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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Specify Rollback for an Export
Erik - The problem lies not with your export but with the other
transactions. Basically, export is taking a query of the table when it
starts (like a select * with no where clause). As it is exporting the table,
other applications are making changes to the table. These changes are held
in the rollback segments, but when the transaction that caused the changes
commits, eventually Oracle releases these. In your case, before the export
reaches the end of the table, it tries to retrieve a block, learns it is
changed, checks the rollback segments, learns it has been released, then
reports an error that it cannot recreate the block as it existed when the
export began.
The best choice is to perform your export when the table isn't being changed so much, i.e.. not when batch jobs are hammering the table. Second choice would be to create a second set of larger rollback segments and switch usage to them. Third choice available on 9i is to use automatic undo, which has a target parameter of how long in time to hang onto changed blocks.
Dennis Williams
DBA, 40%OCP
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Friday, October 18, 2002 9:14 AM
To: Multiple recipients of list ORACLE-L
I am performing an export of a set of very large tables. I am not using CONSISTENT mode. The exports are failing due to snapshot too old errors. The application uses many small rollback segments, but has one large one for big transactions. Is it possible to force the export to use the large segment without taking all the others (except System) offline? I have seen this question asked on the list before, but did not find a definitive follow-up answer.
Thanks
Erik
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Erik Williams
INET: ewilliams_at_brownco.com
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Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Fri Oct 18 2002 - 10:43:54 CDT
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