Redo log 的添加与删除
1 查看redo 信息
SQL> select group#,type, member from v$logfile;
GROUP# TYPE MEMBER
---------- ------- -------------------------------------------------------------
3 ONLINE /u01/app/oracle/oradata/xezf/redo03.log
2 ONLINE /u01/app/oracle/oradata/xezf/redo02.log
1 ONLINE /u01/app/oracle/oradata/xezf/redo01.log
4 STANDBY /u01/app/oracle/oradata/xezf/redo04.log
5 STANDBY /u01/app/oracle/oradata/xezf/redo05.log
6 STANDBY /u01/app/oracle/oradata/xezf/redo06.log
7 STANDBY /u01/app/oracle/oradata/xezf/redo07.log
7 rows selected.
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 YES INACTIVE 50
2 1 NO CURRENT 50
3 1 YES INACTIVE 50
2 修改standby redo
SQL> alter database drop logfile group 4;
Database altered.
SQL> alter database drop logfile group 5;
Database altered.
SQL> alter database drop logfile group 6;
Database altered.
SQL> alter database drop logfile group 7;
Database altered.
SQL> select group#,type, member from v$logfile;
GROUP# TYPE MEMBER
---------- ------- -------------------------------------------------------------
3 ONLINE /u01/app/oracle/oradata/xezf/redo03.log
2 ONLINE /u01/app/oracle/oradata/xezf/redo02.log
1 ONLINE /u01/app/oracle/oradata/xezf/redo01.log
添加standby redo
SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 4 ('/u01/app/oracle/oradata/xezf/std_redo04.log') size 100M;
Database altered.
SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 5 ('/u01/app/oracle/oradata/xezf/std_redo05.log') size 100M;
Database altered.
SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 6 ('/u01/app/oracle/oradata/xezf/std_redo06.log') size 100M;
Database altered.
SQL> ALTER DATABASE ADD STANDBY LOGFILE GROUP 7 ('/u01/app/oracle/oradata/xezf/std_redo07.log') size 100M;
Database altered.
SQL> select group#,type, member from v$logfile;
GROUP# TYPE MEMBER
---------- ------- -------------------------------------------------------------
3 ONLINE /u01/app/oracle/oradata/xezf/redo03.log
2 ONLINE /u01/app/oracle/oradata/xezf/redo02.log
1 ONLINE /u01/app/oracle/oradata/xezf/redo01.log
4 STANDBY /u01/app/oracle/oradata/xezf/std_redo04.log
5 STANDBY /u01/app/oracle/oradata/xezf/std_redo05.log
6 STANDBY /u01/app/oracle/oradata/xezf/std_redo06.log
7 STANDBY /u01/app/oracle/oradata/xezf/std_redo07.log
7 rows selected.
3 修改Online redo
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 YES INACTIVE 50
2 1 NO CURRENT 50
3 1 YES INACTIVE 50
先处理inactive， 它表示已经完成规定的，可以删除。
SQL> alter database drop logfile group 1;
Database altered.
SQL> alter database drop logfile group 3;
alter database drop logfile group 3
*
ERROR at line 1:
ORA-01567: dropping log 3 would leave less than 2 log files for instance xezf
(thread 1)
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/xezf/redo03.log'
-- 至少要2个redo组，看来还是只能慢慢来了。
SQL> alter database add logfile group 1 ('/u01/app/oracle/oradata/xezf/redo01.log') size 100M;
alter database add logfile group 1 ('/u01/app/oracle/oradata/xezf/redo01.log') size 100M
*
ERROR at line 1:
ORA-00301: error in adding log file '/u01/app/oracle/oradata/xezf/redo01.log' -
file cannot be created
ORA-27038: created file already exists
Additional information: 1
-- 物理文件没有删除，手工的把物理文件删除后，在创建：
SQL> alter database add logfile group 1 ('/u01/app/oracle/oradata/xezf/redo01.log') size 100M;
Database altered.
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 YES UNUSED 100
2 1 NO CURRENT 50
3 1 YES INACTIVE 50
group1 搞定了。
SQL> alter database drop logfile group 3;
Database altered.
删除对应的物理文件，在添加
SQL> alter database add logfile group 3 ('/u01/app/oracle/oradata/xezf/redo03.log') size 100M;
Database altered.
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 YES UNUSED 100
2 1 NO CURRENT 50
3 1 YES UNUSED 100
group3 搞定。
切换一下logfile，在删除group2
SQL> alter system switch logfile;
System altered.
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 NO CURRENT 100
2 1 YES ACTIVE 50
-- group 正在归档，我们等会在看一下
3 1 YES UNUSED 100
几分钟之后：
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 NO CURRENT 100
2 1 YES INACTIVE 50
3 1 YES UNUSED 100
SQL> alter database drop logfile group 2;
Database altered.
删除物理文件，在创建
SQL> alter database add logfile group 2 ('/u01/app/oracle/oradata/xezf/redo02.log') size 100M;
Database altered.
SQL> select group#,thread#,archived,status, bytes/1024/1024 from v$log;
GROUP# THREAD# ARC STATUS BYTES/1024/1024
---------- ---------- --- ---------------- ---------------
1 1 NO CURRENT 100
2 1 YES UNUSED 100
3 1 YES UNUSED 100
搞定。