> That's definitely not true. What if you were planning on filtering after the join? You may find yourself pulling millions of records. The bandwidth alone woul

> That's definitely not true. What if you were planning on filtering after the join? You may find yourself pulling millions of records. The bandwidth alone would bring you down. I work with MongoDB, and once in awhile I really miss joins. You can't emulate joins in any reasonable amount of time in Mongo. I agree that joins should be done by mongo (as a feature, similar to RethinkDB), but they can get you in trouble when you convert your collection from local-to-joined-one into sharded-into-multiple-servers. You'd then gain huge network load that can potentially bring your system down. If you decided that data in some particular collection is potentially huge -- just don't use joins on it (unless REALLY once in a while).