Is it possible to create a copy of the database, and keep it available for as long as needed?
Daily snapshots are taken automatically for all Campaign instances, and each snapshot is available for 14 days. Once deleted, these cannot be restored by you.
If you want to keep a copy of the database for an extended period of time, reach out to Support. Support will then have TechOps take a manual DB snapshot. These snapshots are available indefinitely and can be removed manually when needed.