oracle启用归档日志

Posted 2020-11-10 sorliran

1、查看归档信息

SQL> archive log list
Database log mode           No Archive Mode
Automatic archival           Disabled
Archive destination           USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     244
Current log sequence           246

 

当前数据库未开启归档

2、设置归档目录

oracle默认使用闪回恢复区DB_RECOVERY_FILE_DEST作为归档路径

SQL> show parameter DB_RECOVERY_FILE_DEST

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest             string     /u01/app/oracle/flash_recovery_area
db_recovery_file_dest_size         big integer 3882M

 

闪回恢复区在安装过程中有限制其大小，如果闪回恢复区满了，归档日志会无法写入而导致数据库hang住，解决办法可以增加闪回区大小或者修改归档路径

3、修改归档路径

修改log_archive_dest_1参数可修改归档日志路径（pfile/spfile中参数db_recovery_file_dest指定的目录将无效）

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。多个位置通过设置不同的log_archive_dest_n 参数实现，archive log list输出中的Archive destination路径只显示最新修改的路径。

SQL> show parameter log_archive_dest_1

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_1             string
log_archive_dest_10             string
log_archive_dest_11             string
log_archive_dest_12             string
log_archive_dest_13             string
log_archive_dest_14             string
log_archive_dest_15             string
log_archive_dest_16             string
log_archive_dest_17             string
log_archive_dest_18             string
log_archive_dest_19             string

 

修改归档路径为/u01/app/oracle/archive_log

SQL> alter system set log_archive_dest_1=‘location=/u01/app/oracle/archive_log‘ scope=spfile;

System altered.

 

重启生效

4、修改归档日志格式

SQL> alter system set log_archive_format=‘ARC%S_%R.%T_%D.dbf‘ scope=spfile;

System altered.

 

重启生效

5、开启归档

需要在mount状态下开启数据库归档

重启至mount

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

Total System Global Area 1603411968 bytes
Fixed Size            2213776 bytes
Variable Size          989857904 bytes
Database Buffers      603979776 bytes
Redo Buffers            7360512 bytes
Database mounted.

 

开启数据库归档

SQL> alter database archivelog;

Database altered.

 

查看归档情况

SQL> archive log list
Database log mode           Archive Mode
Automatic archival           Enabled
Archive destination           /u01/app/oracle/archive_log
Oldest online log sequence     244
Next log sequence to archive   246
Current log sequence           246

 

ALTER DATABASE FORCE LOGGING;
开启强制归档

打开数据库

SQL> alter database open;

Database altered.

 

6、确认数据库为归档模式

SQL> select log_mode from v$database;

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

SQL> select archiver from v$instance;

ARCHIVE
-------
STARTED

 

7、强制日志切换

先查看当前归档日志视图和归档日志路径：

SQL> select name from v$archived_log;

no rows selected

[[email protected] archive_log]$ ll
total 0

 

没有归档日志

下面执行强制日志切换

SQL> alter system switch logfile;

System altered.

 

再次查看视图

SQL> select name from v$archived_log;

NAME
--------------------------------------------------------------------------------
/u01/app/oracle/archive_log/ARC0000000246_0963417259.0001_6833bc69.dbf

 

有归档日志产生，验证成功

 

//TODO

RMAN归档日志清理