Good point, sounds like I intend to keep it that way for this particular database in my comment.

It's setup for multi box (each schema is mapped to a hostname in code) but I simply haven't had a reason to move to more boxes yet. The schema feature is a nice, convenient way to pre-shard like this so that growing to more boxes doesn't require rehashing for a very long time if ever (depending on how much sharding you do up front). You just move schemas/shards as needed using the standard dump and restore tools and update the schema->hostname mapping in the code.