Restore in noarchivelog mode ( redo log files have been dropped )

1, A full backup taken using RMAN is available on disk.
2, The current control files were NOT damaged and do not need to be restored.
3, All data files are damaged .
4, The database is in NOARCHIVELOG mode.
I restore database :
1. RMAN> STARTUP MOUNT
2. RMAN> RESTORE DATABASE;
3. RMAN> recover database;
in this step , I got the information about needing redo log files ; but the redo log
files have been dropped , what should i do ?
else
I want to know there is the command 'recover database using backup control file'
in rman or not ?
Tks

Possibly loss of data (because information in online redo logs is lost):
recover database until cancel;
(cancel immediately)
alter database open resetlogs; (to build a new set of redo logs)
It's not necessary to use a backup controlfile here.

Similar Messages

Commit Completes although current online redo log file have been removed.

Although i have removed current online redo log file in linux os (Oracle Linux),when i type "commit" it says that "commit complete".
Is this fair for this princip?*:" if Only when all redo records associated with a given transaction are safely on disk in the online logs is the user process notified that the transaction has been committed."*
I think that it can lead to loss of data in some cases..I'm using Oracle 11g R2 on OEL (x64)..
Can anyone explain me ? I'm getting stuck in this situation..
P.S : I haven't multiplexed current ORL group files...

Javid wrote:
Although i have removed current online redo log file in linux os (Oracle Linux),when i type "commit" it says that "commit complete".
Is this fair for this princip?*:" if Only when all redo records associated with a given transaction are safely on disk in the online logs is the user process notified that the transaction has been committed."*
I think that it can lead to loss of data in some cases..I'm using Oracle 11g R2 on OEL (x64)..
Can anyone explain me ? I'm getting stuck in this situation..
In *nix, a file that is open by a process isn't really deleted until the process that has it completes. So even though you 'deleted' a redo log, oracle is still holding it. As soon as you stop your database (maybe even as soon as the db does a log switch) the redo will really be gone and no longer available. consider the implications for archive logging.
P.S : I haven't multiplexed current ORL group files...You need to fix that. the online logs are the achilles heel of the database. That's why it is standard practice to multiplex them.

Missing current redo log files

hello to all
i have a question please if you can guide me.
if i lose all current redo log files (current redo log group files) how i can repair it and open
database ? (i don't have problem by missing INACTIVE redo group)
thanks

Hi,
>>if i lose all current redo log files (current redo log group files) how i can repair it and
open database ? (i don't have problem by missing INACTIVE redo group)Well, It depends. The database was active when the current log file was lost ? Are you using RMAN ? The database is operating in ARCHIVELOG mode or NOARCHIVEMOG mode ? Basically, an incomplete recovery is necessary when there is a loss of the current redo log files. It means that you don’t have all the redo log files up to the point of failure, so the only alternative is[b] to recover prior to the point of failure. To perform incomplete recovery after the redo log files have been lost, you do the following (if you are not using RMAN):
1) Execute a SHUTDOWN command and restore all data files (*.dbf) from most recent backup.
2) Execute a STARTUP MOUNT command to read the contents of the control file.
3) Execute a RECOVER DATABASE UNTIL CANCEL command to start the recovery process.
SQL> startup mount;
4) Execute a RECOVER DATABASE UNTIL CANCEL command to start the recovery process.
SQL> recover database until cancel;
5) Apply the necessary archived logs up to, but not including, the lost or corrupted log.
6) Open the database and reset the log files.
SQL> alter database open resetlogs;
7) Shut down the database.
SQL> shutdown normal;
8) Take a full cold backup
In resume, for more information, take a look at [url http://download-west.oracle.com/docs/cd/B19306_01/backup.102/b14191/recoscen008.htm#sthref1872]Recovering After the Loss of Online Redo Log Files: Scenarios
Cheers
Legatti

Use of standby redo log files in primary database

Hi All,
What is the exact use of setting up standby redo log files in the primary database on a data guard setup?
any good documents?

A standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.
You should plan the standby redo log configuration and create all required log groups and group members when you create the standby database. For increased availability, consider multiplexing the standby redo log files, similar to the way that online redo log files are multiplexed.
refer the link,and Perform the following steps to configure the standby redo log.:-
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
If the real-time apply feature is enabled, log apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived. This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins.
refer the link
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/log_apply.htm#i1023371

Reg:Redo log files

Hi,
By mistake the redo log files have been removed.
Hence we tried to create the redo log files.
After creating it when select * from v$log is done, it is as follows
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS
FIRST_CHANGE# FIRST_TIM
1 1 0 1073741824 1 YES UNUSED
0
3 1 0 1073741824 1 YES UNUSED
0
2 1 0 1073741824 1 NO CURRENT
179433372 20-NOV-10
Due to this, whatever alter command we use, it is not working.
For ex.
SQL> alter database open resetlogs;
alter database open resetlogs
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/alcatel/oracle/oradata/SNM/system01.dbf'
SQL> alter database mount;
alter database mount
ERROR at line 1:
ORA-01100: database already mounted
SQL> alter system switch logfile;
alter system switch logfile
ERROR at line 1:
ORA-01109: database not open
SQL> ALTER DATABASE OPEN;
ALTER DATABASE OPEN
ERROR at line 1:
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open
WE want to change the status in v$log table from Current to ACTIVE and UNUSED to INACTIVE.
How can we do that?
Can anyone help us?
Regards
Srini

Hi ,
WE have tried those but in vain..
Please find the error logs
SQL> alter system switch logfile;
alter system switch logfile
ERROR at line 1:
ORA-01109: database not open
SQL> alter database open resetlogs;
alter database open resetlogs
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/alcatel/oracle/oradata/SNM/system01.dbf'
SQL> ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/alcatel/oracle/oradata/SNM/system01.dbf'SP2-0734: unknown command beginning "ORA-01194:..." - rest of line ignored.
SQL> ^C
SQL> recover database until cancel;
ORA-00283: recovery session canceled due to errors
ORA-01610: recovery using the BACKUP CONTROLFILE option must be done
SQL> alter database open resetlogs;
alter database open resetlogs
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/alcatel/oracle/oradata/SNM/system01.dbf'
SQL> recover database until cancel using backup controlfile;
ORA-00279: change 179433372 generated at 11/20/2010 18:00:10 needed for thread
1
ORA-00289: suggestion : /alcatel/oracle/admin/SNM/arch/arch_1_635_666206692.arc
ORA-00280: change 179433372 for thread 1 is in sequence #635
Srini

Need to understand when redo log files content is wrote to datafiles

Hi all
I have a question about the time when redo log files are wrote to the datafiles
supposing that the database is in NOARCHIVELOG mode, and all redo log files are filled, the official oracle database documentation says that: *a filled redo log file is available
after the changes recorded in it have been written to the datafiles* witch mean that we just need to have all the redo log files filled to "*commit*" changes to the database
Thanks for help
Edited by: rachid on Sep 26, 2012 5:05 PM

rachid wrote:
the official oracle database documentation says that: a filled redo log file is available after the changes recorded in it have been written to the datafiles It helps if you include a URL to the page where you found this quote (if you were using the online html manuals).
The wording is poor and should be modified to something like:
<blockquote>
+"a filled online redo log file is available for re-use after all the data blocks that have been changed by change vectors recorded in the log file have been written to the data files"+
</blockquote>
Remember if a data block that is NOT an undo block has been changed by a transaction, then an UNDO block has been changed at the same time, and both change vectors will be in the redo log file. The redo log file cannot, therefore, be re-used until the data block and the associated UNDO block have been written to disc. The change to the data block can thus be rolled back (uncommitted changes can be written to data files) because the UNDO is also available on disc if needed.
If you find the manuals too fragmented to follow you may find that my book, Oracle Core, offers a narrative description that is easier to comprehend.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
Author: <b><em>Oracle Core</em></b>

Problem in creating database -Missing Redo log file

I am try to create a new database using DBCA .While creating a database it shows the error oracle instance terminated.Force Disconnected.
My alert log file is
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/oracl/redo01.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Wed Nov 06 10:07:27 2013
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/oracl/redo02.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/oracl/redo03.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Wed Nov 06 10:07:38 2013
Setting recovery target incarnation to 2
Wed Nov 06 10:07:38 2013
Assigning activation ID 1876274518 (0x6fd5ad56)
Thread 1 opened at log sequence 1
Current log# 1 seq# 1 mem# 0: /u01/app/oracle/oradata/oracl/redo01.log
Successful open of redo thread 1
Wed Nov 06 10:07:38 2013
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Wed Nov 06 10:07:38 2013
SMON: enabling cache recovery
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc (incident=1345):
ORA-00600: internal error code, arguments: [kpotcgah-7], [12534], [ORA-12534: TNS:operation not supported
Incident details in: /u01/app/oracle/diag/rdbms/oracl/oracl/incident/incdir_1345/oracl_ora_5424_i1345.trc
Wed Nov 06 10:07:46 2013
Trace dumping is performing id=[cdmp_20131106100746]
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00600: internal error code, arguments: [kpotcgah-7], [12534], [ORA-12534: TNS:operation not supported
Error 600 happened during db open, shutting down database
USER (ospid: 5424): terminating the instance due to error 600
Instance terminated by USER, pid = 5424
ORA-1092 signalled during: alter database "oracl" open resetlogs...
ORA-1092 : opiodr aborting process unknown ospid (5424_47935551851664)
Wed Nov 06 10:07:47 2013
ORA-1092 : opitsk aborting process
251,1 95%

>I am try to create a new database using DBCA
>Please help me to resolve this issue.My redo log file was missing
DROP and recreate the database. It is a *new* database without any data.
Check what datafile locations and redo log file locations you specify when creating the new database. Check if you have permissions and enough disk space.
Hemant K Chitale

Db restore non archive mode lost redo log file..restore from controlfile tr

i have a db 11g I had taken non archive backup but failed to take redo log files backup...
so while i restored the db ... after formatting the machine ..the oracle instance wont start.
I create a controlfile trace but when i run it i get errors.
since i dont have the older log files.. how do i get around with this issue
Thanks
Following is the sample of control file trace ..Note i cannot create the redo log file
since db wont be mounted at most it shall be in nonmount mode
and below is my created controlfile ....
CREATE CONTROLFILE REUSE DATABASE "XE" NORESETLOGS NOARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_1_80L7C259_.LOG'
SIZE 50M BLOCKSIZE 512,
GROUP 2
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_2_80L7C375_.LOG'
SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\UNDOTBS1.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSAUX.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF'
CHARACTER SET AL32UTF8
I dont have these 2 files ..what do i do to get around this situation
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_1_80L7C259_.LOG'
SIZE 50M BLOCKSIZE 512,
GROUP 2
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_2_80L7C375_.LOG'
SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
Edited by: zycoz100 on Feb 27, 2013 10:57 PM

If you have a cold backup (database shutdown properly) without the redo logs, change this :
CREATE CONTROLFILE REUSE DATABASE "XE" NORESETLOGS NOARCHIVELOGto
CREATE CONTROLFILE REUSE DATABASE "XE" RESETLOGS NOARCHIVELOGYou have to change the NORESETLOGS to RESETLOGS for Oracle to recreate the online redo logs.
Hemant K Chitale

Redo log files in case of NOARCHIVELOG Mode.

Question is related with the oracle architure..
database requires a minimum of two redo log files to guarantee that one is always available for writing while the other is being archived, this sounds perfect when DB is running in ARCHIVELOG mode but at the same time it also forces database to have 2 redo log files even when the DB is running in NOARCHIVELOG mode?
Any particular reason..
I would look for reasons not answers on what redo log is and what information it holds etc..

pgoel wrote:
If you had only one file all further changes would have to stop until all changed data blocks had been written to disc. By insisting on a minimum of two log files Oracle can allow the log writer to fill the second log file as the database writer writes out the dirty blocks covered by changes desrcibed in the first log file.What about having a big size redo log file instead of two? Checkppoint being initiated when the redo log file is half filled
I mean, understand the logic, two is better, even best.. but still not getting convinced. I am just trying to think, can not Oracle work with 1 group with 1 big file..specailly when Noarch mode ? Having
Edited by: pgoel on Mar 12, 2011 7:27 PMNo, you still didn't understand and I am not sure how else we can say it. Okay, think about log groups as two buckets which are used to fill the redo content. The LGWR is filling one bucket at a time till it can't accept any more content. Once filled, rather than spilling the content out, it jumps over to the second bucket. Now, taking your statement of big sized redo, Pgoel, it doesn't matter how big sized bucket you bring in, eventually it will fill in. Its not possible that you wont be able to fill it , it just would take more longer than the normal timings. Thats all. So in any case , you need the second bucket. And I am not sure that why you are struck on the archivelog mode. I hope you do understand that its an optional mode. This means, this may or may not be there. If there, its a good thing that before doing the flush of the redo content, Oracle would be able to save the contents in the archived (think about the name, it's very meaning is to preserve, to archive) log file. If not, the redo content wuold be lost and there won't be any record of transactions leaving you to reenter the lost transactions. Its a meaningless point on which you are struck i.e. the archive or no-archivelog mode. Be it whatever, Oracle would still need minimum of the two log groups.
HTH
Aman....

How to recover from one corrupted redo log file in NOARCHIVE mode?

Oracle 10.2.1.
The redo log file was corrupted and Oracle can't work.
When I use STARTUP mount, I got no error msg.
SQL> startup mount
ORACLE instance started.
Total System Global Area 1652555776 bytes
Fixed Size 1251680 bytes
Variable Size 301991584 bytes
Database Buffers 1342177280 bytes
Redo Buffers 7135232 bytes
Database mounted.
But I have some applications which are depended on Oracle can't be started.
So, I tried STARTUP open. But I got error msg.
SQL> startup open
ORACLE instance started.
Total System Global Area 1652555776 bytes
Fixed Size 1251680 bytes
Variable Size 301991584 bytes
Database Buffers 1342177280 bytes
Redo Buffers 7135232 bytes
Database mounted.
ORA-00368: checksum error in redo log block
ORA-00353: log corruption near block 497019 change 42069302 time 11/07/2007
23:43:09
ORA-00312: online log 4 thread 1:
'G:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\REDO04.LOG'
So, how can I restore and recover my database?
If use RMAN, how to do that?
Any help will be appreciated.
Thanks.

Hi, Yingkuan,
Thanks for the helps.
Actually, I have 10 redo log files exists. All of them are here.
I tried your suggestion:
alter database clear unarchived logfile group 4;
The error msg I got is the same as before:
SQL> alter database clear unarchived logfile group 4;
alter database clear unarchived logfile group 4
ERROR at line 1:
ORA-01624: log 4 needed for crash recovery of instance nmdata (thread 1)
ORA-00312: online log 4 thread 1:
'G:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\REDO04.LOG'
Compared to losing all the data, it is OK for me lose some of them.
I have more than 1 TB data stored and 99.9% of them are raster images.
The loading of these data were the headache. If I can save them, I can bear the lost.
I want to grasp the last straw.
But I don't know how set the parameter: allowresetlogs_corruption
I got the error msg:
SQL> set allowresetlogs_corruption=true;
SP2-0735: unknown SET option beginning "_allow_res..."
I have run the command:
Recover database until cancel
Alter database open resetlogs
The error msg I got is the following:
SQL> recover database until cancel
ORA-00279: change 41902930 generated at 11/05/2007 22:01:48 needed for thread 1
ORA-00289: suggestion :
D:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\NMDATA\ARCHIVELOG\2007_11_09\O1_MF_
1_1274_%U_.ARC
ORA-00280: change 41902930 for thread 1 is in sequence #1274
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
cancel
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: 'D:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\SYSTEM01.DBF'
ORA-01112: media recovery not started
SQL>
From the log file, I got the following:
ALTER DATABASE RECOVER database until cancel
Fri Nov 09 00:12:48 2007
Media Recovery Start
parallel recovery started with 2 processes
ORA-279 signalled during: ALTER DATABASE RECOVER database until cancel ...
Fri Nov 09 00:13:20 2007
ALTER DATABASE RECOVER CANCEL
Fri Nov 09 00:13:21 2007
ORA-1547 signalled during: ALTER DATABASE RECOVER CANCEL ...
Fri Nov 09 00:13:21 2007
ALTER DATABASE RECOVER CANCEL
ORA-1112 signalled during: ALTER DATABASE RECOVER CANCEL ...
Thank you very much. and I am looking forward to your followup input.

Database in log archive mode and redo log file in mode not archive

Hello,
I have a dabatabase running in archive log mode, recently changed, I have 5 redo log groups and one of them (the current one) shows in the v$log view, that ARC: NO, I mean, no archiving. All redo logs except it shows ARC:Yes
What does it mean?
Am I going to have problems with this redo log file?
Thanks

If you do describe on v$log, you'll find that the full column name is Archived (meaning is it archived yet?).
You could try alter system switch logfile and then check v$log again a few times after.
Use the docu for finding out more about v$ views and so on
http://www.oracle.com/pls/db102/print_hit_summary?search_string=v%24log

How do look if i have Standby Redo Log files

How do look if i have Standby Redo Log files
example of creating them..

To check existence of Standby Redo Log Files:
SQL> v$standby_log
Name                                      Null?    Type
----------------------------------------- -------- ---------------------------- GROUP#                                             NUMBER
DBID                                               VARCHAR2(40)
THREAD#                                            NUMBER
SEQUENCE#                                          NUMBER
BYTES                                              NUMBER
USED                                               NUMBER
ARCHIVED                                           VARCHAR2(3)
STATUS                                             VARCHAR2(10)
FIRST_CHANGE#                                      NUMBER
FIRST_TIME                                         DATE
LAST_CHANGE#                                       NUMBER
LAST_TIME                                          DATE
SQL> select * from v$standby_log;
no rows selected
SQL>To Create a Standby Redo Log file:
SQL> alter database add standby logfile group 11 ('/u01/app/test.log') size 5m;
Database altered.
SQL> set line 10000
SQL> select * from v$standby_log;
    GROUP# DBID                                        THREAD# SEQUENCE#      BYTES       USED ARC STATUS     FIRST_CHANGE# FIRST_TIM LAST_CHANGE# LAST_TIME
        11 UNASSIGNED                                        0          0    5242880        512 YES UNASSIGNED              0                      0
SQL>and this is how you drop:
SQL> alter database drop standby logfile group 11;
Database altered.
SQL> ! rm /u01/app/test.log
SQL>Asif Momen
http://momendba.blogspot.com
Edited by: Asif Momen on Mar 16, 2010 1:32 PM
Included DROP example

Current redo log file is lost

Hi All,
I got a scenario in which my current redo log file is lost:
Do I need to:
1)Clear log file group
(or)
2)I should perform incomplete recovery.
What are the steps I should follow to recover this current redo log file?
1)*If it is inactive* I can make use of
ALTER DATABASE CLEAR LOGFILE UNARCHIVED GROUP 2;
which will drop and recreate the log file.To recover from loss of an active online log group in NOARCHIVELOG mode:
If the media failure is temporary, then correct the problem so that the database can reuse the group when required.
Restore the database from a consistent, whole database backup (datafiles and control files) as described in "Restoring Datafiles Before Performing Incomplete Recovery". For example, enter:
% cp /disk2/backup/*.dbf $ORACLE_HOME/oradata/trgt/
Mount the database:
STARTUP MOUNT
Because online redo logs are not backed up, you cannot restore them with the datafiles and control files. In order to allow the database to reset the online redo logs, you must first mimic incomplete recovery:
RECOVER DATABASE UNTIL CANCEL
CANCEL
Open the database using the RESETLOGS option:
ALTER DATABASE OPEN RESETLOGS;
Shut down the database consistently. For example, enter:
SHUTDOWN IMMEDIATE
Make a whole database backup.
To recover from loss of an active online redo log group in ARCHIVELOG mode:
If the media failure is temporary, then correct the problem so that the database can reuse the group when required. If the media failure is not temporary, then use the following procedure.
Begin incomplete media recovery, recovering up through the log before the damaged log.
Ensure that the current name of the lost redo log can be used for a newly created file. If not, then rename the members of the damaged online redo log group to a new location. For example, enter:
ALTER DATABASE RENAME FILE "?/oradata/trgt/redo01.log" TO "/tmp/redo01.log";
ALTER DATABASE RENAME FILE "?/oradata/trgt/redo01.log" TO "/tmp/redo02.log";
Open the database using the RESETLOGS option:
ALTER DATABASE OPEN RESETLOGS;
My question is when the redo log file is current. What steps we should follow?
Best regards,
Rafi.
http://rafioracledba.blogspot.com/
2)If it is active then I can make use of below steps:

Rafi (Oracle DBA) wrote:
Hi Asif,
This link I have seen by refering to previous post.I just have a slight doubt in mind.
1)Do I need to make use of statement:
Alter database clear unarchived log file group#;
(or)
Only if your group is current(or you are not able to drop it) and is not archived then you should use above query.
We should perform incomplete recovery for this.If we have to perform incomplete recovery what are the steps I should follow?
I doubt you should be performing incomplete recovery for this.
Eg:Let us say my group 1 is dropped it has only one member and it is in active state.How to recover database?Can I get the steps?
You would not be able to drop it if it is in active state, did you meant it is corrupted? If yes then you can use below query
Alter database clear [unarchived] LOGFILE GROUP #;>
Best regards,
Rafi
http://rafioracledba.blogspot.com/
Make sure to backup your database after above activity.
Regards
Anurag

How to disable write to redo log file in oracle7.3.4

in oracle 8, alter table no logged in redo log file like: alter table tablename nologging;
how to do this in oracle 7.3.4?
thanks.

user652965 wrote:
Thanks very much for your help guys. I appreciate it. unfortunately none of these commands worked for me. I kept getting error on clearing logs that redo log is needed to perform recovery so it can't be cleared. So I ended up restoring from earlier snapshot of my db volume. Database is now open.
Thanks again for your input.And now, as a follow-up, at a minimum you should make sure that all redo log groups have at least 3 members. Then, if you lose a single redo log file, all you have to do is shutdown the db and copy one of the good members (of the same group as the lost member) over the lost member.
And as an additional follow-up, if you value your data you will run in archivelog mode and take regular backups of the database and archivelogs. If you fail to do this you are saying that your data is not worth saving.

Hoping for a quick response : EXP and Archived REDO log files

I apologize in advance if this question has been asked and answered 100 times. I admit I didn't search, I don't have time. I'm leaving on vacation tomorrow, and I need to know if I'm correct about something to do with backup / restore.
we have 10g R2 running a single instance on a single server. The application vendor has "embedded" oracle with their application. The vendor's backup is a batch file using EXP - thus:
exp system/xpwdxx@db full=y file=D:\Orant\admin\db\EXP\db_full.dmp log=D:\Orant\admin\db\EXP\db_full.txt direct=y compress=y
This command is executed nightly at midnight. The files are then backed up by our nightly backup to offsite storage media.
Te database is running in autoarchive mode. The problem is, the archived redo files filled the drive they were being stored on, and it is the drive the database is on. I used OS commands to move 136G of archived redo logs onto other storage media to free the drive.
My question: Since the EXP runs at midnight, when there is likely NO activity, do I need to run in AutoArchive Mode? From what I have read, you cannot even apply archived redo log files to this type of backup strategy (IMP) Is that true? We are ok losing changes since our last EXP. I have read a lot of stuff about restoring consistent vs. inconsistent, and just need to know: If my disk fails, and I have to start with a clean install of Oracle and nothing else, can I IMP this EXP and get back up and running as of the last EXP? Or do I need the autoarchived redo log files back to July 2009 (136G of them).
Hoping for a quick response
Best Regards, and thanks in advance
Bruce Davis

Bruce Davis wrote:
Amardeep Sidhu
Thank you for your quick reply. I am reading in the other responses that since I am using EXP without consistent=y, I might not even have a backup. The application vendor said that with this dmp file they can restore us to the most recent backup. I don't really care for this strategy as it is untested. I asked them to verify that they could restore us and they said they tested the dmp file and it was OK.
Thank you for taking the time to reply.
Best Regards
BruceThe dump file is probably ok in the sense it is not corrupted and can be used in an imp operation. That doesn't mean the data in it is transactionally consistent. And to use it at all, you have to have a database up and running. If the database is physically corrupted, you'll have to rebuild a new database from scratch before you can even think about using your dmp file.
Vendors never understand databases. I once had a vendor tell me that Oracle's performance would be intolerable if there were more than 5 concurrent connections. Well, maybe in HIS product ..... Discussions terminated quickly after he made that statement.

Restore in noarchivelog mode ( redo log files have been dropped )

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