Building a permanent SAS data set
Building a data set is relatively expensive. Generally speaking, you should build your data set in one SAS job and analyze them in other jobs. It makes little sense to rebuild a data set every time you want to do a particular analysis task. How do you build a SAS data set that will stay around for later use.
There are two components to building a permanent data set:

• Tell SAS where the directory is that you want to put the file into.
• Put the file in the directory.

The way you do this is:

• Define the data library called LIBRARY.
• Use a two-level name in a step that outputs a data set.