RE: Just A Question. Regarding Backup strategy for Oracle Database with Terra Bytes of Data.

  • From: "Mark W. Farnham" <mwf@xxxxxxxx>
  • To: <tim@xxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 12 Dec 2012 13:39:55 -0500

+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@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Tim Gorman
Sent: Wednesday, December 12, 2012 9:26 AM
To: oracle-l@xxxxxxxxxxxxx
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@xxxxxxxxx
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:
> 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.
>
>
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
>



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