[codecaine]

Redis operations are performed in RAM and while you can specify an interval where its contents should be written to disk you risk loosing some data if it closes unexpectedly. If that is not a problem I don't see why it couldnt be used as the sole datastorage.

[pjscott]

That's not quite true; Redis also provides an append-only-log mode of operation just like conventional databases, and of course it can be run with master-slave replication. I wrote a bigger reply here:

http://news.ycombinator.com/item?id=3010949