Each SAS
data library is associated with a SAS library engine. SAS library
engines are software components that form the interface between the SAS System
and the SAS data library. It is the SAS library engine that locates files
in a SAS data library and renders the file contents to SAS in a form that
it can recognize. Library engines perform such tasks as:
- reading and writing data
- listing the files in the
library
- deleting and renaming files.
SAS has a Multiple Engine Architecture that allows users
to read to and write from files in different formats. Each SAS engine has
specific processing characteristics, such as the ability to
- process a SAS file generated by an older version of
SAS
- read database files created by other software programs
- store and access files on disk or
tape
- determine how variables and observations are placed in a file
- place data into memory from its physical
location
- transport SAS files between operating environments.
A user is generally not aware of the particular type of engine
that is processing data for SAS at any given time. If the user issues a command
that is not supported by the engine, an error message is displayed in the
log.
More than one engine may be involved in processing a DATA step; for
example, one engine may be used to input data, and another engine may be used
to write observations to the output data set.
When needed, a user can select a specific engine to perform a task.
| Engine name |
Task |
| Remote |
via SAS server |
| V6 |
for V6 libraries |
| V7 |
for V7 libraries |
| V8 |
for V8 libraries (default) |
| BMDP |
for use with BMDP files |
| V6 tape |
for V6 libraries on tape |
| XPORT |
for reading data from a transport file |
|
|
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
