SAS Libraries
Definition
A SAS library contains
one or more files that are defined, recognized, and accessible by
SAS, and that are referenced and stored as a unit. One special type
of file is called a catalog. In SAS libraries,
catalogs function much like subfolders for grouping other members.
Predefined SAS Libraries
By default, SAS defines several libraries for you:
Sashelp
a permanent library
that contains sample data and other files that control how SAS works
at your site. This is a Read-Only library.
Sasuser
a permanent library
that contains SAS files in the Profile catalog and that stores your
personal settings. This is also a convenient place to store your own
files.
Work
a temporary library
for files that do not need to be saved from session to session.
You can also define additional libraries. When you define
a library, you indicate the location of your SAS files to SAS. After
you define a library, you can manage SAS files within it.
Note: If you are using SAS Studio,
you might encounter the Webwork library. Webwork is the default output
library in interactive mode. For more information about the Webwork
library, see SAS Studio: User’s Guide.
Defining Libraries
To define a library, you assign a library name to it
and specify the location of the files, such as a directory path.
You can also specify
an engine, which is a set of internal instructions that SAS uses for
writing to and reading from files in a library.
You can define SAS libraries
using programming statements. For information about how to write LIBNAME
statements to define SAS libraries, see Assigning
Librefs.
Tip
Depending on your operating
environment and the SAS/ACCESS products that you license, you can
create libraries with various engines. Each engine enables you to
read a different file format, including file formats from other software
vendors.
When you delete a SAS library, the pointer to the library
is deleted, and SAS no longer has access to the library. However,
the contents of the library still exist in your operating environment.
How SAS Files Are Stored
A SAS library is the highest level of organization for
information within SAS.
For example, in the Windows and UNIX environments, a
library is typically a group of SAS files in the same folder or directory.
The table below summarizes
the implementation of SAS libraries in various operating environments.
|
Environment
|
Library Definition
|
|---|---|
|
Windows, UNIX
|
a group of SAS files
that are stored in the same directory. Other files can be stored in
the directory, but only the files that have SAS file extensions are
recognized as part of the SAS library.
|
|
z/OS
|
a specially formatted
host data set in which only SAS files are stored.
|
Storing Files Temporarily or Permanently
Depending on the library
name that you use when you create a file, you can store SAS files
temporarily or permanently.
|
Temporary SAS libraries
last only for the current SAS session.
|
If you do not specify
a library name when you create a file, the file is stored in the temporary
SAS library, Work. If you specify the library name Work, then the
file is stored in the temporary SAS library. When you end the session,
the temporary library and all of its files are deleted.
|
|
Permanent SAS libraries
are available to you during subsequent SAS sessions.
|
To store files permanently
in a SAS library, specify a library name other than the default library
name Work.
In the example, when
you specify the library name Cert when you create a file, you are
specifying that the file is to be stored in a permanent SAS library.
|
Last updated: August 23, 2018
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