This is an interesting tidbit. The Database Licensing Guide here makes the following statement:

Basic Flashback Data Archive is in all editions. Optimization for Flashback Data Archive requires EE and the Advanced Compression option.”

As a result, the “Optimization for Flashback Data Archive” feature is seen as only available in the Enterprise Editiion in the table of features/options and editions in the licensing guide.

However, what exactly is the Basic Flashback Data Archive, that is available in all editions including SE1, SE and EE?

The interesting thing is that what is known as “Basic Flashback Data Archive”, actually includes all functionality of Flashback Data Archive; except for compression of the history tables that are managed by Flashback Data Archive.

For this compression, simply specify OPTIMIZE DATA when creating or altering a Flashback Data Archive.  This will enable optimization of data storage for the history tables that are maintained by Flashback Data Archive. The default is NO OPTIMIZE DATA, which signifies Basic Flashback Data Archive.

OPTIMIZE DATA optimizes the storage of data in history tables by using features such as Advanced Row or LOB Compression, or Advanced LOB Deduplication, or Segment-level/Row-level compression tiering.

To see more information for Flashback Data Archive,  you can refer to the documentation here.