@Override
  public void closeOperation(OperationHandle opHandle)
      throws HiveSQLException {
    sessionManager.getOperationManager().getOperation(opHandle)
    .getParentSession().closeOperation(opHandle);
    LOG.debug(opHandle + ": closeOperation");
  }
If this is a background operation run asynchronously,
we block for a duration determined by a step function, before we return
However, if the background operation is complete, we return immediately.
service/src/java/org/apache/hive/service/cli/CLIService.java