Re: What are the common mistakes DBA do retarding backup & Recovery?

Hi Syed,

As a recent convert to RMAN, here's my $.02:

Incrementals (and differentials, too, I assume?) -- I haven't needed to use them yet. It seems like it's most attractive to VLDBs with the majority of the blocks are static (DM/DW?) , where the added complexity is offset by the backup size and/or time. I like having that option, though.

Compression on split mirror copies can be easily done on Unix using your favorite util (compress, gzip, bzip2), where appropriate.

Encryption in RMAN is only available with a purchased option. Encryption on Unix using scripting is freely available.

"Easy" is very subjective here. Even though RMAN is provided by Oracle, whereas something like a split mirror copy will always be custom, the backup and restore procedures using RMAN will still vary from site to site. Some may use EM, some may roll their own scripts wrapped or not by shell scripts, on the server vs. centralized, etc. I think that's a wash.

One major advantage split-mirror scripts can have over RMAN is that the method is tried-and-true and IMHO are much more resilient to Oracle version change. I had been using the same basic disk-to-disk backup script from v7.4 to v10.2. The last place to use "latest-n-greatest" is in backup and recovery. Anyone try RMAN in 8.0.3??? Ewww. But I have no real RMAN complaints in 10.1.0.5.0 so far. I won't blame RMAN for the EM interface to it...

Rich

• From: "Syed Jaffar Hussain" <sjaffarhussain_at_xxxxxxxxx>
• To: "John Kanagaraj" <john.kanagaraj_at_xxxxxxxxx>
• Date: Fri, 6 Jul 2007 13:15:22 +0300

I haven't used the split mirror technology. But, I love to use RMAN and I have no hesitation recommending people to use RMAN because of the following advantages with RMAN:

Incremental Backups (Change Tracking)
Compressed backups
Encrypted backups
Easy maintenance

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