> > In other words, if I am running Cassandra 1.2.x and upgrading to 2.0.x, > 2.0.x will continue to read all the old Cassandra 1.2.x table. However, if > I then want to upgrade to Cassandra 2.1.x, I’d better make sure all tables > have been upgraded to 2.0.x before making the next upgrade.
Correct but you should really upgrade SSTables as early as possible to benefit from any storage/performance improvements. Plus it's probably not incredibly safe to be running an old format with a newer version for an extended period.
