I've talked about HCC (Hybrid Columnar Compression) before. This is Oracle's built-in compression feature, free of charge in 11Gr2, that allows a CRAZY amount of compression on historical data inside an Oracle database. It only works if the database is being stored in a ZFSSA, Exadata or Axiom. You can read all about it in this whitepaper, which shows the huge value of HCC when used with the ZFSSA. http://www.oracle.com/technetwork/articles/servers-storage-admin/perf-hybrid-columnar-compression-1689701.html
Now, even better, Oracle has announced a great new feature in Oracle 12c called "Automatic Data Optimization". This allows one to setup HCC to AUTOMATICALLY compress data AS IT AGES.
So this is now ILM all built into the Oracle database. It's free for crying out loud. It just needs to be sitting on Oracle storage, such as the ZFSSA, Exadata or Axiom.