Re: RMAN or Hot Backup

From: jgar the jorrible <joel-garry_at_home.com>
Date: Mon, 30 Mar 2009 09:29:27 -0700 (PDT)
Message-ID: <879adcc1-6bdc-493e-b003-301bc58ad40a_at_x31g2000prc.googlegroups.com>



On Mar 27, 5:15 pm, "Bob Jones" <em..._at_me.not> wrote:
> > So yes, it is DBA basics.  I really have not done too many Hot
> > Backups, which is why I was asking what others opinions and experience
> > with both are.
>
> I have no idea why you guys keep referring to non-RMAN backup as "hot
> backup". That is just wrong terminology.

We are referring to the copying of Oracle files while the db is running. This results in an inconsistent set of data files, which can be made consistent on recovery by the application of redo. However, if the data files are not placed into backup mode before copying, there may not be enough information in redo to make them consistent.

RMAN inconsistent backups are also hot backups, but RMAN is smarter than operating system utilities and can copy the blocks in the data files in a way that avoids the problems of redo, as well as avoiding suspending the system.

In this thread, and fairly commonly, the distinction is made by calling the OS inconsistent copies hot backups and the RMAN inconsistent copies RMAN backups. There are other similar slackoffs like people calling physical backups "backups" and saying logical backups are not backups at all, and if you understand the underlying assumption that people need to recover transactions, it makes more sense, though this can be more confusing in non-transactional restoration environments.

What terminology do you use?

jg

--
_at_home.com is bogus.
Yes, Miss California used to run around my neighborhood.
http://www.sdbackyard.com/?page_id=1000&site_page_id=5&post_id=52007
Received on Mon Mar 30 2009 - 11:29:27 CDT

Original text of this message