docs: private int primDelete(IPermission perm, PreparedStatement ps) throws Exception {
          ps.clearParameters();
          ps.setString(1, perm.getOwner());
          ps.setInt(2, getPrincipalType(perm));
          ps.setString(3, getPrincipalKey(perm));
          ps.setString(4, perm.getActivity());
          ps.setString(5, perm.getTarget());
          if (log.isDebugEnabled()) log.debug("RDBMPermissionImpl.primDelete(): " + ps);
  
          return ps.executeUpdate();
      }