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I want to delete a record from a table and no one should ever be able to recover the deleted data. I have done delete operation but the record is still in the undo segments. And one can do flashback and retrive that row.

marked as duplicate by Paul White, Nick Chammas, dezso, Max Vernon, Mark Storey-Smith Apr 18 '13 at 16:33

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  • yes, but it does not tell anything about the record in undo and redo segments – Neal Apr 17 '13 at 17:41
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    Define "ever". Are we allowed to recover deleted data by restoring from a year-old offsite backup tape? – Mike Sherrill 'Cat Recall' Apr 17 '13 at 17:53
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    Sounds like you're trying to hide something? – Kermit Apr 17 '13 at 20:04
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There is likely a more streamlined set of steps, but here is a start.

  • Delete the data out of any materialized views or home grown replication methods using triggers or the like.
  • Delete the data out of any database audit tables.
  • Change the database to noarchivelog.
  • Create a new undo tablespace.
  • Switch log files until all are archived.
  • Shutdown the database.
  • Turn off and purge any storage or virtual machine level snapshot capability.
  • Delete all trace files that may contain the data.
  • Delete all backups sets including archive log backups that could contain the data.
  • Delete all OS audit logs that could contain the data.
  • Visit any computer that may have the data cached or displayed and destroy it there.
  • Visit any other storage devices the data may have been copied to and purge those.
  • Find any hard copies of the data and destroy those.
  • If someone memorized the data, memory erasure is beyond the scope of this site.
  • Is this serious? I think the OP just wants to get rid of the bytes within the database files and logs. Related: forensically deleting/updating data But of course I'm being presumptious – 孔夫子 Apr 17 '13 at 20:28
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    I would also recommend to move the table to a new tablespace on a new disk drive and procedurally rewrite all the old disks. Else forensic analysis could probably retrieve the old data. Moving a table will only copy logically existing data. – Vincent Malgrat Apr 18 '13 at 9:58
  • @Vincent Malgrat - Indeed, and do the same procedural rewrite for all storage media that were storing backups, trace files, etc. – Leigh Riffel Apr 18 '13 at 12:41
  • It's incredible how Oracle gets in the way at every step to protect data =) – Vincent Malgrat Apr 18 '13 at 12:50
  • my boss is a weirdo. He doesnot know what he wants. I recommended him to move to a new tablespace, but it is not practical to do each and everytime. So i told him to use Virtual Private Database. Thanks all for your time and answers – Neal May 14 '13 at 10:59

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