Well, most of this thoughts about not needing a database assume a basic thing: You never shut down your application.
If this is a fact and you can guarantee that it will never shutdown, then leave DBs completely.
But since you can’t guarantee zero downtime, you have to persist your data somehow.
To persist your data and getting it back into your live system, you have a couple of options:
- Put them into a databse of any kind (SQL or not doesn’t matter) and reload it when necessary
- Log changes of the system into a file. On restart load that file and “replay”
- Combine both ways.
- probably others
One of the most important things to remember to understand that mantra is, that it means “you don’t need the database as primary source of truth, but it may be a valid backup strategy”.
