On 10 June 2013 22:00, Emalayan Vairavanathan <svemalayan@yahoo.com> wrote:

                   b) Will Cassandra automatically take care of removing obsolete keys in future ?

In a future version Cassandra should automatically clean up for you:

https://issues.apache.org/jira/browse/CASSANDRA-5051

Right now though you have to run cleanup eventually or the space will never be reclaimed.

Richard.