就是一个储存了记录集状态的变量.
这是sas的解释.
Observation states are stored in a special variable _OBSTAT_ that is automatically read in the next time you open the data set. Thus, if you have colored, marked, hidden, excluded, and labeled observations, you can save all these states, exit SAS/INSIGHT software, and invoke SAS/INSIGHT software again later without losing your work. You can also set the values of the _OBSTAT_ variable to initialize observation states.

受教了~非常感谢！

thx for sharing