If you want to allow the users to take the db offline, you will still be happiest giving each user or group their own database. Databases are just a file on the

If you want to allow the users to take the db offline, you will still be happiest giving each user or group their own database. Databases are just a file on the server, and CouchDB has been deployed with millions of databases on a single server. So the one database per user model is totally viable.