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Vivek,
The origianl poster inquired on Physical Standby
(in 8i and 9i) as opposed to logical standby (only in 9i).
In physical standby, you don't have a choice of
running the standby in noarchivelog mode. The control file is created from the
primary as "standby controlfile" which is then implanted at the standby site.
Therefore the LOGMODE is V$DATABASE is always ARCHIVELOG and the
CONTROLFILE_TYPE is always "STANDBY".
I guess you are confused on the potential issue -
when the logmode is archivelog, whether the standby generates archived log
files. No, the standby does not generate archived logs since it does not excute
transactions; it just applies the logs shipped from the primary. When you
activate the standby to make it the primary, however, the archived logs are
generated.
Hope this clears any confusion. Do let us know if
you have more questions on this.
Arup Nanda
www.proligence.com
----- Original Message -----
Sent: Friday, September 05, 2003 3:09
AM
Subject: RE: Oracle Standby Database
Backups.
Arup,Indy,
List
Some
Clarifications please
If the Primary
Database is in ARCHIVELOG Mode (Physical Standby) & archived files there
from are being shipped & applied to the Standby Database, What is the need
to run the Standby Database in ARCHIVELOG Mode?
Are you
implying 9i Dataguard with a Standby which works on a mechanism Other than
Log-shipping?
Please give
detail
Thanks
-----Original
Message-----
From: Arup Nanda
[mailto:[EMAIL PROTECTED]
Sent: Thursday, September
04, 2003 12:35
AM
To: Multiple recipients of list
ORACLE-L
Subject: Re: Oracle
Standby Database Backups.
You
should perform backups from the Standby database, regular RMAN backups, no
need to shutdown the database. Make sure you backup the archived log files
from there too. Contrary to what the docs might _imply_, I use the word
"imply" rather than "state", since the docs have been kind of ambiguous, the
archivedlog backups from the standby are perfectly alright to be used for
recoveries..
You could
use the RMAN backup on the primary, but why? You would rather want to offload
the CPU cycles for RMAN to the standby database. In case of a failure in the
primary, your first option is to get the files from standby and recover them.
If standby is down too (as in case of a complete disaster), you would
reinstate the standby backup files to primary and you will be
ok.
We are
using it to backup out 7 TB OLTP database.
-----
Original Message -----
Sent: Wednesday, September
03, 2003 2:29
PM
Subject: Oracle Standby
Database Backups.
We are in the
beginning stages of designing a database with Oracle Standby
capability. The initial size of the database will be 600-800
Gig. The proposed database will be run on a IBM P690 with a mirrored
fail-over machine. Two separate machines with separate
disk. We are considering using Oracle Standby to have the
database available as much as possible.
Do I
need to perform regular backups of the Standby database? Sounds like a
silly question, but how do I do this? Using Rman? Or do I shut
it down and perform a cold backup? I will definitely use Rman on the
primary database. Just curious what you all would
suggest.
Tom
Mercadante
Oracle Certified
Professional
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