Oracle 11g，开启archive log模式

在Oracle 11g，开启archive log模式时，默认归档目录为db_recovery_file_dest指定。此参数在pfile/spfile中可以指定：

db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'

 

更改归档模式

需要在mount状态下，更改归档模式。

 

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup mount

ORACLE instance started.

 

Total System Global Area 1258291200 bytes

Fixed Size 1219160 bytes

Variable Size 318768552 bytes

Database Buffers 922746880 bytes

Redo Buffers 15556608 bytes

Database mounted.

 

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 USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence 15

Next log sequence to archive 17

Current log sequence 17

 

更改log_archive_dest_1参数可更改归档日志目录（pfile/spfile中参数db_recovery_file_dest指定的目录将无效）

 

 SQL>
alter system set
log_archive_dest_1='location=/data/oracle/log1/archive_log';     最后的目录名称需要为archive_log?????????????????????????????????????

System altered.

 

SQL> archive log list;

Database log mode             
Archive Mode

Automatic archival            
Enabled

Archive destination           
/data/oracle/log1/archive_log

Oldest online log sequence    
26

Next log sequence to archive  
28

Current log sequence          
28

 

实际上从Oracle
10g开始，可以生成多份一样的日志，保存多个位置，以防不测，方法如下：

SQL>alter system set
log_archive_dest_2='location=/data/oracle/log2/archive_log';

 

SQL> archive log list;

Database log mode             
Archive Mode

Automatic archival            
4000
Enabled

Archive
destination           /data/oracle/log2/archive_log                         只能看到最新设置的归档目录。

Oldest online log sequence    
30

Next log sequence to archive  
32

Current log sequence          
32

 

SQL> alter system archive log current;

 

System altered.

 

SQL> select name from v$archived_log;

 

NAME

--------------------------------------------------------------------------------

/data/oracle/log1/archive_log1_6637_737857592.dbf

/data/oracle/log2/archive_log1_6637_737857592.dbf

 

2rows
selected.

 

将log_archive_log设置为默认值时，归档目录将会变为?/dbs/arch。

SQL> alter system set log_archive_dest_1='';

 

System altered.

 

SQL> alter system set log_archive_dest_2=''

 
2 
;                                                                   ;号最后敲入按回车

 

System altered.

 

SQL> archive log list;

Database log mode             
Archive Mode

Automatic archival            
Enabled

Archive destination           ?/dbs/arch

Oldest online log sequence    
33

Next log sequence to archive  
35

Current log sequence          
35

SQL> shutdown immediat

 

重启数据库后，归档目录变回为db_recovery_file_dest指定的目录。

SQL> archive log list;

Database log mode             
Archive Mode

Automatic archival            
Enabled

Archive destination           
USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence    
33

Next log sequence to archive  
35

Current log sequence          
35

 

 

修改日志文件命名格式：

SQL> alter system set log_archive_max_processes =
5;

SQL> alter system set log_archive_format =
"archive_%t_%s_%r.log" scope=spfile;

 *****************************************************************************************************************

 SQL>archive log list;
如果显示为ENABLE则表示已成功归档
或 SQL>select log_mode
from v$database;
如果为ARCHIVELOG则表示已成功归档

********************************************************************************

SQL> show parameter
db_recovery　　

　　NAME                                  
 
 TYPE      
                
  VALUE

------------------------------------      
  -----------                    
  ------------------------------

db_recovery_file_dest                
 
string                    
  /data/oracle/flash_recovery_area

db_recovery_file_dest_size     
   big
integer                  4231m

　　可以修改db_recovery_file_dest_size参数的大小

　　SQL>alter system set
db_recovery_file_dest_size=21474836480