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Re: how can i increase rollback segments simultaneously??

From: Jurij Modic <jmodic_at_src.si>
Date: Wed, 30 Dec 1998 22:18:51 GMT
Message-ID: <368a8476.8666158@news.siol.net>


On 30 Dec 1998 16:44:48 GMT, sweh_at_mpn.com (Stephen Harris) wrote:

>Piotr Kolodziej (pkol_at_otago.gda.pl) wrote:
>: Stephen Harris wrote in message <76bknd$12b$1_at_nebula.mpn.com>...
>: >careful with thos though - if your database crashes while the largeroll is
>: >online you may not be able to perform instance recovery properly...
>
>
>: Why ? Could you tell us ...
>
>As I understand it (and I may be wrong....) this is because largeroll is
>not listed in the init.ora file as being initially online, so the instance
>recovery will be unable to find some of the rollback information required
>to rollback incomplete transactions, after having replayed the redo logs.
>
>Simple fix is to add largeroll to the list of rollback segments in the
>init.ora file, startup the database (which will now correctly perform
>instance recovery), take the largeroll offline, shutdown the database
>(cleanly!) and then remove largeroll from init.ora again.
>
>Note: this has only happened to me once before, so I may be wrong about
>this :-)

Indeed, I belive your assumption is not correct. I made some tests, aborting an instance with uncommited transactions in a rollback segment that is not automaticaly put online at database startup, but the instance recovery never failed.

I belive Oracle temporaryly puts this "nonstandard" rollback segments online while performing instance recovery, if they contain any transactions that should be rolled back during instance recovery's rollback phase. After instance recovery is completed, those rollback segments are brought offline again.

>rgds
>Stephen

Regards,

Jurij Modic <jmodic_at_src.si>
Certified Oracle7 DBA (OCP)



The above opinions are mine and do not represent any official standpoints of my employer Received on Wed Dec 30 1998 - 16:18:51 CST

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