> I'd also point out that CouchDB's biggest feature, the must-have feature no other NoSQL repo besides RavenDB replicates, is the master-master replication. If

> I'd also point out that CouchDB's biggest feature, the must-have feature no other NoSQL repo besides RavenDB replicates, is the master-master replication. If you don't need that, your barrier to entry with the other NoSQL solutions is much easier/straight forward. The other unique feature is incremental MapReduce. If you need to transform your mostly unchanging data in a way more complex than a mere attribute index, the ability for CouchDB to reuse parts of the last MapReduce operation is very convenient. Of course, if you want to do any transormations beyond one set of map and reduce operations, you're on your own. I think only [Twister][1] does iterative MapReduce at the moment, although I'm not sure if it is incremental or not. [1]: http://www.iterativemapreduce.org/ http://www.iterativemapreduce.org/