1. 用sys用户登录
sqlplus sys/pass@tt as sysdba
2. 看看archiv log所在位置
SQL> show parameter log_archive_dest;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest string
log_archive_dest_1 string
log_archive_dest_10 string
3. 一般VALUE为空时，可以用archive log list;检查一下归档目录和log sequence
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 360
Next log sequence to archive 360
Current log sequence 362
4. 检查flash recovery area的使用情况,可以看见archivelog已经很大了，达到96.62
SQL> select * from V$FLASH_RECOVERY_AREA_USAGE;
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .13 0 1
ONLINELOG 2.93 0 3
ARCHIVELOG 96.62 0 141
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG 0 0 0
5. 计算flash recovery area已经占用的空间
SQL> select sum(percent_space_used)*3/100 from v$flash_recovery_area_usage;
SUM(PERCENT_SPACE_USED)*3/100
-----------------------------
2.9904
6. 找到recovery目录, show parameter recover
SQL> show parameter recover;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /u01/app/oracle/flash_recovery_area
db_recovery_file_dest_size big integer 5G
recovery_parallelism integer 0
7 上述结果告诉我们，归档位置用的是默认值，放在flash_recovery_area下(db_recovery_file_dest目录=/u01/app/oracle/flash_recovery_area)
[root@sha3 10.2.0]# echo $ORACLE_BASE
/u01/app/oracle
[root@sha3 10.2.0]# cd $ORACLE_BASE/flash_recovery_area/tt/archivelog
转移或清除对应的归档日志, 删除一些不用的日期目录的文件，注意保留最后几个文件（比如360以后的）
---------------------------------------------------------------------------------------
注意:
在删除归档日志后，必须用RMAN维护控制文件，否则空间显示仍然不释放。
---------------------------------------------------------------------------------------
8. rman target sys/pass
[root@sha3 oracle]# rman target sys/pass
Recovery Manager: Release 10.2.0.4.0 - Production on Tue Jan 20 01:41:26 2009
Copyright (c) 1982, 2007, Oracle. All rights reserved.
connected to target database: tt (DBID=4147983671)
9. 检查一些无用的archivelog
RMAN> crosscheck archivelog all;
10. 删除过期的归档
RMAN> delete expired archivelog all;
delete archivelog until time 'sysdate-1' ; 删除截止到前一天的所有archivelog
11. 再次查询，发现使用率正常，已经降到23.03
SQL> select * from V$FLASH_RECOVERY_AREA_USAGE;
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .13 0 1
ONLINELOG 2.93 0 3
ARCHIVELOG 23.03 0 36
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG 0 0 0
其它有用的Command:
----------------------------------
如果archive log模式下不能正常startup,则先恢复成noarchive log,startup成功后，再shutdown;
shutdown immediate;
startup mount;
alter database noarchivelog;
alter database open;
shutdown immediate;
再次startup以archive log模式
shutdown immediate;
startup mount;
show parameter log_archive_dest;
alter database archivelog;
archive log list;
alter database open;
如果还不行，则删除一些archlog log
SQL> select group#,sequence# from v$log;
GROUP# SEQUENCE#
---------- ----------
1 62
3 64
2 63
原来是日志组一的一个日志不能归档
SQL> alter database clear unarchived logfile group 1;
alter database open;
最后，也可以指定位置Arch Log, 请按照如下配置
select name from v$datafile;
alter system set log_archive_dest='/opt/app/oracle/oradata/usagedb/arch' scope=spfile
或者修改大小
SQL> alter system set db_recovery_file_dest_size=3G scope=both;