Examine the parameters for a database instance:
NAME TYPE VALUE
temp_undo_enabled boolean TRUE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBSl
Your database has three undo tablespaces and the default undo tablespace is not autoextensible. Resumable space allocation is not enabled for any sessions in the database instance.
What is the effect on new transactions when all undo space in the default undo tablespace is in use by active transactions?
A. Transactions write their undo in the system undo segment.
B. Transactions wait until space becomes available in undotbs1.
C. Transactions write their undo in a temporary tablespace.
D. Transactions fail.
Answer: D
【解析】
UNDO表空间中，活动事务使用的空间是不能够被覆写的。如果UNDO表空间空间满，无法覆写时，新的事务无法分配UNDO空间，因此会失败。