I'm hoping this'll be a viable replacement for MongoDB. (Sparse/Schema-free is incredibly useful for me, as is JSON-centric modeling) jedberg already asked for a compare/contrast, but let me provide some specifics I care about that you might be able to answer. 1. Is it fair to say that thanks to MVCC, running an aggregation or map-reduce job isn't going to lock the whole damn thing up like it does on MongoDB? 2. You'…
2. Short answer: we favor consistency (via master/slave under the hood). It allows for much easier API, much fewer issues in production, etc. The user experience is just better. If you're ok with out of date results, you can do that too without paying the price of consistency guarantees. The downsite of our design is that you might lose write availability in case of netsplits (if the client is on the wrong side of the split). Longer answer: checkout the FAQ at http://www.rethinkdb.com/docs/advanced-faq/
3. Read latency should be equivalent to other comparable master/slave systems. We don't do quorums, so latency will be much better than quorum/dynamo-based designs.