Recommendations
Customer can set the retention period at the maintenance object level using the ILM Retention Period in Days Maintenance Object Option.
Oracle recommends using a value that aligns with the number of partitions. The formula is typically 30.1 * (# of partitions + next month + max).
•	Customer Care and Billing and Oracle Utilities Application Framework objects: 48 months (1461 days)
•	Meter Data Management objects: 13 months (400 days)
•	Initial Measurement Data: 3 months (90 days). 
Note: If the customer desires longer retention periods, this may have an impact on total database storage needs.