646.View the exhibit and examine the TRANS table's storage information. After a massive delete
operation, you executed the following statement to shrink the TRANS table: SQL> ALTER TABLE trans
SHRINK SPACE CASCADE;
Which statement describes the outcome of the command?
A. An error is produced.
B. The table and all related objects are compacted and the position of the high-water mark (HWM) for the
table is adjusted
C. The table and related indexes are compacted but the position of the high-water mark (HWM) for the
table remains unchanged
D. The unused space in the table is reclaimed and returned to the tablespace and the data manipulation
language (DML) triggers on the table are fired during the shrinking process
Answer: B
答案解析：
参考：http://blog.csdn.net/rlhua/article/details/13431595
使用SHRINK SPACE子句可以收缩段中的空间。如果指定了CASCADE，则收缩行为将级联到所有支持收缩操作的从属段，但实体化视图、LOB 索引和IOT（索引表）映射表例外。