Possibly because they are thinking in the
context of RMAN, and rman never backs
up the online redo logs.
--
Jonathan Lewis
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Keith Boulton wrote in message ...
>I started this as a new thread to avoid giving the impression that I was
>just continuing that argument.
>
>Tom Kyte very kindly put a reference to the Oracle Docs re inconsistent
>backups which I've just read, but they don't seem to make sense to me:
>
>"If you run your database in NOARCHIVELOG mode, only back it up when you
>have closed it cleanly using the IMMEDIATE or NORMAL options. Inconsistent
>whole database backups of databases running in NOARCHIVELOG mode are usable
>only if the redo logs containing the changes made prior to the backup are
>available when you
>restore it--an unlikely occurrence. "
>
>Why is this unlikely? The set of non-archived redo logs and the database
>data files are sufficient to redo any outstanding changes - that's why we
>can't reuse a redo log until the database checkpoint is complete. There is
>no need to use archived redo logs. Surely, if you were doing a cold backup,
>you would be backing up both the database data files and the redo logs?
>
>"The reason that NOARCHIVELOG inconsistent backups are not recommended is
>that the datafile headers of the backed up files contain different SCNs (a
>normal shutdown guarantees the consistency of these SCNs), and because the
>database is in NOARCHIVELOG mode, no archived redo logs are available to
>apply the lost changes. For this reason, RMAN does not allow you to back up
>a database that has been running in NOARCHIVELOG mode and shut down
>abnormally because the backup is not usable for recovery. "
>
>There is *never* a need to use archived redo logs to perform instance
>recovery after a shutdown abort, so why this statement?
>
>
>
>
>
Received on Sat Aug 18 2001 - 10:14:45 CDT
