Compression may be enabled or disabled per cf, set per level in a cf, and separately for the bottom-most level. Thus, a newly created table may or may not be compressed, and different tables may be compressed using different compression algorithms.
The purpose of this feature is to present a global compression ratio, over all compressed tables.
So, only tables that were actually compressed (it is indicated in the table properties of the table_file_creation event) should participate in the calculation.
Compression may be enabled or disabled per cf, set per level in a cf, and separately for the bottom-most level. Thus, a newly created table may or may not be compressed, and different tables may be compressed using different compression algorithms. The purpose of this feature is to present a global compression ratio, over all compressed tables.
So, only tables that were actually compressed (it is indicated in the table properties of the table_file_creation event) should participate in the calculation.