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[scrsadmin]

What if any reasons are there to shutdown the production database? I have advised my manager that i would like to backup our database offline once a week. He asked why couldn't we leave it up forever and just do online/hot backups.

I could use some advise here from all of you!
Reasons to leave it up all the time...
Reasons to bring it down on a schedule like once a month or so....

 

[Thargy]

scrs,

if you do it right, you need never bring a database down, other than for planned maintenance and upgrades. There you go, one reason to shut down is for upgrades.

Backup should be done using RMAN, which is the Oracle built-in backup system. Don't even consider using anything else. RMAN can do hot back-ups (i.e. a back up with the database running).

If you plan your storage handling well, e.g. use ASM, and OMF, you should be able to fire up a database, and leave it there for ages.

Another reason to shut down is when you practice your recovery. You should not only back up your database, but practice recovery from that back up. You might want to shutdown a database, take a cold backup (in case the recovery fails) and then attempt a recovery, just to prove that your system works ok.

Regards

T

Grinding away at things Oracular

 

[SantaMufasa]

Scrsadmin,

I have databases that have been running, without interruption, for multiple years. So, there is not necessarily an overriding business or technical reason to shutdown a database on a regular basis "just 'cuz".

Here is some background information that you will need to consider when making your decisions about backups:

The business purpose for a database often dictates its backup strategy:[ul][li]"Fiduciary" environment. A fiduciary application is one in which the application stores "trusted" information, for example, financial applications, or any other data for which a single transaction or loss of information is unacceptable. In such case, Oracle offers ARCHIVELOG MODE, which records changes in both the database and in on-line and archived redo logs.

In an ARCHIVELOG MODE environment, you have the luxury of performing hot backups...backups which can occur while the database is up and running and while users are updating information.

The quality of hot backups do not differ from the quality of cold backups. You can use files from either type of backup as the basis for recovery of the database to the most recently COMMITted transaction.

ARCHIVELOG MODE is the only environment which supports/allows full database recovery. (If you are not in ARCHIVELOG MODE, then the best you can hope for is a RESTORE of the database to when the last cold backup or export occurred.)

The major cost of ARCHIVELOG MODE is generally a higher consumption of disk space to accommodate the archiving of on-line redo log files as they fill.

[/li][li]"Non-fiduciary" environment. Often times, databases contain "sand box" information such as test data or reproduceable development data/code that someone can quickly/easily reload from recent exports and/or scripts. In such an environment, one does not need to incur the additional costs of ARCHIVELOG MODE. In that case, recent exports of the "sand box" schemas or full, cold backups of the database may be sufficient for your organization's needs.[/li][/ul]

Keep in mind that in the latter enviornment (NOARCHIVELOG MODE), [ul][li]recovery is not an option...only restore (to last backup).[/li][li]Hot backups are not an option, only cold backups and exports are available in NOARCHIVELOG MODE.[/li][/ul]

So, bottom line, if your database is in ARCHIVELOG MODE, then you do not need to shut down the database for backups -- Use hot backups to avoid unnecessarily bringing down the database.

If you are in NOARCHIVELOG MODE, then hot backups are not an option.

In either case, you can use Oracle's RMAN feature/module to handle your backups for you.

Let us know if you have questions or want additional input from us.




Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]

 

[SantaMufasa]

One can tell by the wordiness of my reply that my cross-posting with Tharg resulted from my typing at the time that Tharg was posting. Sorry.

I'll delight in the day that Tek-Tips installs a feature that advises posters of other person's replies that occur during "composition mode".

Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]

 

[KenCunningham]

I would only add that in my experience it is also a function of the underlying Operating System. Any Windows-based databases I have had tend to go down far more more often than my unix equivalents.

I want to be good, is that not enough?