Re: archive log question

"utkanbir" <hopehope_123_at_yahoo.com> wrote in message news:f6c90ebe.0405310226.55e66e3a_at_posting.google.com...
> Hi Everybody,
>
> I have tb.level datawarehouse on 9.2.0.2 , itanium . linux , emc.
> Every night , batch etl processes run and add daily data to the
> datawarehouse. And everyday , we archive data by using rman . My
> question is about archive logs . Since this is a datawarehouse , there
> is no dml apart from the batch etl jobs that run night. So , this
> means , if my system needs to be restored by using backups , i can
> return to the last point of change which is one night before.
> In this case , do i need to backup archive logs?

If the only DML is the batch load, and if you have no objection to restoring the entire terabyte-sized database to the way it was the night before in the event of a media failure, then you don't need to be in archivelog mode at all. Which is precisely what you are hinting at with directing their output to /dev/null... however, the more appropriate way of doing it would be to shut the database down, get it into the MOUNT state (startup mount) and then issue the command: alter database noarchivelog; No more archives from that point on.

You should probably also make sure that ARCH is not switched on (set log_archive_start to false, or remove it completely), otherwise you'll have a background process running but not doing any work.

Without archives, however, the failure of ONE datafile will mean you have to restore the ENTIRE database from the previous backup. If you are happy doing that, then go ahead. You will also *have* to perform closed database backups of the entire database each night from this point on. Are you sure that you can back up terabytes of data in one night? And that no-one will mind the database being out of commission for the duration?

If you ever want to be able to restore single data files; or if you need to perform hot backups; or if you want to backup parts of your database each night, rather than all of it in one sitting, then you *must* be in archivelog mode, you must take proper archives, and you must back them up carefully.

I would do a bit more research at http://tahiti.oracle.com on the precise implications of being in archivelog before making any rash decisions you later come to regret.

Regards
HJR
>Is there any facility
> to point the archive logs to null like some other databases? (Or does
> dbserver use archive logs for other purpose and i must backup them
> regularly.)
>
> Kind Regards,
> tolga
Received on Mon May 31 2004 - 06:07:33 CDT