Fix Version/s: None
When having a big number of vnodes (such as 256/node advised by http://www.datastax.com/dev/blog/upgrading-an-existing-cluster-to-vnodes), using secondary indices becomes really slow because Cassandra has to search for the index in all the nodes.
This results in very slow queries (in the order of 1-2s).
For an exemple, see this tracing with a 3 physical nodes cluster with 256 vnodes on each.
The keyspace has a RF=3.