I did not know this.
Is there a way to control Auto_Purge Frequency done by the MMON ? (Doc ID 1446242.1)
The automatic purge cycle is designed as follows. (1) The first actual purge action will be 2 days after instance startup time (2) The next automatic purge actions following this first purge is done once every 7 days
If you like to purge more often, then it will need to be done manually.