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Re:RE: RE: Online vs offline backups

From: <dgoulet_at_vicr.com>
Date: Wed, 19 Jun 2002 08:38:38 -0800
Message-ID: <F001.00481622.20020619083838@fatcity.com>


Jeremiah,

    That makes a lot of sense to us DBA's, but try to explain that to your Uniz SA? I've tried and failed. So I just let him backup everything. Then when we need or do a restore I tell him exactly what files I want & leave out the online redo logs. One other reason for that if you ever run into this, is when the system that was the source of the backup completely fails, burns up, or is otherwise destroyed so that you can't get to any of the data thereon. Then that complete backup may be your only way to get "a" database back. Been there, done that, may that deamon NEVER darken your door.

Dick Goulet

____________________Reply Separator____________________
Author: Jeremiah Wilton <jwilton_at_speakeasy.net>
Date:       6/19/2002 8:08 AM

There is actually a reason for the idea that it is a bad idea to backup online logs in a cold backup.

Assuming the cold backup is for an archivelog mode database, then after restoring the database and starting up the instance, the database will come all the way open instantly with a simple startup command, making it impossible to apply the archived redologs and roll forward to a point in time.

Chal Ping got mixed up and confused the "don't backup online logs while the instance is running" rule with the problem we are discussing today.

So it is fine to backup online logs in a cold backup (why are you doing a cold backup again?). Just restore them to an alternate location by default so that you don't open the database accidentally and prevent yourself from rolling forward using archived redologs.

So, why is resetlogs a "messy" way to create your logs? I do it all the time. Maybe my new login should be pigpen.

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton

On Wed, 19 Jun 2002, Mercadante, Thomas F wrote:


> What? Makes no sense. Why NOT backup everything if you are taking a Cold
> Backup. Why make yourself perform an open reset logs upon a recovery?
>
> This is bad advice.
>
> Personally, I use Rman performing hot backups all the time. My database is
> *always* open to the world.
>
> -----Original Message-----
>
> >The same person that advocated a cold backup
> >did not back up the online redo logs, so what use was it anyway, since the
> >only way they would force open their DB is with a resetlogs option anyway.
> For cold backup, oracle does not recommend backup the online redo
> log. And if you restore the whole cold backup, why need the online redo log?
> I am sure people doing cold backup will do shutdown normal/immediate, not
> shutdown abort.So there is no need to backup the online redo log at all!
> Backup the online redo log also take the risk of damage the current online
> redo log when you want to do full recovery.
> So, never backup the online redo log when doing cold backup.
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: jwilton_at_speakeasy.net Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: dgoulet_at_vicr.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Received on Wed Jun 19 2002 - 11:38:38 CDT

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