Re: RMAN and archive log current

On Sep 27, 7:48 am, joel garry <joel-ga..._at_home.com> wrote:
> On Sep 26, 12:27 pm, Cristian Cudizio <cristian.cudi..._at_yahoo.it>
> wrote:
>
>
>
> > On 26 Set, 21:08, Michael42 <melliot..._at_yahoo.com> wrote:
>
> > > Hello,
>
> > > With Oracle 10g and RMAN I have a question concerning the following
> > > operation:
>
> > > alter system archive log current
>
> > > Should I perform this just before or just after my RMAN backup?
>
> > > Thanks for clarifying,
>
> > > Michael
>
> > it is better to execute it before backing up your archived logs. That
> > guarantes that
> > on backup you have the most data possible.
>
> > regards,
>
> > Cristian Cudizio
>
> >http://oracledb.wordpress.comhttp://cristiancudizio.wordpress.com
>
> I've been sort of wondering about this advice:http://www.freelists.org/archives/oracle-l/09-2007/msg00487.html
>
> In O8i I found strangeness with respect to arcs generated during the
> backup, right near the end of the backup, but I don't know if that
> applies to more modern versions (probably not).
>
> jg
> --
> @home.com is bogus.
> "I vomited after playing [Halo 3] for about 11 hours, but then I went
> back and started playing again, it's that good." - Reviewer heard on
> radio (day before release).
> "Just hours after yesterday's release of the Xbox 360 video game "Halo
> 3," some die-hard fans found that special limited-edition packaging
> had scratched their discs. " - AP story

I'd wonder about that advice too, because it's chronically **bad** advice (or at least, deficient in detail).

Since 9i, there has not been a need to archive log current AT ALL. Because RMAN does that command for you, automatically. Thus:

SQL> archive log list

Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /oracle/11g/dbs/arch
Oldest online log sequence     18
Next log sequence to archive   20
Current log sequence           20

SQL> exit

oracle_at_actinium:~$ rman target /

Recovery Manager: Release 11.1.0.6.0 - Production on Thu Sep 27 18:56:12 2007

RMAN> backup database plus archivelog;

Starting backup at 27-SEP-07
current log archived
using target database control file instead of recovery catalog [...]
Starting backup at 27-SEP-07
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archived log backup set channel ORA_DISK_1: specifying archived log(s) in backup set input archived log thread=1 sequence=21 RECID=6 STAMP=634417019 channel ORA_DISK_1: starting piece 1 at 27-SEP-07 channel ORA_DISK_1: finished piece 1 at 27-SEP-07 piece handle=/oracle/11g/dbs/0bit0rrr_1_1 tag=TAG20070927T185659 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02 Finished backup at 27-SEP-07

RMAN> exit

Recovery Manager complete.
oracle_at_actinium:~$ sqlplus / as sysdba

SQL*Plus: Release 11.1.0.6.0 - Production on Thu Sep 27 18:57:14 2007

Copyright (c) 1982, 2007, Oracle. All rights reserved.

SQL> archive log list

Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /oracle/11g/dbs/arch
Oldest online log sequence     20
Next log sequence to archive   22
Current log sequence           22

...and you'll notice that the current log sequence number has incremented by 2. The reason for that is obvious to the eagle-eyed: You'll notice that one of the very first things listed in the RMAN feedback is "Starting backup at 27-SEP-07 current log archived". The clue is in the last three words there. And you'll notice the same thing happening at the beginning of the bit of the backup process that finally turns its attention to backing up the archives.

The above example is with 11g, obviously, but the same behaviour will be observed in 9i and above. The only requirement is to use the 'plus archivelog' syntax in your backups. Received on Wed Sep 26 2007 - 18:17:40 CDT