I know that compression is enabled for SSTables by default. And the default compression used is snappy. I can disable or change the compression used with the sstable_compression storage option. I recently learned that compression is also enabled for system tables as well; however, the compression for system tables cannot be changed. This means that if snappy is available for the JRE/platform, then snappy compression will be used for system tables. As I understand, compression for system tables is disabled only when snappy is not available. In that scenario, I choose a different implementation of ICompressor for user tables, but I have no such option for system tables. Nor do I have the option to disable compression for all tables.