Airflow Upgradedb issue

Hi All,
I am trying to upgrade db using “airflow upgradedb” command on version 1.10.2.My question is what if the upgradedb is done for airflow version 1.10.2,and if the user wants to move back to version 1.9.0 and again performs upgradedb on the same database,then it has to fail due to alembic revision tags missing issue.
Shouldn’t there be a way saying that tables for version 1.9.0 is already available hence upgrade should successfully pass?
The reason why am asking is the my db is already upgraded for version 1.10.2 when i was deploying airflow into EC2 but now am deploying airflow (version 1.8 to 1.9.0) into kubernetes pods acting on the same database,it says revision tags “41f5f12752f8” are missing.

Once the DB is migrated to a new version, you can’t downgrade it. And old versions of airflow will not work with a newer version of the dB.