One other new Oracle9i storage feature worth mentioning is the concept
of an UNDO tablespace. For years, Oracle DBAs have worked diligently to
have the proper rollback management structures in place to handle all
the "whoops" activity in their database.
Now, Oracle9i eases this burden by offering automatic management of
rollback functions through UNDO tablespaces. UNDO tablespaces can either
be created when the database is designed or built later. They are
implemented through the undo_management configuration parameter.
The idea behind automatic UNDO management is that Oracle controls how
many rollback segments are available for use, along with their size. The
desired goal is the elimination of rollback waits, extends, and other
performance-sapping problems.
