Q
Problem solve Get help with specific problems with your technologies, process and projects.

Physical backups in Oracle 8i

Hi. How do I take physical backups in Oracle 8i? Thanks, Raj.


Raj,
There are two methods that you want to investigate for physical backups of any Oracle database version. The first is the "cold" backup, and the second is the "hot" backup.

The cold backup is so named due to the fact that the database is down when you back it up, i.e. cold. Basically, you peform the following steps:

  1. Bring down the database
  2. Backup the database files with OS copy commands
  3. Backup the control files, parameter files, password file with OS commands
  4. If running in Archive mode, backup the archived redo logs with OS commands
  5. Backup any other files you feel are necessary
  6. Start the database

The hot backup is so named due to the fact that the database is up and running when you back it up, i.e. hot. Your database must be running in Archive mode before you can perform a hot backup. Basically, you peform the following steps:

  1. Put a tablespace in backup mode
  2. Backup the database files for that tablespace with OS copy commands
  3. Put the tablespace in non-backup mode
  4. Repeat 1-3 for every tablespace in your database
  5. Copy the control file with the BACKUP CONTROL FILE TO TRACE command
  6. Backup the archived redo logs with OS commands
  7. Backup any other files you feel are necessary

Cold backups are easier to perform, but your database must be down to get a consistent backup. Hot backups are more complex, but your database can be up and running.

Oracle is trying to get DBAs to start using their RMAN (Recovery Manager) product. But the industry is not embracing it as well as Oracle Corp. had hoped. Part of this lies in two areas. One, RMAN is much more complex to set up and work with. Two, DBAs are comfortable with the tried-and-true hot/cold backup methods. Put it simply, they work and they work well. RMAN has had a history of bugs, and why would I trust my backup viability to RMAN? Most of those bugs have been worked out by now, but DBAs are generally staying with hot/cold backups. So why switch to RMAN? It has a host of functionality that you cannot get with hot/cold backups. For instance, RMAN lets you perform incremental backups at the block level on a datafile. This is not possible with hot/cold backups.

I have only two more pieces of advice for you: One, when implementing a sound backup/recovery strategy, test, test, test, and test until you are blue in the face. While software can be reinstalled and systems can be reconfigured from scratch, you cannot redo data in the database without a solid backup/recovery strategy. It is your savior in times of trouble. And two, read the Oracle documentation, specifically the Oracle Backup & Recovery guide, for much more information that I have given you here.

For More Information


Dig Deeper on Oracle database design and architecture

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

SearchDataManagement

SearchBusinessAnalytics

SearchSAP

SearchSQLServer

TheServerSide.com

SearchDataCenter

SearchContentManagement

SearchHRSoftware

Close