This forum post might help you: https://forum.mendix.com/link/questions/16292
And the documentation on batches needs to be improved. There used to be examples but those have disappeared somehow. Best currently is this one: https://docs.mendix.com/howto7/monitoring-troubleshooting/detect-and-resolve-performance-issues#batches
But indeed currently the documentations on batches could be improved.
Regards,
Ronald