r.table('todos').get(todo_id).run(g.rdb_conn)

    g.rdb_conn.run(r.table('todos').get(todo_id))

Also, you are opening and closing DB connections with each HTTP request. I imagine this is for the purpose of simplifying the example. However, it does make me curious: how expensive is the creation of a new connection? Are connections thread-safe? Would it make sense to have connection pooling?

The distinction between query.run(conn) and conn.run(query) is very fine indeed. There has been much discussion about this and there are both solutions have their merits. At one point we even supported both but decided the simplicity of having only one solution merited dropping the other.

Creating a new connection involves opening a TCP connection and sending a message to validate the driver to the server, altogether a few round trips. There is a small bit of per connection state stored on the server but since RethinkDB uses a custom coroutine implementation for concurrency support this does not amount to the overhead of an independent OS thread for each connection.

Invoking the query with a specific connection object is thread safe. There is a feature designed to help REPL users that stores the last connection in global state that is slated for removal in the upcoming release (1.4) that is obviously not re-entrant.

It would make sense to have connection pooling, especially in the python driver where connections block on requests. This is an idea we're exploring but is lower down on the priority list. As it is a fully client side feature there is nothing stopping 3rd party driver developers from implementing a solution though the official drivers will have to wait for other priorities.

I don't know if I'd call it an issue with the API -- there is a pretty active debate going on about it: https://github.com/rethinkdb/rethinkdb/issues/256 Please chime in there with your POV, it would really help!

how expensive is the creation of a new connection?

Connections aren't thread safe on the clients. It's very efficient to open a connection to the server, but it still requires a TCP handshake. This is a good low-level API -- we'll build a connection pool on top of that soon (I just opened an issue for it here -- https://github.com/rethinkdb/rethinkdb/issues/281). People seem to want one because they're used to one, but it hasn't really been necessary in our testing.

    g.rdb_conn.table('todos').get(todo_id).run()

I am putting together a patch and instructions for fedora, but this is silly.

EDIT: https://gist.github.com/4696023 Turned out to not be too big of a change BTW.

If you only knew how much we agree with you :) We have an engineer working on that now, so it will soon be much, much nicer. Also, thanks for the instructions, I'll post them on the build page after I confirm everything.

If you want to have a look at what we need to hack our way around, take a look at https://aur.archlinux.org/packages/re/rethinkdb/PKGBUILD

As a boring non-cutting-edge, non-expert Rails person, any word on projects a la Mongoid to give a nice ActiveRecord-style ODM to guys like us? Would LOVE to be able to play with Rethink in place of Mongo.

(Also, as an aside, if I were about 3 years more advanced in my ruby skills I'd totally volunteer to start that project. But I'm not. So I can't ;)

Keep up the good work guys.

Thanks for your interest -- we'd really love to get everything out ASAP, but the team has limited resources and we have some more low-hanging fruit to take care of first.

No Python ORM :-(

What the other comment-er is asking for is a hosted instance.

http://www.youtube.com/watch?v=2ZUNLV7e3vU

"Star Trek - Data asks his creator a question"