SAS
libraries are generally stored as permanent data libraries. However,
SAS provides a temporary or scratch library where you can store files
for the duration of a SAS session or job.
A permanent SAS library
is one that resides on the external storage medium of your computer
and is not deleted when the SAS session terminates. Permanent SAS
libraries are stored until you delete them. The library is available
for processing in subsequent SAS sessions. When working with files
in a permanent SAS library, you generally specify a libref as the
first part of a two-level SAS filename. The libref tells SAS where
to find or store the file.
Note: You can also skip using a
libref and point directly to the file that you want to use, using
syntax that your operating system understands. An example of this
in the Windows environment is
data 'C:\root\sasfiles\myfile.ext';
Operating Environment Information: Files are specified differently in various operating environments.
See the SAS documentation for your operating environment for more
information.
A temporary SAS library
is one that exists only for the current SAS session or job. SAS files
that are created during the session or job are held in a special work
space that might or might not be an external storage medium. This
work space is generally assigned the default libref WORK. Files in
the temporary WORK library can be used in any DATA step or SAS procedure
during the SAS session, but they are typically not available for subsequent
SAS sessions. Normally, you specify that data sets be stored in or
retrieved from this library by specifying a one-level name. Files
held in the WORK library are deleted at the end of the SAS session
if it ends normally.
There are a number of
SAS system options that enable you to customize the way you name and
work with your permanent and temporary SAS libraries. See the USER=,
WORK=, WORKINIT, and WORKTERM system options in
SAS System Options: Reference for more information.