Monthly Archives: March, 2015

The Importance of DBA_ROLLBACK_SEGS – 2 of 3

Yes, the original post title said “The Importance of DBA_ROLLBACK_SEGS -1 of 2”.  The second part was supposed to be where I clobbered my undo tablespace and had to use _CORRUPTED_ROLLBACK_SEGMENTS.  Apparently I can’t even clobber my tablespaces right.  My evil plan was simple: Shut the database down Nuke the rollback segment datafile from orbit …

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The importance of DBA_ROLLBACK_SEGS – 1 of 2

Unless you have been a DBA for more than 10 years, you might not have even heard of DBA_ROLLBACK_SEGS. Back in the days of Oracle6 and Oracle7, when there was no Interwebs and every kid had to walk to school uphill both ways in the snow, Oracle had rollback segments. Before we had undo tablespaces, …

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Captain Smith’s Log

Everyone knows the story of the Titanic.  She hit an iceberg on her maiden voyage which ruptured 5 of her 16 watertight compartments.  Like a RAID array, her hull was designed with redundancy in mind, and could afford the failure of up to 4 of the compartments.  Unfortunately the collision damaged the 5 forward compartments, …

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