMemoryManager
        .getQueryPool()
        .deRegisterFragmentInstanceFromQueryMemoryMap(queryId, fragmentInstanceId, forceDeregister);
  }
Each FI has only one ShuffleSinkHandle.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/exchange/MPPDataExchangeManager.java