In Memory Database as a backup for Database Failures

Question

Is in-memory database a viable backup option for performing read operations in case of database failures? One can insert data into an in-memory database once in a while and in case the database server/web server goes down (rare occurence), one can still access the data present in the in-memory database outside of web server.

Answer 1

Obviously it probably depends on your database usage. For instance it would be hard for me to imagine StackOverflow doing this.

On the other hand not every application is SO. If your database usage is limited you could take a cue from Mobile Applications which accept the fact that a server may not always be available. And treat your web application as though it were a Mobile Client. See Architecting Disconnected Mobile Applications Using a Service Oriented Architecture

Answer 2

If you're going to hold your entire database in memory, you might just as well perform all operations there and hold your backup on disk.

Answer 3

No, since a power outage means your database is gone. Or if the DB process dies, and the OS deallocates all the memory it was using.

I'd recommend a second hard drive, external or internal, and dump the data to that hard drive.