RE: Nologging and partition exchange
- From: "Mark W. Farnham" <mwf@xxxxxxxx>
- To: <tim@xxxxxxxxx>, <Paul.Baumgartel@xxxxxxx>
- Date: Fri, 4 Jun 2010 11:15:17 -0400
And if. (meaning I agree completely with what is written so far.)
If you consider the partitioned object a live production object and the
preparatory table loaded nologging to be a "staging" object, then preserving
the recoverability of the staging object after loading but before the
exchange is a practice to consider. When the source data for the "staging"
table remains available at least through the preservation of the
recoverability of the staging object, these leaves you with no point in time
lacking a reasonable reprocessing workflow to follow when something goes
bump. And at no time do you give access to users to an object that is not
recoverable. While this does inject a lag between loading the staging object
and making the contained data part of the production image, it does maintain
the nologging advantage of minimizing the redo stream. Overall backing up
the relevant incremental routinely produces less concurrency conflict
amongst your hardware resources than the affect of injecting the extra redo.
This may or may not fit with your real world requirements, but it is a
practice worth consideration.
mwf
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Tim Gorman
Sent: Friday, June 04, 2010 9:54 AM
To: Paul.Baumgartel@xxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: Nologging and partition exchange
Paul,
After any NOLOGGING operation, please perform an RMAN incremental level=1
backup as soon as possible. Of course, level=0 or full is OK too, but the
minimum is a level=1. The time period between the completion of the load
and completion of the backup is a window of risk of possible data loss in
the event of media failure or corruption, and that window of risk is the
tradeoff (i.e. speed vs recoverability) that must be consciously accepted
using for the NOLOGGING operation.
Hope this helps...
Tim Gorman
consultant -> Evergreen Database Technologies, Inc.
postal => P.O. Box 630791, Highlands Ranch CO 80163-0791
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...
Paul.Baumgartel@xxxxxxx wrote:
When a table is loaded with NOLOGGING and /*+ APPEND */ hint, then exchanged
with a table partition, that partition remains unrecoverable, correct?
If you use this approach, how do you make the partition recoverable?
Paul Baumgartel
UBS AG
IB Accounting Solutions
400 Atlantic Street
Stamford, CT 06904
203.719.4368
paul.baumgartel@xxxxxxx
<file:///\\www.ubs.com> www.ubs.com
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