how to compact an index CF?

["Poziombka, Wade L" <wa...@intel.com>]

I have an index to a column IX in column family A.

How would I go about compacting that?  I have tried nodetool compact keyspace A.IX

But that complains "Unknown table/cf pair"

I'm sure there must be some simple magic to make this happen.  I just cannot tell what it is.