Tom,
I did a quick test a couple of years ago (I think it was on 7.3.4) and found
that when starting up after a clean shutdown Oracle doesn't actually read
the redo logs, it just needs the files in the right location. Three step
test.
1. Clean shutdown (immediate) of small test db. Removed redo
Technically, after a consistent shutdown, the redo logs are not needed. All
transactions have been completed thus no redo is necessary.
However, I consider a full backup to include redo logs and control files.
The issue is not whether the database needs them for recovery, but whether
the dba
Tom, that statement will open a can of worms(like a religion following)
about if/when to backup redo logs. :)
joe
Mercadante, Thomas F wrote:
I agree with you Joe.
I would *never* use an undocumented parameter unless Oracle told me to (or
unless I was testing something that I could
Well, it didn't sound like he was using Rman (which does not backup redo
logs). So I assumed that he was/should be using a cold-backup strategy -
which, if it were me, would backup the redo logs.
Tom Mercadante
Oracle Certified Professional
-Original Message-
Sent: Friday, September
I'm not an expert so pardon me if i'm wrong.
Why to copy the log files in case of a cold backup if the instance was
shutdown cleanly(NOT ABORT)??
The d/b will be consistent so we don't need the redo-log files, isn't it?
Isn't it that the DB update all the Datafiles headers with the checkpoint
Naveen,
Why NOT take the redo log files in a cold backup?
If you restore these cold backup files and intend to use them, you would
then have to open the database with the RESET LOGS option to re-create the
redo logs.
This would then invalidate all of your archive log files.
And Joe - thanks!
My long standing position on this is that you take backups so that Just in
case something fails, you have the ability to recover. If something has
failed, I want backups of EVERYTHING. I know I dont' need the redo logs,
but I would feel awful silly if I needed them at some point but didn't back
I agree, there is never a problem because you backed up redo log files.
There could
be a problem with inadvertently restoring them, covering up needed information
in the
current online redo logs.
John
[EMAIL PROTECTED] wrote:
My long standing position on this is that you take backups so
John, seeing as your e-mail name is Ora NT DBA, you probably should have
qualified your reply with as long as the DB is down. Backing up live
Oracle files on Windows (even NTFS) is a recipe for disaster due to locking
problems (with the OS/filesystem or the backup software, I'm not sure). We
Thomas,
If you rely on the premise that cold backups can only be taken after a
non-abort shutdown, then there is no reason to backup on-line redo
logs. (If you rely on backing up redo because you do cold backups after
shutdown abort, well, then we can have an argument about best
practices.) In
Hey Gilberto, I was just yanking your chain with the CV line.
Well done for getting the thing back
Regards
Lee
-Original Message-
Sent: 19 September 2002 19:08
To: Multiple recipients of list ORACLE-L
Hi People
I don't think that i need to update my CV, since I don't administer the
update your CV
-Original Message-
Sent: 18 September 2002 21:30
To: Multiple recipients of list ORACLE-L
Hi people...
What to do if I have LOST ALL REDO LOGS and i don´t have any backup?
Thanks in advance!
:
Gilberto
And preferably, forget about this little incident when doing so...;-)
On Thu, 2002-09-19 at 05:43, Robertson Lee - lerobe wrote:
update your CV
-Original Message-
Sent: 18 September 2002 21:30
To: Multiple recipients of list ORACLE-L
Hi people...
What to do if I have LOST
If you lost the redo logs *after* you shutdown the database, you can do the
following to re-create them:
1. As DBA: startup mount;
2. alter database backup controlfile to trace;
3. select * from v$controlfile;
4. shutdown
5. Delete the controlfiles identified by (3) as these need to be
As I stated earlier, right out of the user managed recover docs(loss of
all online redo logs):
you'll need to do the restore from backup, using what archivelogs
available roll forward to point of last archived log and open resetlogs
--- the abbreviated version.
joe
Recovering After
KG, doesn't anyone think not having a backup is a bad thing.
You can go down that route if you wish but as I remember undocumented
parameters are best used with the assistance of OWS and not just used at
will.
joe
K Gopalakrishnan wrote:
Arun:
You are right. The original poster *clearly*
Joe:
I understand what you say.. But the situation is
very bad. He does **NOT** have ANY backups.
KG
-Original Message-
Sent: Thursday, September 19, 2002 4:43 AM
To: Multiple recipients of list ORACLE-L
As I stated earlier, right out of the user managed recover docs(loss of
all
I agree with you Joe.
I would *never* use an undocumented parameter unless Oracle told me to (or
unless I was testing something that I could recreate).
Using these params on the advice of someone from this list is very
dangerous.
The larger question is, why are the redo logs not being backed
that only OWS can diagnose and overcome...
...need my coffee, NOW!
- Original Message -
From: Tim Gorman
To: [EMAIL PROTECTED]
Sent: Thursday, September 19, 2002 7:03 AM
Subject: Re: Lost ofall redo logs
One correction...
The undocumented "_corrupted_rollback_segments"
par
There is the other expensive avenue of calling in Oracle and
the DUL team. It depends on the criticality of the data.
A few years ago a former dba here had the experience and
it is said to have cost a mere $20K. Maybe the data is
worth more than that.
On Wed, Sep 18, 2002 at 10:08:19PM
to get the database up if it is crashed (read:
shutdown ABORT).
Could you please elaborate please?
Thanks,
Viral Desai.
From: Mercadante, Thomas F [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Subject: RE: Lost ofall redo logs
Date: Thu
w database. Using these parameters will put the database on life-support
for a short time only, hopefully long enough to extract its data. It would
be foolish to entrust new data to it ever again...
Hope this helps...
-Tim
- Original Message -
From: "K Gopalakrishnan" [EMAIL PRO
Hi People
I don't think that i need to update my CV, since I don't administer the
database in subject and that am trying to solve the an unhappy customer's
problem.
I had already researched and tried almost everything that you suggested me
and what really solved went use to suggestion of the
Hi people...
What to do if I have LOST ALL REDO LOGS and i don´t have any backup?
Thanks in advance!
:
Gilberto Gampert Universidade de Passo Fundo
Administrador de Banco de Dados Passo Fundo - RS -
What about mirrored redo group members?
Igor Neyman, OCP DBA
[EMAIL PROTECTED]
- Original Message -
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Sent: Wednesday, September 18, 2002 4:30 PM
Hi people...
What to do if I have LOST ALL REDO LOGS and i don´t have any
Gilberto - Is your database still up, or is it down?
Dennis Williams
DBA
Lifetouch, Inc.
[EMAIL PROTECTED] mailto:[EMAIL PROTECTED]
-Original Message-
Sent: Wednesday, September 18, 2002 3:30 PM
To: Multiple recipients of list ORACLE-L
Hi people...
What to do if I have LOST ALL
The most important - do not panic.
Than, read note 94119.1 on MetaLink.
Here is a part of it:
Recovery with missing online redo logs
Missing online redo logs means that somehow you have lost your redo logs before they
had a chance to archived. This means that crash recovery cannot be
There is a way to reconstruct this files? or startup and reconstruct ?
The database is in noarchivelog...
- Original Message -
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Sent: Wednesday, September 18, 2002 5:30 PM
Hi people...
What to do if I have LOST ALL REDO LOGS
Gilberto,
Can we assume that the database crashed in the middle of the day or did this
happen when things were quite? I believe you may be in an unrecoverable
situation where you will have to go back to the last cold backup, but you say
that you have no backup which does not give me a good
The only way u can open your database is to add a parameter file
as
_allow_resetlogs_corruption=TRUE
_corrupted_rollback_segments= TRUE
_offline_rollback_segments=(the rollback segment names)
activate the database and then immediately take an export of the whole
database.
Create a new
Nop, all redo logs gone away...
- Original Message -
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Sent: Wednesday, September 18, 2002 5:43 PM
What about mirrored redo group members?
Igor Neyman, OCP DBA
[EMAIL PROTECTED]
- Original Message -
To: Multiple
Arun, since WHEN has been using undocumented parameters the normal way
of doing things, I think you need to go back and lookup backup/recovery
concepts.
Feel free to read both user managed and RMAN backup recovery docs/scenarios.
You are giving bad advice to people on the list who might be
Well one I do want to make clear I have never tried to give bad advice to
people.
Since the user in his mail had said that he does not have a backup and does
not have any online redo logs can you please let me know how else can he
open the database, when he said he does not have a back it assumes
Arun:
You are right. The original poster *clearly* said
LOST ALL REDO LOGS
NO BACKUP.
In the above situation, you have to open the
databases using the some special tricks and
I don't think you need to go back and refer
BAckup and Recovery Manuals (You can not
find anything for this situation,
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