This is a good topic. I take the approach that EVERYTHING that's currently in my house right now might NOT survive a house fire. That includes things in my fire resistant gun safe. So, here's what I do. It is not advice for anyone. I'm just sharing.

I scan documents into my computer and backup the scans locally and remotely. The local back up is an external hard drive. (Most people already have one.) The external backup is an Internet backup service that houses encrypted databases. The environment for the databases is way more secure than any database I can build. All my computer backups are updated nightly. The costs for the computer backups is not much, especially if you already have an external hard drive. I also keep the original documents in a fireproof safe at home.

It's all about layered security! If there is another layer of security that will fit into my system, then I certainly have an open mind to consider it.