Add redo log group and add log group diversification
View the status of redo log groups and the location of logs.
SQL > select * from v$log
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARCSTATUS FIRST_CHANGE#FIRST_TIME NEXT_CHANGE# NEXT_TIME
1 1 10 52428800 512 1YES INACTIVE 102400224-NOV-15 1026535 24-NOV-15
2 1 11 52428800 512 1YES ACTIVE 102653524-NOV-15 1039876 27-NOV-15
3 1 12 52428800 512 1NO CURRENT 1039876 27-NOV-15 2.8147E+14
SQL > col memberfor A50
SQL > select * from v$logfile
GROUP# STATUS TYPE MEMBER IS_
3 ONLINE / u01/apps/oracle/oradata/orcl/redo03.log NO
2 ONLINE / u01/apps/oracle/oradata/orcl/redo02.log NO
1 ONLINE / u01/apps/oracle/oradata/orcl/redo01.log NO
Establish the path where the system will store log groups.
SQL >! mkdir-p/u01/apps/oracle/oradata/orcl/redo
SQL > alter database add logfile group4 ('/ u01ax size size 50m)
Database altered.
Establish diversity for each redo log group.
SQL > alter database add logfilemember'/ u01qappsUniplicateoracle.oradataUniplicationorclPlanceRedoLog'to group 1
Databasealtered.
SQL > alter database add logfilemember'/ u01 to group to group 2
Databasealtered.
SQL > alter database add logfilemember'/ u01 to group to group 3
Databasealtered.
SQL > alter database add logfilemember'/ u01 to group to group 4
Databasealtered.
Check the status of redo, combination 4 is not used, so cut the log several times, combination 4 has taken effect.
SQL > select * from v$log
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARCSTATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
-
1 1 10 52428800 512 2YES INACTIVE 102400224-NOV-15 1026535 24-NOV-15
2 1 11 52428800 512 2YES INACTIVE 102653524-NOV-15 1039876 27-NOV-15
3 1 12 52428800 512 2NO CURRENT 103987627-NOV-15 2.8147E+14
4 1 0 52428800 512 2YES UNUSED 00
SQL > select * fromv$logfile
GROUP# STATUS TYPE MEMBER IS_
3 ONLINE / u01/apps/oracle/oradata/orcl/redo03.log NO
2 ONLINE / u01/apps/oracle/oradata/orcl/redo02.log NO
1 ONLINE / u01/apps/oracle/oradata/orcl/redo01.log NO
4 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo04.log NO
1 INVALID ONLINE / u01/apps/oracle/oradata/orcl/redo/redo011.log NO
2 INVALID ONLINE / u01/apps/oracle/oradata/orcl/redo/redo022.log NO
3 INVALID ONLINE / u01/apps/oracle/oradata/orcl/redo/redo033.log NO
4 INVALID ONLINE / u01/apps/oracle/oradata/orcl/redo/redo044.log NO
SQL > alter systemswitch logfile
Systemaltered.
SQL > /
Systemaltered.
SQL > /
Systemaltered.
SQL > /
Systemaltered.
View log group diversity
SQL > select * fromv$log
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARCSTATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
-
1 1 14 52428800 512 2YES INACTIVE 104102627-NOV-15 1041029 27-NOV-15
2 1 15 52428800 512 2YES INACTIVE 104102927-NOV-15 1041037 27-NOV-15
3 1 16 52428800 512 2NO CURRENT 104103727-NOV-15 2.8147E+14
41 13 52428800 512 2YES INACTIVE 104100727-NOV-15 1041026 27-NOV-15
SQL > select * fromv$logfile
GROUP# STATUS TYPE MEMBER IS_
3 ONLINE / u01/apps/oracle/oradata/orcl/redo03.log NO
2 ONLINE / u01/apps/oracle/oradata/orcl/redo02.log NO
1 ONLINE / u01/apps/oracle/oradata/orcl/redo01.log NO
4 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo04.log NO
1 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo011.log NO
2 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo022.log NO
3 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo033.log NO
4 ONLINE / u01/apps/oracle/oradata/orcl/redo/redo044.log NO
