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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Rman and database shutdowns UPDATE
Ron - Thought of a simple way to explain the situation to your VMS
administrators. I've simplified a few things, but it should suffice. If I've
missed anything critical, someone will correct me ;-)
Each Oracle datafile has a transaction number recorded. The Oracle control file has a transaction number for each datafile. Before Oracle will open the database, the transaction number on the control file must match the transaction on each data file. When you shut Oracle down normal, all these numbers match, so a cold backup after a normal shutdown is valid. This is also why a cold backup after a shutdown abort or database crash can't be guaranteed.
Now, if you back the database files up while Oracle is open, the backup will take some time, and if transactions occur in Oracle, the transaction numbers will change during the backup, so the control file may not match some file transaction numbers.
Someone mentioned that you should test it. Be careful. If the database is quiet, it is possible to get a valid backup while the database is open. You wouldn't want to bet on this as a backup method, but in a test situation it could lead you to the wrong conclusion.
Okay I'll shut up and let you get back to your nap ;-)
Dennis Williams
DBA, 40%OCP
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Wednesday, February 12, 2003 10:24 AM
To: Multiple recipients of list ORACLE-L
Just got out of a meeting with the systems group. The Incremental backup
was not working because the command was written wrong. There has been a
decision to do cold backups each night.
The system people swear that the OpenVms can successfully backup an
open file (datafile) and have it recovered properly. They can backup it
up with an Ignore flag that backups up open files?
I will go with a cold backup methodology.
Ron
>>> RROGERS_at_galottery.org 02/12/03 10:18AM >>>
List,
OS OpenVms 7.3-1
Oracle 8.1.7 rel 3
Archivelog mode.
We are trying to work through backup issues here and I have a
question.
The system nightly backup procedures backup up the disks used by
Oracle
(software and data). A full backup works but an incremental does not
backup any files. Inorder to get the changed files to be backed up as
an
incremental the sysadmin shutdown the database to flag the files as
changed.
Questions:
How will the shutdown effect the RMAN backup if it does not know that
it was shutdown for a cold backup?
Are there any possible problems doing a restore from the cold backup
and then using the RMAN backup/restore?
I am still trying to figure out the OpenVms OS. Perserverience
required...!
Ron
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Ron Rogers
INET: RROGERS_at_galottery.org
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Ron Rogers
INET: RROGERS_at_galottery.org
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed Feb 12 2003 - 14:09:21 CST
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