> We've eliminated most of the joins we do, so we haven't tested Cloud Spanner's join performance. The join performance is by far the most interesting part of

> We've eliminated most of the joins we do, so we haven't tested Cloud Spanner's join performance. The join performance is by far the most interesting part of this to me. A more traditional NoSQL solution sounds like it would have worked just as well for you, sans all the atomic clock fanciness. Joining across geographically disparate data is a real trick, and it seems like there would be some physical performance limits?