How to add redo log groups and redo log members for oracle
This article focuses on "how to add redo log group and redo log members to oracle". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how to add redo log group and redo log members to oracle.
Add a redo log group:
SYS@orcl 08-SEP-14 > select group#,type,member from v$logfile
GROUP# TYPE MEMBER
-
3 ONLINE / u01/app/oracle/oradata/orcl/redo03.log
2 ONLINE / u01/app/oracle/oradata/orcl/redo02.log
1 ONLINE / u01/app/oracle/oradata/orcl/redo01.log
SYS@orcl 08-SEP-14 > alter database add logfile group 4
2 ('/ u01Accord oradata redo04.log')
3 size 50m
SYS@orcl 08-SEP-14 > select group#,sequence#,bytes/1024/1024 | | 'MB',status from v$log
GROUP# SEQUENCE# BYTES/1024/1024 | | 'MB' STATUS
-
1 25 50MB CURRENT
2 23 50MB INACTIVE
3 24 50MB INACTIVE
4 0 50MB UNUSED
Add a member to the log group:
SYS@orcl 09-SEP-14 > select group#,status,member from v$logfile
GROUP# STATUS MEMBER
-
3 / u01/app/oracle/oradata/orcl/redo03.log
2 / u01/app/oracle/oradata/orcl/redo02.log
1/ u01/app/oracle/oradata/orcl/redo01.log
4 / u01/app/oracle/oradata/orcl/redo04.log
SYS@orcl 09-SEP-14 > alter database add logfile member
2'/ u01qappandredologandredo01a.log' to group 1
3'/ u01 to group to group 2
4'/ u01 to group to group 3
5'/ u01 to group to group 4
Database altered.
SYS@orcl 09-SEP-14 > select group#,status,member,type from v$logfile
GROUP# STATUS MEMBER TYPE
-
3 / u01/app/oracle/oradata/orcl/redo03.log ONLINE
2 / u01/app/oracle/oradata/orcl/redo02.log ONLINE
1/ u01/app/oracle/oradata/orcl/redo01.log ONLINE
4 / u01/app/oracle/oradata/orcl/redo04.log ONLINE
1 INVALID / u01/app/redolog/redo01a.log ONLINE
2 INVALID / u01/app/redolog/redo02a.log ONLINE
3 INVALID / u01/app/redolog/redo03a.log ONLINE
4 INVALID / u01/app/redolog/redo04a.log ONLINE
8 rows selected.
After switching logs four times, the log group member with the status of invalid becomes null.
SYS@orcl 09-SEP-14 > select group#,status,member,type from v$logfile
GROUP# STATUS MEMBER TYPE
-
3 / u01/app/oracle/oradata/orcl/redo03.log ONLINE
2 / u01/app/oracle/oradata/orcl/redo02.log ONLINE
1/ u01/app/oracle/oradata/orcl/redo01.log ONLINE
4 / u01/app/oracle/oradata/orcl/redo04.log ONLINE
1/ u01/app/redolog/redo01a.log ONLINE
2 / u01/app/redolog/redo02a.log ONLINE
3 / u01/app/redolog/redo03a.log ONLINE
4 / u01/app/redolog/redo04a.log ONLINE
8 rows selected.
Delete log group members: (note that if there is only one member in this group, it cannot be deleted)
SYS@orcl 09-SEP-14 > alter database drop logfile member
2'/ u01qappandredologandredo01a.log'
3'/ u01qappActionRedologAccording to redo02a.log'
4'/ u01qappandredologandredo03a.log'
5'/ u01qappActionRedologUnique redo04a.log'
Alter database drop logfile member
*
ERROR at line 1:
ORA-01609: log 1 is the current log for thread 1-cannot drop members
ORA-00312: online log 1 thread 1:'/ u01 Grey App Grease oradata Universe oradata Greater redo01 log'
ORA-00312: online log 1 thread 1:'/ u01ActionApp RedologUnique redo01a.log'
You can see that the redo log being used by the instance cannot be deleted, so we first delete the members of other groups:
SYS@orcl 09-SEP-14 > alter database drop logfile member
2'/ u01qappandredologandredo02a.log'
3'/ u01qappActionRedologAccording to redo03a.log'
4'/ u01qappActionRedologAccording to redo04a.log'
Database altered.
Next, let's switch logs:
SYS@orcl 09-SEP-14 > select group#,sequence#,status from v$log
GROUP# SEQUENCE# STATUS
1 29 CURRENT
2 27 INACTIVE
3 28 INACTIVE
4 26 INACTIVE
SYS@orcl 09-SEP-14 > alter system switch logfile
System altered.
SYS@orcl 09-SEP-14 > select group#,sequence#,status from v$log
GROUP# SEQUENCE# STATUS
1 29 ACTIVE
2 27 INACTIVE
3 28 INACTIVE
4 30 CURRENT
Then delete redo01a.log, a member of log group 1:
SYS@orcl 09-SEP-14 > alter database drop logfile member
2'/ u01qappandredologandredo01a.log'
Database altered.
View log group and log group member information:
SYS@orcl 09-SEP-14 > select group#,status,type,member from v$logfile
GROUP# STATUS TYPE MEMBER
3 ONLINE / u01/app/oracle/oradata/orcl/redo03.log
2 ONLINE / u01/app/oracle/oradata/orcl/redo02.log
1 ONLINE / u01/app/oracle/oradata/orcl/redo01.log
4 ONLINE / u01/app/oracle/oradata/orcl/redo04.log
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