I haven’t done the like-for-like RDBMS comparison. However, I do have an RDBMS based system I looking to replace that can handle a peak of about 120 updates/sec on significantly superior hardware than my laptop. It’s also doing a lot more work than is demonstrated in the benchmark. If I added the rest of the updates and required indices, I suspect I’d probably be able to get 500 updates/sec with Berkeley DB and syncing after every request. That probably isn’t quite fast enough for my needs.

This is exactly the kind of comment that makes me keep blogging. Great information! I hadn’t come across Tokyo Cabinet and it looks like exactly what I have been looking for, for more than 5 years!

I had been intending to benchmark Redis next.

Cheers

* if you don’t need the full power of Storable, try JSON::XS: on my benchmarks is faster than Storable, and the end result is user readable and reusable from other languages;
* BerkleyDB is not the fastest disk DB in town. I would also experiment with Tokyo Cabinet (http://fallabs.com/tokyocabinet/);
* Also interesting to try would be Redis. Given that it would run on a separate process, with pipeline commands you should be able to get decent performance.