https://stackoverflow.com/questions/57481237/use-case-of-dummy-operator 채택 답변 참고
Operator that does literally nothing. It can be used to group tasks in a DAG.
https://airflow.apache.org/_api/airflow/operators/dummy_operator/index.html
as far as I know, at least to two case:
test purpose. in dags, the dummy operation just between upstream and downstream, later, you can replace the true operator.
Workflow purpose: BranchPythonOperator work with DummyOperator. If you want to skip some tasks, keep in mind that you can’t have an empty path, if so make a dummy task.
https://airflow.apache.org/concepts.html#workflows