我是sas初学者，使用sas9.2，输入命令：libname resdat ('d:\resdat\resdat1','d:\resdat\resdat2');然后打开a库查看数据集a1属性，其包括4个观测，6个变量，但是一旦我接着输入程序data resdat.a1,log显示：NOTE: Data file RESDAT.A1.DATA is in a format that is native to another host, or the file encoding does not match the session encoding. Cross Environment Data Access will be used, which might require additional CPU resources and might reduce performance.NOTE: The data set RESDAT.A1 has 1 observations and 0 variables.这是怎么回事？谢谢解答！