SAS Libraries

Definition of a SAS Library

The logical concept of a SAS library remains constant, regardless of the operating environment. In any operating environment where SAS can be installed, the structure for organizing, locating, and managing SAS files is the same.

At the operating environment level, however, a SAS library has different physical implementations. Most SAS libraries implement the storage of files in a manner similar to the way the operating environment stores and accesses files.

For example, in directory-based operating environments, a SAS library is a group of SAS files that are stored in the same directory and accessed by the same engine. Other files can be stored in the directory, but only the files with file extensions that are assigned by SAS are recognized as part of the SAS library. Under OS/390 or z/OS, a SAS library can be implemented as either a bound library in a traditional OS data set or as a directory under UNIX System Services.

SAS files can be any of the following file types:

SAS data set (SAS data file or SAS view)
SAS catalog
stored compiled SAS program
SAS utility file
access descriptors
multi-dimensional database files such as MDDB, FDB, and DMDB files
item store files

Types of Files in a SAS Library

[Types of Files in a SAS Data Library]

Each SAS file, in turn, stores information in smaller units that are characteristic of the SAS file type. For example, SAS data sets store information as variables and observations, while SAS catalogs store information in units called entries. SAS determines the type of a file from the context of the SAS program in which the file is created or specified; therefore, a library can contain files with the same name but with different member types.

SAS libraries can contain files that you create, or they can be one of several special libraries that SAS provides for convenience, support, and customizing capability such as the WORK library. SAS does not limit the number of SAS files you can store in a SAS library.

Top of Page