CouchDB: M2M link via non-primary keys.

gistfile1.js

// I have meetings like this:

{
  "type": "meeting"
  "_id": "MEETINGID",
  "emails": ["test1@example.com", "test2@example.com"]
  // Lots of others things
}

// I have users like this:
{
  "type": "user",
  "_id": "USERID",
  "emails": ["a@example.com", "test1@example.com"]
}

// I need to keep them linked via email. But I can definitely split out the emails into separate documents if that helps.

// I need to be able to lookup all users for a meeting and all meetings for a user. I can see lots of ways to lookup meetings by email and users by email, but that's as far as I get. All the solutions I can think of require multi-level map-reduce which wouldn't work with couch.

// I'm looking for a view that produces this:

{
  "key": "MEETING",
  "document": {/* user */}
}


// And one that does the inverse:

{
  "key": "USERID",
  "document": {/* meeting */}
}

// Ideas would be very welcome! :)