Info on secondary indexes http://www.datastax.com/dev/blog/whats-new-cassandra-07-secondary-indexes
Some answers to your other questions are also in there as well as a discussion about the limitations.
Hope that helps.
On 7/03/2011, at 3:54 PM, Mark wrote:
I haven't looked at Cassandra since 0.6.6 and now I notice in 0.7+ there is support for secondary indexes. I haven't found much material on how these are used and when one should use one. Can someone point me in the right direction.
Also can these be created (and deleted) as needed without affecting the underlying CF? If so, I'm guessing there is no need to create another CF just for indexing. What are the disadvantages of this method?