RE: Just A Question. Regarding Backup strategy for Oracle Database with Terra Bytes of Data.
Date: Wed, 12 Dec 2012 13:39:55 -0500
Message-ID: <01a101cdd898$1521aed0$3f650c70$_at_rsiz.com>
+1. No, +1,000,000,000,{at least another 42 zeros} to Tim's response.
PLUS, from a business perspective, you might suggest that your executive team considers the loss rate per hour of downtime due to an unexpected being required recovery when arriving at MTTR and XTTR. And especially to remember that the loss rate per hour of downtime is RARELY linear. It is very probably a step function on duration and varies in cost by time of day as well as duration. Thinking this way helps create an appropriate budget for the creation of a recoverability strategy. Depending on the business and the application a 4 hour outage might mean 2 cents or bankruptcy (or sometimes worse: loss of market share). Notice also that cost varies not only by time and database, but by application. So where Tim refers to application user below, you need to repeat this exercise for a lot of areas. (Getting payroll out and tax reports in might only have to happen every two weeks, but if you let build to order instructions run out at a factory or pick slips at a warehouse or cannot take orders you might start losing money right away.)
And double down on "Recoverability Strategy" which is a part of your "Business Continuation Strategy" should a larger disaster be involved. (Hint: You create a backup strategy to serve a recoverability strategy, NOT the other way round. Once you have a recoverability strategy agreed to meet your service level requirements you can create a backup strategy that serves it AND lives within the bounds of degradation of operational performance that is allowed.)
mwf
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Tim Gorman
Sent: Wednesday, December 12, 2012 9:26 AM
To: oracle-l_at_freelists.org
Subject: Re: Just A Question. Regarding Backup strategy for Oracle Database
with Terra Bytes of Data.
Sheldon,
It is crucial to clearly understand and document your application users's
educated expectation for uptime and recoverability before designing a
recoverability strategy (please note the term "recoverability strategy" and
not "backup strategy"). If you don't have agreed-upon numbers for MTTR
(mean time to repair) and XTTR (maximum time to repair), then you don't have
enough information to create a suitable recoverability strategy.
Initial recommendations, just for setting expectations...
- For databases supporting OLTP applications, "hybrid" OLTP/DW/BI applications, or poorly-designed DW/BI applications, cycles of RMAN incremental backups o for such databases with low MTTR requirements, flashback database, block-change tracking, and one (or more) Data Guard standby databases and backups of the standby
- For databases supporting DW/BI applications, partitioning large tables by time, grouping table- and index-partitions into tablespaces, setting tablespaces to READ ONLY as they age, and then cycles of RMAN incremental backups; a low-priority, less-frequent cycle for the READ ONLY tablespaces, and a higher-priority, more-frequent cycle for READ WRITE tablespaces and archivelogs.
Also, if QA/test and development databases are not being refreshed regularly as clones from production backups, then there it is uncertain whether backups are recoverable, and therefore useless. Even if the application is a pure COTS and no development is necessary, a QA/test environment for upgrades, patches, and releases is necessary, and it should be cloned regularly.
As a representative for the ORA600 "DUDE" product (i.e. www.ora600.be), I hear from those who didn't understand recoverability, or who didn't test recoveries. It's as much about grief-counseling as it is about properly using a last-resort data-extraction utility.
Hope this helps...
Kind regards,
-- Tim Gorman consultant -> Evergreen Database Technologies, Inc. postal => PO Box 352151, Westminster CO 80035 website => http://www.EvDBT.com/ email => Tim_at_EvDBT.com mobile => +1-303-885-4526 fax => +1-303-484-3608 Lost Data? => http://www.ora600.be/ for info about DUDE... On 12/11/2012 11:42 PM, Sheldon Quinny wrote:Received on Wed Dec 12 2012 - 19:39:55 CET
> Hi,
> I would like to know what type of strategy is been use by other DBA's for
> Making backups of Production DB which are in Terra bytes.
>
> Please let me know your inputs.
>
> Thank you.
>
> Regards,
> Sheldon.
>
>
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