Oracle® Database 10g Insider Solutions

Using Undo Advisor

Undo Advisor helps you to size the undo tablespace based on the workload history. By default, automatic undo retention tuning is enabled, and Oracle determines the optimal undo retention time depending on the undo tablespace size. Oracle Database 10g remembers these optimal undo settings and avoids any performance problems during instance restart, database migration, undo tablespace switching, and so on. After a database restart or undo tablespace switch, Oracle Database 10g determines the number of undo segments to be placed online based on data stored in the AWR. The Undo Advisor analyzes the undo usage over a period of time and suggests the optimal undo tablespace size to support the longest-running queries. Altering the ...