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Home -> Community -> Mailing Lists -> Oracle-L -> Re: dbv - Found block already marked corrupted
On 01/30/2004 03:46:04 PM, Tim Gorman wrote:
> One further question, though...
>
> >> Of course, if someone knows a utility to un-flag a block I'm all
> ears.
>
> Why would anyone want to "unflag" a block that has been flagged as
> corrupt?
> I'm all ears for that... :-)
>
> -Tim
Actually, not all corrupt blocks are the same. The definition of a corrupt block is "a block with a bad checksum". These bad checksums are mostly caused by software. I have a ton of experience with "corrupt blocks" which came into being after copying production database to development database using BCVs. This means hot backup and instance recovery. For the reasons of speed, the tables with the computed data were created with "NOLOGGING" attribute and when access was attempted in the cloned instance, oracle started screaming about "corrupted blocks". When the table was truncated and the data computed again, the "corruption" was gone. In other words, so called "corrupt blocks" can simply be flagged "honest" and reused, if they're empty.
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Fri Jan 30 2004 - 15:02:41 CST
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