99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項選擇題

The UNDO_RETENTION parameter in your database is set to 1000 and undo retention is not guaranteed. Which statement regarding retention of undo data is correct？（）

A.Undo data becomes obsolete after 1，000 seconds.
B.Undo data gets refreshed after every 1，000 seconds.
C.Undo data will be stored permanently after 1，000 seconds.
D.Committed undo data would be retained for 1，000 seconds if free undo space is available.
E.Undo data will be retained in the UNDO tablespace for 1，000 seconds，then it gets moved to the TEMPORARY tablespace to provide read consistency.

微信掃碼免費搜題