Re: Question on RMAN restore from tape

From: Mladen Gogala <>
Date: Wed, 18 Dec 2019 18:55:13 -0500
Message-ID: <>

And there lies the problem. I remember the year 2011 and NetBackup 7. Symantec support told me to turn off deduplication because it was causing problems.  How long will Oracle need to get it right? Is Oracle deduplication compatible with compression? That was, as far as I can remember, the problem with NB7. The next question is the  deduplication algorithm. DD Boost and Data Domain use two pass algorithm. Commvault uses a single-pass algorithm. Single pass algorithm reduces the space consumption anywhere between 85% and 90%. Two pass algorithm can do between 95% and 98%. However, the price for the superior space savings if inferior performance. Vastly inferior. At a client site in the state of WA, I was able to do  SAP Hana restore with Commvault twice as fast as DD Boost. DD Boost is an add on to Data Domain, with the client side signature generation. The client was a large store chain in Issaquah, WA, headquartered in a campus which also has Microsoft support building.

Now, that was a competition between two mature products, which have both done deduplication for more than a decade. Oracle has deduplication for less than a year. I would suggest the same thing done by the client above: get all the candidate vendors and have them duke it out among themselves. How fast can rman backup & restore (people sometimes forget to test restore which can be important)  with Oracle cloud module and how fast can it do it using Commvault?  I cannot give you any precise information. I have never done such test. During my tenure at Commvault, I was fighting NetBackup, TSM and Data Domain, not Oracle. That's not a reason for not organizing little hunger games between the competing vendors, this time without Jennifer Lawrence.

On 12/18/19 4:24 PM, Leng wrote:
> But of course there’s deduplications at the mml end that will filter out already backed up data.

Mladen Gogala
Database Consultant
Tel: (347) 321-1217

Received on Thu Dec 19 2019 - 00:55:13 CET

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