--转载自  http://www.orafaq.net/maillist/oracle-l/2003/12/15/1191.htm
最近2天我的日志文件中出现了 SMON offlining US=## 这样的记录信息
我刚开始有些担心是数据库出了问题,经过查找发现是oracle AUM的功用:
This message will be quite common if you are using Automatic Undo Management (AUM). As additional undo segments are needed, they are created. After a period of inactivity, SMON will offline them. Do not fear, they will be onlined if needed.
I have a paper about AUM on my site at www.optimaldba.com/library.html. --这个地方没有详细内容!