Description of alter_system

ALTER SYSTEM
  { archive_log_clause
  | checkpoint_clause
  | check_datafiles_clause
  | distributed_recov_clauses
  | FLUSH { SHARED_POOL | GLOBAL CONTEXT | BUFFER_CACHE | FLASH_CACHE          
                | REDO TO target_db_name [ [ NO ] CONFIRM APPLY ] }
  | end_session_clauses
  | SWITCH LOGFILE
  | { SUSPEND | RESUME }
  | quiesce_clauses
  | rolling_migration_clauses
  | rolling_patch_clauses
  | security_clauses
  | affinity_clauses
  | shutdown_dispatcher_clause
  | REGISTER
  | SET alter_system_set_clause
        [ alter_system_set_clause ]...
  | RESET alter_system_reset_clause
          [ alter_system_reset_clause ]...
  | RELOCATE CLIENT client_id
  | ALTER SYSTEM CANCEL SQL ' session_id serial_number [ @instance_id ] [ sql_id ]'
  | FLUSH PASSWORDFILE_METADATA_CACHE
  } ;