How to manuall purge your unified auditing audit trail

This is how I purged my unified audit trail on an Oracle 12.2 test instance.

First, check the LAST_ARCHIVE_TS:

SELECT * FROM DBA_AUDIT_MGMT_LAST_ARCH_TS;

If you want to keep some of your audit records, set a timestamp before which all records should be purged. In this case, I want to purge everything, so I set it to SYSTIMESTAMP:

BEGIN
  DBMS_AUDIT_MGMT.SET_LAST_ARCHIVE_TIMESTAMP (
    AUDIT_TRAIL_TYPE => DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED,
    LAST_ARCHIVE_TIME => SYSTIMESTAMP);
END;
/

Purge the audit trail:

BEGIN
  DBMS_AUDIT_MGMT.clean_audit_trail(
   audit_trail_type        => DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED,
   use_last_arch_timestamp => TRUE);
END;
/

If you want to purge all records, run the same procedure but without the "use_last_arch_timestamp" directive:

BEGIN
  DBMS_AUDIT_MGMT.clean_audit_trail(
   audit_trail_type => DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED
   );
END;
/

The dbms_audit_mgmt is documented here