Re: RMAN and tempfiles

<dbaplusplus_at_hotmail.com> wrote in message news:1122846842.271645.122980_at_g47g2000cwa.googlegroups.com...
> Oracle database 9.2.0.5 or 10.1.0.3
> Platforms - Windows 2000 or HP UNIX 11i
>
> When I do a RMAN database backup, I do not see tempfiles backed up.
> Only database files are backed up and shown in RMAN backup log.
>
> When I do a full restore of database, I do not see tempfile restored
> (not shown in log), yet I know sometimes tempfile gets
> created (looking at v$tempfile). However, some of my older backups, I
> have seen tempfile does not get recreated and I have to create it
> myself after restore.
>
> Is creation of tempfile version dependent (10g vs 9i)? Will appreciate
> clarfification on it.
>
> Yes, I have read RMAN manuals.
>
>
> Thanks.
>

Let me try to answer before you're immediately remanded to the documentation.

To my knowledge, RMAN does not explicitly recreate temp files. You have to recreate them yourself if the control file was restored and or the temp files were missing or damaged.
Note: RMAN does not backup tempfiles because there's nothing of value there to backup. :-D It's like deleting everything in the /tmp directory on a UNIX machine as the last action before shutdown or restart.

Here is an interesting link regarding RMAN (supplimental reading)

http://www.oracle-base.com/articles/9i/RecoveryManager(RMAN)9i.php

This link has this interesting note:
 NOTE: Tempfiles are automatically excluded from RMAN backups. This requires them to be re-added at recovery time.
There is an enhancement, 1641989, requesting RMAN take care of these tempfiles in the future.

http://www.idevelopment.info/data/Oracle/DBA_tips/RMAN_9i/RMAN9_12.shtml

But don't believe everything you read on the web, though. ;)

Rule of thumb:

If the control file was restored and or the temp file(s) are missing/damaged then recreate the temp files.
If you're restoring a database onto a separate machine using RMAN, create new temp files.

WARNING: DO NOT DO THIS ON A PRODUCTION VERSION Do a control test to verify this in both of your versions

Backup the database.
Restore the database.

Backup the database (including the control file). Delete the control file
Restore the database

Backup the database
Delete the tempfiles
Restore the database.

Backup the database (including the control file). Delete the control files and the tempfiles. Restore the database.

Backup the database (including the control file) Restore the database onto a completely separate and clean machine.

In each of these scenarios, examping the status of your temp files. Were they automagically recreated or did you have to recreate them yourself to fully restore the database?

Let me know your results.

From my 9i RAC class at the Oracle University I've learned that the Oracle development team integrates functionality that doesn't get documented. For example, and this came straight from teacher (20+ years experience in databases):
The teacher has heard and witnessed the control file being automatically backed up when doing a user managed backup.

So it very may well be that RMAN automatically restores TEMP files, but again, don't believe everything you hear until you try it for yourself.

Hope this helps.

-- 

Andreas Sheriff
Oracle 9i Certified Professional
Oracle 10g Certified Professional
Oracle 9i Certified PL/SQL Developer
----
"If you don't eat your meat, you cannot have any pudding.
"How can you have any pudding, if you don't eat your meat?"

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