IDB_ffTrxBufferParameter in IDB_applicationConfig.ini
Defines the number of future spare daily partitions that the maintenance process will create. This provides a buffer if maintenance isn't run successfully for a few days. Typically configured to 7 - 30 daily partitions. Default value is 10.

IDB_ffTrxLookbackParameter in IDB_applicationConfig.ini
defines the number of days that FF(IFM) transactions are retained in IDB