多选题Which two statements are true regarding undo tablespaces（）AThe database can have more than one undo tablespace.BThe UNDO_TABLESPACE parameter is valid in both automatic andmanualundo management.CUndo segments automatically grow and shrink as needed， ac
题目
多选题
Which two statements are true regarding undo tablespaces（）
A
The database can have more than one undo tablespace.
B
The UNDO_TABLESPACE parameter is valid in both automatic andmanualundo management.
C
Undo segments automatically grow and shrink as needed， acting as circular storage buffer for their assigned transactions.
D
An undotablespaceis automatically created if the UNDO_TABLESPACEparameter is not set and the UNDO_MANAGEMENT parameter is set to AUTO during the database instance start up.