Date: Thu, 28 Aug 2008 09:53:50 -0700 (PDT)
On Aug 28, 9:07 am, artme..._at_yahoo.com wrote:
> On Aug 28, 5:36 am, Cristian Cudizio <cristian.cudi..._at_yahoo.it>
> > On 27 Ago, 20:19, artme..._at_yahoo.com wrote:
> > > Hi,
> > > We're setting up RMAN and configuring our environment. We are on
> > > Oracle 10gR2. I'm having trouble understand these commands:
> > > CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET
> > > PARALLELISM 20;
> > > CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '/disk1/ora_df%t_s%s_s%p';
> > > They both specify disk. But, can they be combined into one command?
> > > The documentation is really not specific on this. They show different
> > > variants of the above, but I did not find anything on a combination of
> > > the commands. If we can do it in one command, it makes more
> > > sense......
> > > Thank you.
> > If you seehttp://download.oracle.com/docs/cd/B19306_01/backup.102/b14194/rcmsyn...
> > you can configure different formats for different channels (for
> > different backup pieces and one backupset)
> > while "parallelism" and "compressed backupset" are "global" settings
> > for a backup set
> > you can configure different settings for different channells that
> > write different backup sets.
> > Hope this helps.
> > Regards,
> > Cristian Cudizio
> You know, I read someplace that it is good to put each datafile in its
> own backup piece. Their reason was that when performing partial
> restore the files are smaller to read and the restore will be quicker.
> Is there any truth to this?
I almost posted this, but held my tongue because of all the sitespecific permutations possible. It's true for me, I limit the files to 4, and the size of my datafiles to 2G. It can be particularly true if you are searching for certain archived logs among many, but that's a whole 'nother kettle of worms. I originally limited the files to 7, but in a version long ago that gave PGA issues, so went to 4. (I'm reconsidering this as I convert to 10g, and haven't really settled on an exact configuration yet.)
Also see the OracleŽ Database Backup and Recovery Advanced User's Guide section about tuning RMAN performance, large_pool_size made a big difference for me, at least in earlier versions on my configuration, and I've kept it for 10g.
Hardware and OS does make a difference in these things.
-- @home.com is bogus. "You let the Mormon beat you on a booze question!" - heard on radio trivia game as Ken Jennings tours promoting his new book.Received on Thu Aug 28 2008 - 11:53:50 CDT