This does not matter. I'm author of another KV store (Redis), but years ago got real-time chat working with MySQL, check this:<p><a href="http://w.ebchat.com/channel/hackernews" rel="nofollow">http://w.ebchat.com/channel/hackernews</a><p>You can do it with MySql, or with <i>files</i> in append mode with "message_id - message", and everything else.<p>I think that KV stores are great, but if you create a false sense of coolness this is going to hurt in the long run. It is important to show people <i>why</i> really new forms of DBs can be useful and important.<p>edit: If the point is instead the fact that the DB talks directly HTTP, the w.ebchat.com chat PHP layer is ridiculous, just a wrapper that takes parameters from the HTTP side and run a query returning back the data. I can only see the HTTP protocol as interface to KV DB as a good way to lost a lot of performances without a reason.