Documentation needed for DB upgrade as part of 2.0 #12769
Description
Following up on the dev call on 30th of November, there was a clear desire expressed for documentation around the database upgrade process from Airflow 1.10.14 (or equivalent) to Airflow 2.0. Though the upgrade process is conceptually no different from a regular 1.10.x to a 1.10.x+1 release, the fact that there are significant known database changes may raise concerns in the minds of Airflow users as part of the upgrade.
To ease their concerns, the following questions should ideally be answered as part of the documentation specifically either as part of the "Upgrading to 2.0 document" or linked from there.
Q 1. Is there anything "special" which I need to be done to upgrade from 1.10.x to 2.0 with respect to the database?
Ans. I don't believe so, other than the normal upgrade checks.
Q 2. How long should I expect this database upgrade expected to take?
Ans. I am not quite sure how to answer this since it depends on the data. We can possibly share sample times based on tested data sets.
Q 3. Can I do something to reduce the database upgrade time?
Ans. A couple of options here. One possibility is to recommend the maintenance DAGs to be run to archive / delete older task history, xcom data, and equivalent. Another possibility is to provide a script for them to run as part of the Airflow project distribution, possibly part of upgrade check scripts.