1、查看当前数据库的归档模式
（1）使用archive log list命令
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u010g/oradata/test/arch
Oldest online log sequence 373
Next log sequence to archive 375
Current log sequence 375
SQL>

（2）查询视图v$database:
SQL> select log_mode from v$database;

LOG_MODE
------------
ARCHIVELOG

SQL>

2、修改数据库的归档模式
·从非归档模式切换到归档模式
（1）以sysdba用户连接到数据库
（2）关闭数据库
（3）以mount模式打开数据库
（4）将数据库修改为归档模式
（5）打开数据库
eg：
SQL> conn /as sysdba
Connected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.

Total System Global Area 184549376 bytes
Fixed Size 1218412 bytes
Variable Size 88082580 bytes
Database Buffers 92274688 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL>

·从归档模式切换到非归档模式
（1）以sysdba用户连接到数据库
（2）关闭数据库
（3）以mount模式打开数据库
（4）将数据库修改为非归档模式
（5）打开数据库
eg：
SQL> conn /as sysdba
Connected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 184549376 bytes
Fixed Size 1218412 bytes
Variable Size 88082580 bytes
Database Buffers 92274688 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> alter database noarchivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL>