The recommended way to "shrink" an undo tablespace in AUM is as others said, create a new one and assign undo_tablespace to it. If you work with Oracle support, they may allow you to set "_smu_debug_mode" to 4 and either shrink an undo segment, or offline and drop it. Just another option to keep in mind, even though it's probably more work. Yong Huang -- //www.freelists.org/webpage/oracle-l