    ALTER SYSTEM
      { archive_log_clause
      | checkpoint_clause
      | check_datafiles_clause
      | distributed_recov_clauses
      | FLUSH { SHARED_POOL | BUFFER_CACHE }
      | end_session_clauses
      | SWITCH LOGFILE
      | { SUSPEND | RESUME }
      | quiesce_clauses
      | alter_system_security_clauses
      | shutdown_dispatcher_clause
      | REGISTER
      | SET alter_system_set_clause
            [ alter_system_set_clause ]...
      | RESET alter_system_reset_clause
              [ alter_system_reset_clause ]...
      } ;