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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Re[1] : Recovery Scenarios - Help !!
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Prem Khanna J wrote:
>Hi Peter , thanx a lot for ur reply.=20
> =20
>
>>>Case 1
>>>------
>>> =20
>>>
>>If you lose the undo tablespace the instance will crash, after the rec=
overy of the undo tablespace
>>(asuming that you hae a backup and can appliy archive and redologs) >wh=
en the database starts it
>>will do instance recovery and rollback all uncommited transactions.
>> =20
>>
>
>When UNDO tablespace is lost , where from does oracle get=20
>the information to rollback ? This is not very clear to me.
>
> =20
>
You restore the undo tablespace files from a backup and apply redologs=20
this will rebuild the undo tablespace and the information
that is needed for rollback of uncommetted transactions
>>>Case 2
>>>------
>>>I have lost my temp tablespace during a batch job which does lot of so=
rt/update.
>>>- What will be the status of my batch job and how do i recover by tem=
p tablespace now ?
>>> =20
>>>
>
> =20
>
>>This depends on the way you have written the batch program :
>>1) If the batch program detects the problem and issues a rollback o=
f the last uncommitted transaction and stops you don't
>> have a problem :-)
>>2) If the batch program just quits on error then Pmon will do the r=
ollback of the uncommitted transaction.
>> =20
>>
>
>
>So anyway , the transaction will be rolled back and=20
>i'm safe . am i right ?
> =20
>
Since you still have the undo tablespace PMON is able to rollback the=20
uncommitted transactions, this assumes that your batch program has
logic to restart after a crash :-)
> =20
>
>>>Case 3
>>>------
>>>I have lost an un-archived online redo log file.The proper recovery pr=
ocedure is :
>>>- restore all datafiles from backup
>>>- mount the database
>>>- recover until cancel
>>>- open resetlogs
>>>
>>>Without restoring datafiles from backup,Can i do this :=20
>>>- mount the database
>>>- recover until cancel
>>>- open resetlogs
>>> =20
>>>
>
>when i recover/resetlogs without restoring the
>datafiles from backup , the database will be inconsistent
>state ... am i right ?
>
> =20
>
You will not be able to open the database since the current redolog is=20
missing.
You can get more infomation on Oracle and revovery from *Oracle9/i/=20 Backup and Recovery Concepts Release 2 (9.2),*
*Chapter 3 Recovery Principles* **** **/peter **
>Thanks and Regards,
>Prem.
>
>--
>http://www.freelists.org/webpage/oracle-l
>
> =20
>
--=20
Best regards / Venlig hilsen
/*Peter Gram*/
Miracle A/S <http://www.miracleas.dk>
Kratvej 2
DK - 2760 M=E5l=F8v
Cell: (+45) 2527 7107 Phone: (+45) 4466 8855 Fax: (+45) 4466 8856 Home: (+45) 3874 5696
22-24 Nov 2004 RMAN-kursus med Tuomas Pystynen=20 17-19 Jan 2005 Miracle Master Class with Tim Gorman=20 28 feb - 2.mar 2005 Database Master Class with Chris Date=20 2-4 May 2005 SQL Server Master Class with Kimberly Tripp=20
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Nov 29 2004 - 09:07:38 CST
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