Oracle 12c has both ILM and Temporal Validation which can be confused in their use.   The definitions of each are below along with their use:

• ILM is used to improve the utilization of storage devices through compression and access tiering of data. Data accessed the least is compressed and placed on slow devices, while data accessed frequently is not compressed and stored on faster devices.
• Temporal Validity allows you define a valid time dimension for each row of a table.

Larry Catt

OCP