Re: Backup Question

There is one situation where you should backup the redo log files:

If you do a recovery to a point-in-time within the scope of the on-line redo log file, backup the log file just before you do the open database reset logs. This is to protect you when your user mis-informed you as to target point-in-time and you need to repeat the recovery!

Praim Sankar wrote:

> I am not sure that I understand fully why you would say oracle wants the
> log there.
>
> In the book "Oracle 8 and Windows NT Black Book", pg. 762 2nd para:
>
> "It is critical that you never restore an online redo log. In fact, Oracle
> advises against even backing up the online redo logs when the database is
> down, so that you can't accidentally restore them later. This
> receommendation is regardless of wheter you the database is operating in
> ARCHIVELOG or NOARCHIVELOG mode."
>
> I believe ( I don't have the textbook with me) that Rama Velpuri in
> "Oracle Backup and Recovery" also says the same.
>
> In my situation, I don't backup the online redo logs because of what I
> read.
>
> I am running in archivelog mode but i don't do hot backups. the database
> instance is stopped at night and a full backup of all files except the
> redo logs are copied. i tested the backup strategy and it worked fine so I
> think I am ok. Any reason why i may be conecerned?
>
> On Fri, 12 Feb 1999, Neil May wrote:
>
> > Hi,
> >
> > I think he is saying the database is running in NOARCHIVELOG mode.
> >
> > The assumption of a hot backup for a database in ARCHIVELOG mode is that
> > archivelogs are applied to it to rollforward the data past the point of
> > the online logs (as taken at backup time). Therefore the online logs are
> > useless to a recovery of a database backed up online. With a cold
> > backup, oracle wants the logs to be there so it can easily check if
> > everything is in sync.
> >
> > Andrew May,
> > Quest Software.
> >
> > John P. Higgins wrote:
> > >
> > > Forgive an ignorant question, but what does it mean when 'media recovery
> > > is disabled for the database '?
> > >
> > > Dave B wrote:
> > >
> > > > I am reading an Oracle book which says:
> > > >
> > > > "[Offline database] backups of transaction log files are useful only if
> > > > media recovery is disabled for the database ... if media recovery is
> > > > disabled, offline database backups must always include backups of the
> > > > database's transaction log."
> > > >
> > > > OK, I think I understand why transaction log files are not required for
> > > > media recovery backups ('cause the transactions in the log files were
> > > > already applied to the data files prior to shutdown, right??) BUT isn't
> > > > this always the case - even if media recovery is turned off??
> >
> >
Received on Tue Feb 23 1999 - 12:57:59 CST