oracle启用归档日志

一、开启归档

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

[oracle@zml-rhel6 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

二、归档日志清理

1、手动物理删除归档日志

该方式利用linux的命令find查找N天以前的日志，直接删除

[oracle@localhost archive_log]$ find . -type f -mtime +2.4 -print |xargs ls -rlt
-rw-r----- 1 oracle oinstall 16092672 6月   4 20:45 ./ARC0000000606_0977259429.0001_fb0ffee2.dbf
-rw-r----- 1 oracle oinstall 38390272 6月   4 22:00 ./ARC0000000607_0977259429.0001_fb0ffee2.dbf
-rw-r----- 1 oracle oinstall 32950272 6月   4 22:02 ./ARC0000000608_0977259429.0001_fb0ffee2.dbf

该例子中查询到2.4天前日志列表。手工物理删除这些日志文件：

[oracle@localhost archive_log]$ find . -type f -mtime +2.4 -print |xargs rm -f

虽然手工删除的了归档日志文件，但是控制文件中依然会有这些日志的记录，下面需要在控制文件中清理这些归档日志。利用rman：

查看过期日志：

RMAN> list expired archivelog all;

specification does not match any archived log in the repository

返回信息显示没有过期日志，这是因为需要先检查归档日志有效性，再进行删除：

RMAN> crosscheck archivelog all;
....
....
....
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000002400_0977259429.0001_fb0ffee2.dbf RECID=1795 STAMP=978255518
validation succeeded for archived log
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000002401_0977259429.0001_fb0ffee2.dbf RECID=1796 STAMP=978255659
validation succeeded for archived log
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000002402_0977259429.0001_fb0ffee2.dbf RECID=1797 STAMP=978256043
Crosschecked 1797 objects

再次查看过期归档日志，rm删除的三个文件便被标记为了过期日志：

RMAN> list expired archivelog all;

List of Archived Log Copies for database with db_unique_name ORCLWHS
=====================================================================

Key     Thrd Seq     S Low Time 
------- ---- ------- - ---------
1       1    606     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000606_0977259429.0001_fb0ffee2.dbf

2       1    607     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000607_0977259429.0001_fb0ffee2.dbf

3       1    608     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000608_0977259429.0001_fb0ffee2.dbf

删除过期归档日志：

RMAN> delete expired archivelog all;

released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=446 device type=DISK
List of Archived Log Copies for database with db_unique_name ORCLWHS
=====================================================================

Key     Thrd Seq     S Low Time 
------- ---- ------- - ---------
1       1    606     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000606_0977259429.0001_fb0ffee2.dbf

2       1    607     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000607_0977259429.0001_fb0ffee2.dbf

3       1    608     X 04-JUN-18
        Name: /home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000608_0977259429.0001_fb0ffee2.dbf


Do you really want to delete the above objects (enter YES or NO)? yes
deleted archived log
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000606_0977259429.0001_fb0ffee2.dbf RECID=1 STAMP=977949943
deleted archived log
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000607_0977259429.0001_fb0ffee2.dbf RECID=2 STAMP=977954446
deleted archived log
archived log file name=/home/oracle/app/oracle/archive/orclwhs/archive_log/ARC0000000608_0977259429.0001_fb0ffee2.dbf RECID=3 STAMP=977954551
Deleted 3 EXPIRED objects

再次查询过期归档：

RMAN> list expired archivelog all;   

specification does not match any archived log in the repository

2、RMAN归档日志清理

删除归档日志正确的流程：

RMAN> crosscheck archivelog all; //验证的DB的归档日志
RMAN> delete expired archivelog all; //删除所有归档日志
RMAN> DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-7'; //保留7天的归档日志

定时shell脚本

#!/bin/bash
export ORACLE_BASE=/home/oracle/app/oracle
export ORACLE_HOME=/home/oracle/app/oracle/product/11.2.0/dbhome_1
export export ORACLE_SID=orclwhs

${ORACLE_HOME}/bin/rman nocatalog log=/home/oracle/bin/cleararchivelog/del_arch$(date +%Y-%m-%d).log <<EOF  
connect target /  
#crosscheck archivelog all;  
#delete noprompt expired archivelog all;  
DELETE noprompt ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-2';  
exit;  
EOF

可参考：https://blog.csdn.net/javaee_ssh/article/details/36906413