RE: performance impact of archivelog
Date: Tue, 18 Nov 2008 09:25:57 -0600 (CST)
This is a very interesting thread. In my last shop, I was of this very opinion - Why backup a DW that is incredibly large with innumerable unrecoverable points, and where many objects are completely refreshed in relatively short periods of time?
I was outvoted by the same rationale you see here. Some points for the archivelogging side of things:
Certain recovery situations might be more transparent; Recovery from a disaster might be more straightforward.
On the other side:
Can you afford to have an DW down while it's rebuilt?
With a great deal of nonrecoverable points, wouldn't much it have to be rebuilt logically even in archivelog mode?
Are these business or technical issues?
While I think the answer SHOULD be techical (if it's a traditional DW model), I've seen businesses violate the model and use the DW for nonconventional queries (such as online order history, etc).
Interesting topic for list discussion.
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of David Ballester
Sent: Tuesday, November 18, 2008 3:58 AM To: Greg Rahn
Cc: renatomelogomes_at_gmail.com; david.h.roberts_at_logica.com; czeiler_at_ecwise.com; oracle-l_at_freelists.org Subject: Re: performance impact of archivelog
El lun, 17-11-2008 a las 14:44 -0800, Greg Rahn escribió:
> And I personally would never run a production database in noarchive
> log mode. Never.
I can understand your opinion about the archive log mode on production databases, but in very special situations - for example a datawarehouse with 20 TB of data aprox. renewing a lot of data each hour and 24X7, is very difficult to maintain a backup in the Oracle standard mode ( hot backup with rman with archive log mode on ). No window to backup all data, the nologging inserts making a lot of unrecoverable points... we are talking about tablespaces of 360GB, who can backup it at reasonable speed? - I think that in very special cases - other example that comes to my mind, a instance used as application cache or very volatile data - the database could be in noarchivelog mode but after a carefully study, of course. I'm with you, but I say 'For the 99,9% of production databases I would never run it in noarchive log mode' :)
D.Received on Tue Nov 18 2008 - 09:25:57 CST