Oracle归档日志文件(查看、配置、删除)
作者:multis
1、概念
归档是将联机重做日志以文件的形式保存到硬盘,联机日志归档的前提条件是数据库要处于归档模式。当数据库处于 ARCHIVELOG 模式并进行日志切换时,后台进程 ARCH 会将联机重做日志的内容保存到归档日志中,当数据库出现介质故障时,使用数据文件备份、归档日志和联机重做日志可以完全恢复数据库到正常状态。
Oracle 数据库设置为归档模式之后,如果归档空间写满,数据库的 redo 文件不能归档,会出现数据库挂起的问题,导致 数据库无法使用。
2、查看数据库是否为归档模式
SQL> archive log list;Database log mode Archive ModeAutomatic archival EnabledArchive destination /app/archiveOldest online log sequence 30Next log sequence to archive 34Current log sequence 34SQL> select log_mode from v$database;LOG_MODE------------------------------------ARCHIVELOG
3、打开或关闭归档模式
如果需要打开或关闭归档模式,在数据库处于 mount 状态时使用如下命令:
3.1 打开归档模式
alter database archivelog;
3.2 关闭归档模式
alter database noarchivelog;
4、配置归档的位置
当数据库处于归档模式时,进行日志切换时后台进程将自动生成归档日志。
4.1 查看归档进程数
初始化参数 LOG_ARCHIVE_MAX_PROCESSES 用于指定最大归档进程个数。通过改变该初始化参数的取值,可以动态地增加或减少归档进程的个数。
SQL> show parameter LOG_ARCHIVE_MAX_PROCESSES; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_max_processes integer 4
4.2 配置归档的位置
可以使用 LOG_ARCHIVE_DEST_n 配置多个归档位置:该参数最多可以指定 10 个归档位置。格式如下:
ALTER SYSTEM SET log_archive_dest_1 = 'location = 路径1'; ALTER SYSTEM SET log_archive_dest_2 = 'location = 路径2'; .....
4.2.1 查看归档文件
SQL> select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- -------------------------------------------------------------------------------- 34 /app/archive/orcl_62725153_0000000034_1_1125947150.dbf
可知归档的文件位置 /app/archive/
4.2.2 修改归档日志的位置为:/home/oracle/archivelog
SQL> alter system set log_archive_dest_1 = 'location=/app/archive' scope = both sid='*'; SQL> archive log list; SQL> alter system switch logfile; SQL> select sequence#, name from v$archived_log; SQL> select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- -------------------------------------------------------------------------------- 34 /app/archive/orcl_62725153_0000000034_1_1125947150.dbf 35 /app/archive/orcl_62725153_0000000035_1_1125947150.dbf
5、配置归档日志文件的名称格式
初始化参数 LOG_ARCHIVE_FORMAT 用于指定归档日志文件的名称格式。设置该初始化参数时,可以指定以下匹配符:
(1)%s:日志序列号;
(2)%S:日志序列号(带有前导 0);
(3)%t:线程编号;
(4)%T:线程编号(带有前导 0);
(5)%a:活动 ID 号;
(6)%d:数据库 ID 号;
(7)%r:RESETLOGS的ID值。
归档日志的文件名称格式设置如下:
SQL> alter system set LOG_ARCHIVE_FORMAT = 'orcl_%d_%S_%t_%r.dbf' scope = spfile sid='*';
重启数据库使设置生效
SQL> shutdown immediate SQL> startup
查看参数 LOG_ARCHIVE_FORMAT 的值:
SQL> show parameter LOG_ARCHIVE_FORMAT NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_format string orcl_%d_%S_%t_%r.dbf
查看归档日志:
SQL> select sequence#, name from v$archived_log;
6、删除归档日志
6.1 手工删除归档日志文件
[oracle@node1 archive]$ cd /app/archive/ [oracle@node1 archive]$ ll -r 总用量 4516 -rw-r----- 1 oracle oinstall 10752 2月 2 10:54 orcl_62725153_0000000036_1_1125947150.dbf -rw-r----- 1 oracle oinstall 54784 2月 2 10:51 orcl_62725153_0000000035_1_1125947150.dbf -rw-r----- 1 oracle oinstall 4551680 2月 2 10:46 orcl_62725153_0000000034_1_1125947150.dbf [oracle@node1 archive]$ rm -rf orcl_62725153_0000000034_1_1125947150.dbf [oracle@node1 archive]$ ll 总用量 68 -rw-r----- 1 oracle oinstall 54784 2月 2 10:51 orcl_62725153_0000000035_1_1125947150.dbf -rw-r----- 1 oracle oinstall 10752 2月 2 10:54 orcl_62725153_0000000036_1_1125947150.dbf
查看归档日志:
SQL> select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- -------------------------------------------------------------------------------- 34 /app/archive/orcl_62725153_0000000034_1_1125947150.dbf 35 /app/archive/orcl_62725153_0000000035_1_1125947150.dbf 36 /app/archive/orcl_62725153_0000000036_1_1125947150.dbf
虽然物理文件已经删除,但是归档日志文件的信息还在。
6.2 用 RMAN 删除数据库记录的归档列表信息
[oracle@node1 ~]$ rman target / RMAN> list archivelog all; List of Archived Log Copies for database with db_unique_name ORCL ===================================================================== Key Thrd Seq S Low Time ------- ---- ------- - --------- 36 1 34 X 02-FEB-23 Name: /app/archive/orcl_62725153_0000000034_1_1125947150.dbf 37 1 35 A 02-FEB-23 Name: /app/archive/orcl_62725153_0000000035_1_1125947150.dbf 38 1 36 A 02-FEB-23 Name: /app/archive/orcl_62725153_0000000036_1_1125947150.dbf RMAN> crosscheck archivelog all; released channel: ORA_DISK_1 allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=1996 device type=DISK validation failed for archived log archived log file name=/app/archive/orcl_62725153_0000000034_1_1125947150.dbf RECID=36 STAMP=1127731566 validation succeeded for archived log archived log file name=/app/archive/orcl_62725153_0000000035_1_1125947150.dbf RECID=37 STAMP=1127731881 validation succeeded for archived log archived log file name=/app/archive/orcl_62725153_0000000036_1_1125947150.dbf RECID=38 STAMP=1127732067 Crosschecked 3 objects RMAN> delete expired archivelog all; released channel: ORA_DISK_1 allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=1996 device type=DISK List of Archived Log Copies for database with db_unique_name ORCL ===================================================================== Key Thrd Seq S Low Time ------- ---- ------- - --------- 36 1 34 X 02-FEB-23 Name: /app/archive/orcl_62725153_0000000034_1_1125947150.dbf Do you really want to delete the above objects (enter YES or NO)? yes deleted archived log archived log file name=/app/archive/orcl_62725153_0000000034_1_1125947150.dbf RECID=36 STAMP=1127731566 Deleted 1 EXPIRED objects RMAN> select sequence#, name from v$archived_log;select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- -------------------------------------------------------------------------------- 34 35 /app/archive/orcl_62725153_0000000035_1_1125947150.dbf 36 /app/archive/orcl_62725153_0000000036_1_1125947150.dbf
6.3 清除 v$archived_log 视图中的过期信息
使用 RMAN 命令删除归档后,v$archived_log 视图中的 name 列为空,但其他列的信息仍然存在。出现这种现象的原因是因为使用 RMAN 命令在删除归档日志的时候不能够清除控制文件中的内容。
6.3.1 清除控制文件中关于 v$archived_log 的信息
SQL> execute sys.dbms_backup_restore.resetCfileSection(11); PL/SQL procedure successfully completed.
6.3.2 查询发现 v$archived_log 视图中的信息全部被清除了
SQL> select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- --------------------------------------------------------------------------------
6.3.3 将未过期的归档文件信息重新注册到控制文件中
RMAN> catalog start with '/app/archive/'; using target database control file instead of recovery catalog searching for all files that match the pattern /app/archive/ List of Files Unknown to the Database ===================================== File Name: /app/archive/orcl_62725153_0000000035_1_1125947150.dbf File Name: /app/archive/orcl_62725153_0000000036_1_1125947150.dbf Do you really want to catalog the above files (enter YES or NO)? yes cataloging files... cataloging done List of Cataloged Files ======================= File Name: /app/archive/orcl_62725153_0000000035_1_1125947150.dbf File Name: /app/archive/orcl_62725153_0000000036_1_1125947150.dbf RMAN> select sequence#, name from v$archived_log; SEQUENCE# NAME ---------- -------------------------------------------------------------------------------- 35 /app/archive/orcl_62725153_0000000035_1_1125947150.dbf 36 /app/archive/orcl_62725153_0000000036_1_1125947150.dbf
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