Re: Why Backup Temp and Rollback segs?

From: Jeremiah Wilton <jeremiah_at_wolfenet.com>
Date: Mon, 19 Oct 1998 12:38:29 -0700
Message-ID: <Pine.OSF.3.95.981019122834.16447D-100000@gonzo.wolfenet.com>

On Mon, 19 Oct 1998, Chris Chesney wrote:
>
> What about online redo logs? Not the stuff that's been archived, but the actual
> redo log members? I've read articles warning against backing up the online redo
> logs, but have ran into complications when restoring the entire database to a new
> server. We are using this process to refresh QA instances from production. Do we
> need to back up the online redo logs with our cold backup script?

The online redologs are useful if you are taking a cold backup, so that you won't have to re-initialize new ones upon open of the restored database. They are required if you are taking a cold backup of a crashed database, such as one that has been shutdown with the ABORT argument.

In hot backups, online redologs are not backed up. When you finish copying datafiles, and switch the last tablespace out of backup mode, you issue an "alter system archive log current;" which will archive the currently unarchived online redologs, giving you enough redo to completely recover using that hot backup.

--
Jeremiah Wilton http://www.wolfenet.com/~jeremiah Received on Mon Oct 19 1998 - 14:38:29 CDT