Comment 1 for bug 1721123

Driver private data was designed to store items that drivers can manipulate, along the design, we may have percolated the idea that driver_private_data is analogous to any other table that is part of the Manila database schema, it isn't.

Manila database has hooks, and there are genuine use cases when Administrators of a Manila installation can access or manipulate data outside of the manila-api (that's the reason why manila-manage exists). Our database schema thus has a contract on upgrades or retention for audits. The same thing cannot be said of driver_private_data. Drivers are free to store whatever they want, since it is a key-value store, and there are no hard-binding upgrade or retention procedures as opposed to any other table/store that is part of the schema.

With that said, I think we should hard delete rows from this store, there is absolutely no valid reason why data deleted by the driver needs to be accessible after deletes.