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RE: Good technical documents/references on tuning restores

From: April Wells <>
Date: Wed, 04 Jun 2003 08:59:49 -0800
Message-ID: <>

I had that problem in a AIX4.3.3 to AIX 5L upgrade... missing with really weird names... if you look at your tablespace sizes, the ones that are 0 bytes are the ones that have the missing files. If you can figure out what files go with those tablespaces, shutdown the database, "fix" the create control file script so those files are in it (if those tablespaces and files are still valid in the database)... and startup nomount and run the script again... it will tell you that you have those datafiles needing media recovery.  

recover datafile '<fully qualified datafile name>'  

If the tablespaces and files aren't valid anymore, you can offline drop them and they won't be in the data dictionary OR in the control file...    

April Wells
Oracle DBA/Oracle Apps DBA
Corporate Systems
Amarillo Texas

You will recognize your own path when you come upon it, because you will suddenly have all the energy and imagination you will ever need.

~ Jerry Gillies ~

-----Original Message-----

Sent: Wednesday, June 04, 2003 11:05 AM
To: Multiple recipients of list ORACLE-L

Have you tried backing up your controlfile to trace, editing the trace file to get rid of the unwanted datafiles, and reopening the database with the new edited controlfile? That should get rid of them. Of course, to a backup immediately after this.  

Good luck,


IIRC 'MISSING' means it is in the data dictionary, but not the control file. I've gotten that before, but haven't played that game in a while. You might be able to 'DROP' them, but I'm not sure. Check that first on a mini-test system.  


-----Original Message-----

[]On Behalf Of Sent: Tuesday, June 03, 2003 11:05 PM
To: Multiple recipients of list ORACLE-L


Database open and I wanted to not restore and not reference certain index and materia. view datafiles. Now the datafiles show up with weird MISSING...... names. How do I clean this up?  


-----Original Message-----

Sent: Tuesday, June 03, 2003 10:20 PM
To: Multiple recipients of list ORACLE-L


looking at v$backup_async_io found some datafiles where

        active bytes per sec            long-waits 
       2154608                          297   
         7489829                                297  

How can I start finding the disparity?

-----Original Message-----

Sent: Tuesday, June 03, 2003 9:05 PM
To: Stankus, Paula G; ''

Did I say that throughout this restore/recovery process my tapes being mounted and unmounted while other database backups and cloning was occurring. Big duh - this has got to be slowing down the process. Any ideas on how to handle this? Perhaps more than one tape subsystem would be better or while doing restores other backup utility is halted - hmmm - but that risks those other systems? How can I sell that? Hmmmm. Maybe I will first backup to disk. Yep, one backup to disk. Yep.....

-----Original Message-----

Sent: Tuesday, June 03, 2003 9:00 PM
To: Stankus, Paula G; ''

See nwadmin shows parellism = 32. I am not the tape person - that is my sys admin. I don't believe they actually have 32 tapes involved only 4. Can this impact performance by setting this too high? I also notice one backup server for networker with nwadmin messages like "clone sets being created...", "other databases being backed up". What is the usual policy on concurrently running backups, cloning at the same time recovery is taking place. It appears to show a lot of media waiting events: waiting for dlt7000 tape ... of the tapes that I specifically need for this restore. Did I say: I love my admin...I love my admin....I love my admin...

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:53 PM
To: Stankus, Paula G; ''

Okay, almost 4 minutes for a datafile that was 78168 blocks - how do I know if this is reasonable?

Also, seems to write these files out (restore sychron.) why can't it restore different datafiles in parallel? - stupid question huh?

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:46 PM
To: Stankus, Paula G; ''

SELECT SID, SERIAL#, CONTEXT,                            
 ROUND(SOFAR/TOTALWORK*100,2) "% complete",              
SUBSTR(TO_CHAR(SYSDATE,'HH24:MI:SS'),1,15) "Time now"    
FROM V$SESSION_LONGOPS                                   
WHERE OPNAME like '%restore%';                           
showed all 100% complete but msglog from RMAN shows it is truly still running.

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:40 PM
To: Stankus, Paula G; ''

Also found on monitoring performance of RMAN jobs: Note:144640.1 on Metalink

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:36 PM
To: Stankus, Paula G; ''

Found this white paper: <>

Anything better?

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:33 PM
To: Stankus, Paula G; ''

This is what I have set on my target database:

Version database and RMAN catalog - 32 bit Networker MML
Using RAID 1+0
Solaris 2.8

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:28 PM
To: Stankus, Paula G; ''

Okay - from my reading you don't need to have multiple tape io slaves if you are using asynch. I/O. Again, best document for perf. tuning database restores using RMAN would make mucho difference. Read old note about someone doing an analyze on the RMAN catalog tables to improve performance of restore. I think it has something to do with how quickly it finds the file on tape and writes to disk.

-----Original Message-----

Sent: Tuesday, June 03, 2003 8:25 PM
To: ''

Seems to be taking awfully long to read files from tape and write to disk. I allocate multiple tape channels like I do for the backup which only takes about 45 minutes. Does not seem to be spawning multiple sessions. Do I need to change parameters on my init.ora file to use multiple tape io slaves to see this. Anyway, would like notes/docs., references if you all have some.


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Author: April Wells

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Received on Wed Jun 04 2003 - 11:59:49 CDT

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