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Re: backup online redo log file during a hot backup

From: hpuxrac <>
Date: Fri, 22 Jun 2007 11:34:29 -0700
Message-ID: <>

On Jun 22, 2:04 pm, Massa Batheli <> wrote:
> On Jun 22, 1:50 pm, "" <> wrote:
> > On Jun 22, 12:00 pm, Massa Batheli <> wrote:
> > > This might seem out of place to those who have religiously not been
> > > backing up online redo log files but unfortunately some of us have
> > > been doing that.
> > > Question out of ignorance
> > > If you do not back them up would they be recreated from the archived
> > > redo log files when the files are restored and the database started /
> > > recovered?...
> > > Thanks for your response as usual
> > > Massa
> > The active redo log is not, I repeat not, archived unless you
> > explicitly do so with 'alter system archive log current;' at which
> > time it's no longer active, therefore if you lose this you may have
> > lost vital information necessary for instance recovery; you WILL have
> > lost the ability of Oracle to function. Active redo logs cannot be
> > 'recreated' from any archived copy of the redo logs. You really need
> > to read this:
> >
> > before you go any further.
> > David Fitzjarrell
> David
> Thanks for your very fast reply
> But that was not the point of the question.The point was do you have
> to make a copy of the online redo log files as well
> as the datafiles during a backup or the redo log files(not archived
> redo log files are left out) ?If they are omitted would the database
> come up OK
> Massa

First you can probably find if you search a whole bunch of similar discussions on this topic in cdos. You can use the google groups interface to search thru this information ...

If you use rman you cannot thru normal means get a copy of the online redo logs.

You don't restore them either thru rman.

You have to take some special steps if you have "lost or corrupted" the online redo logs like using the resetlogs option during an alter database open.

If you aren't using rman ( and you should be for 10 and up ) then doing a cold backup yes lots of the time people do get copies of them. Is that right or wrong? Opinions can vary here. For a hot backup, often yes people also do get copies of them. Should you be getting them if you are doing a hot backup and not using rman. Well lots of people have different feelings ... theoretically they are not needed.

Lots of variations ie are you using raw partitions, etc.

Tom Kyte has lots of info on his feelings about this area in both his books and over at Received on Fri Jun 22 2007 - 13:34:29 CDT

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