http://crackman.net/?p=633
The following SAS program is submitted:
options reuse=YES;
data SASUSER.REALESTATE(compress=CHAR);
set SASUSER.HOUSES;
run;
What is the effect of
the reuse=YES SAS system option?
A.
It allows updates in place.
B.
It tracks and recycles free space.
C.
It allows a permanently stored SAS
data set to be replaced.
D.
It allows users to access the same
SAS data set concurrently.


答案是：B
看看英文解释：
我的理解是这样的，这里是对数据集压缩后，多于的空间再次利用的问题，举个例子：现在家里面有一堆衣服在衣柜里面，我用压缩机把衣服......
见：http://crackman.net/?p=633