Re: Backup trends (2): HOT or COLD

Mark Bole <makbo_at_pacbell.net> napisał:

> "Binary Compression of Backup Sets
> RMAN can now write backup sets in a format that uses binary compression
> to reduce backup set size. Using compressed backup sets can save storage
> space, as well as network bandwidth when backing up across a network."

> I inherited a well-written Unix hot backup shell script that has served
> excellently through upgrades from 8.1.5 to 8.1.6 to 9.2.0, Solaris and
> Linux, almost no maintenance required. And it compressed the files! If
> not, I would have used RMAN instead.

Compression dilemma: save CPU (time) or memory :-)

> Third, it is interesting to note that Oracle has published a "RMAN Myths
> Dispelled" document on Metalink (Note:134214.1). I don't think they
> ever had to publish a "Hot backup myths dispelled" document. ;-)

> Here is an excerpt:
> Myth #1. RMAN only backs up those datablocks which contain data.
> Myth #2: Incremental backups will take significantly less time to backup
> than full backups.
> Myth #3: I can specify incremental backups during a restore operation.

Interesting.
Also new in 10g:
- incremental backups level 0 and 1 only - block change tracking in change tracking file It seems that incremental backups were too slow in backup and and not always used in recovery.

Greetings,
Lucyna Witkowska
PS. Joel, thank you for links Received on Thu May 06 2004 - 02:16:03 CDT