change log for a specific user in HANA

Hi SAP Gurus,

I am new to SAP HANA.

We have recently had an issue with one of the users in our HANA system where in certain Roles for the user got deleted due to which some of the jobs tied up with this user got failed. So we need to find out when these roles got removed and by whom. Please let me know if there is any table from which we can get this information.

Thanks,

Arjun