如何启动或关闭oracle的归档(ARCHIVELOG)模式

C:\Users\Administrator>sqlplus sys/sys@prjdb as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Tue Jun 17 23:50:55 2014Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> archive log list;Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     228Current log sequence           230

SQL> shutdown immediate;Database closed.Database dismounted.
ORACLE instance shut down.

SQL> startup mount;
ORACLE instance started.

Total System Global Area 3423965184 bytes
Fixed Size                  2180544 bytes
Variable Size            2013268544 bytesDatabase Buffers         1392508928 bytes
Redo Buffers               16007168 bytesDatabase mounted.

SQL> alter database archivelog;Database altered.

SQL> archive log list;Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     228Next log sequence to archive   230Current log sequence           230

SQL> alter database open;Database altered.

SQL> shutdown immediate;Database closed.Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 3423965184 bytes
Fixed Size                  2180544 bytes
Variable Size            2013268544 bytesDatabase Buffers         1392508928 bytes
Redo Buffers               16007168 bytesDatabase mounted.
SQL> alter database noarchivelog;Database altered.

SQL> archive log list;Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     228Current log sequence           230SQL>