How to securely delete DB on Android?

My app uses SQLite DB in Android to keep some logs. I understand this is saved in my app dir on Android as DBName.db. I need a way to truncate/delete/damage/empty the database so it is unrecoverable.

1. What is the best approach?

2. Does Android keep some shadow copies on the device?

3. Does Android keep synced backup in cloud by default (like settings are kept)?

4. If the app is running, is the whole db cached in RAM? If so, id like to clean that too.

Thanks :)