Random record from MongoDB

Question

I am looking to get a random record from a huge (100 million record) mongodb.

What is the fastest and most efficient way to do so? The data is already t

Answer 1

If you have a simple id key, you could store all the id's in an array, and then pick a random id. (Ruby answer):

ids = @coll.find({},fields:{_id:1}).to_a
@coll.find(ids.sample).first