Oracle數據庫可以運行在2種模式下:歸檔模式(archivelog)和非歸檔模式(noarchivelog)

歸檔模式可以提高Oracle數據庫的可恢復性，生產數據庫都應該運行在此模式下，歸檔模式應該和相應的備份策略相結合，只有歸檔模式沒有相應的備份策略只會帶來麻煩。

本文簡單介紹如何啟用和關閉數據庫的歸檔模式。

1.shutdown normal或shutdown immediate關閉數據庫

[oracle@jumper oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.4.0 - Production on Sat Oct 15 15:48:36 2005

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to:

Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production

With the Partitioning option

JServer Release 9.2.0.4.0 - Production

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

2.啟動數據庫到mount狀態

SQL> startup mount;

ORACLE instance started.

Total System Global Area  101782828 bytes

Fixed Size                   451884 bytes

Variable Size              37748736 bytes

Database Buffers           62914560 bytes

Redo Buffers                 667648 bytes

Database mounted.

3.啟用或停止歸檔模式

如果要啟用歸檔模式，此處使用

alter database archivelog 命令。

SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> archive log list;

Database log mode              Archive Mode

Automatic archival             Enabled

Archive destination            /opt/oracle/oradata/conner/archive

Oldest online log sequence     148

Next log sequence to archive   151

alter database noarchivelog 命令。

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount;

ORACLE instance started.

Total System Global Area  101782828 bytes

Fixed Size                   451884 bytes

Variable Size              37748736 bytes

Database Buffers           62914560 bytes

Redo Buffers                 667648 bytes

Database mounted.

SQL> alter database noarchivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> archive log list;

Database log mode              No Archive Mode

Automatic archival             Enabled

Archive destination            /opt/oracle/oradata/conner/archive

Oldest online log sequence     149

Current log sequence           152

4.修改相應的初始化參數

Oracle10g之前，你還需要修改初始化參數使數據庫處于自動歸檔模式。

在pfile/spfile中設置如下參數：

log_archive_start = true

重啟數據庫此參數生效，此時數據庫處于自動歸檔模式。

也可以在數據庫啟動過程中，手工執行：

archive log start

使數據庫啟用自動歸檔，但是重啟后數據庫仍然處于手工歸檔模式。