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
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
www.ubs.com
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