Seconded. This is the standard CouchDB approach: one database per user. Sounds weird coming from my Postgres and MySQL background, but works great in practice,

Seconded. This is the standard CouchDB approach: one database per user. Sounds weird coming from my Postgres and MySQL background, but works great in practice, depending on your use case and if you clear out old revisions and unused docs, which for our use case can number into the thousands fairly rapidly.