Re: Online backup...

From: Charles Jardine <cj10_at_cam.ac.uk>
Date: 1997/08/15
Message-ID: <33F46793.7C7E_at_cam.ac.uk>#1/1


Phil Harris wrote:
>
> I am looking at implementing a backup strategy for our db (7.3...).
>
> It is running 24 * 7 and therefore I need to make online backups.
>
> I have just attended the BR7, and they say that it is fine. Just set the
> table space to backup mode, the do an operating system copy. The actual
> backup may be inconsistent, but when you apply the redo logs, it'll iron
> it all out...
>
> Does anyone have any advice for me. Is it really as easy (and as
> reliable) as the bloke made out, or is it a real nighmare???

It really is that easy.

The vital thing is to have the logs you will need stored with the backup. (Of course, the database must be in ARCHIVELOG mode.)

After you have done the last ALTER TABLESPACE ... END BACKUP do an ALTER SYSTEM ARCHIVE LOG CURRENT. Then copy the archive log files to the backup medium.

You can find which logs you will need by looking at the current log number before and after the backup. You can get the current log number by: SELECT MAX(SEQUENCE#) FROM V$LOG. The archive logs you will need are those from the log which was current before you started up to the one which was forced out by the ALTER SYSTEM ARCHIVE LOG CURRENT. (I look at the current log number after the ALTER SYSTEM and subtract one).

(NOTE: All the above applies to a single threaded server. If you have multiple log threads it is more complex). Received on Fri Aug 15 1997 - 00:00:00 CEST

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