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Undo Tablespaces [Oracle]

Undo tablespaces are new with Oracle 9i.
Undo Segments can be handled by Oracle. The init params undo_management and undo_suppress_errors must be set in order to use undo tablespaces.
undo_retention specifies for how many seconds undo information is kept.

Monitoring of Undo tablespaces

v$undostat shows undo space consumption, transaction concurrency, and length of queries executed in the instance