Cassandra/Pycassa: Getting random rows
You might be able to do this by making a get_range request with a random start key (just a random string), and a row_count of 1. 
From memory, I think the finish key would need to be the same as start, so that the query 'wraps around' the keyspace; this would normally return all rows, but the row_count will limit that.
Haven't tried it but this should ensure you get a single result without having to know exact row keys.
Is there a possibility to retrieve random rows from Cassandra (using it with Python/Pycassa)?
Update: With random rows I mean randomly selected rows!