-
library
engines
- support the SAS data library model. Library engines can
be classified as native or interface.
Native library engines are engines that read from or write
to files formatted by SAS only. Five native library engines are common to
all operating environments:
- base engine
- writes SAS data libraries to disk format. If you do not
specify an engine name on the LIBNAME statement when creating a new SAS data
library, SAS automatically selects this engine. The base engine is also automatically
selected if you are accessing existing SAS data sets on disk.
The base engine
- is the only engine that supports the full
functionality of the
SAS data set and the SAS data library.
- supports view engines.
- meets all the processing characteristics required by SAS
statements
and procedures.
- creates, maintains, and uses indexes.
- reads and writes compressed (variable-length) observations. SAS
data sets created by other engines have fixed-length observations.
- assigns a permanent buffer size to data sets and temporarily assigns
the number of buffers to be used when processing them.
- repairs damaged SAS data sets, indexes, and catalogs.
- enforces
integrity constraints, creates backup files and creates
audit trails.
- remote engine
- allows access to data across SAS session boundaries and
across operating environment boundaries.
- compatibility engine
- enables you to access SAS data sets that were created by
older versions of SAS without converting them. SAS determines whether the
library is stored in disk or tape format, and automatically reads from and
writes to the library in the correct format.
- sequential engine
- uses a simpler format to access files on storage media that
do not allow random access methods, for example, tape or sequential format
on disk.
- transport engine
- enables moving your SAS data sets from one operating environment
to another and from one release to
another.
Operating Environment Information: In
some operating environments, one compatibility engine reads both disk and
tape. Other operating environments have two separate compatibility engines-one
for each storage medium. See the SAS documentation for your operating environment
for the engine names and examples for using them. ![[cautionend]](../common/images/cautend.gif)
|
| Interface Library Engines |
Interface library engines read from files formatted by
other software.
- SPSS
- reads SPSS Release 9 files and SPSS-X files in either compressed
or uncompressed format. The engine can also read the SPSS Portable File Format,
which is analogous to the transport format for SAS data sets.
- OSIRIS
- reads OSIRIS data and dictionary files in EBCDIC format.
- BMDP
- reads BMDP save files.
Interface view engines are supported by SAS/ACCESS software.
These engines enable you to read and write data directly to and from files
formatted by a database management system (DBMS), such as DB2 and ORACLE.
Interface view engines enable you to use SAS procedures and program statements
to process data values stored in these files without the cost of converting
and storing them in files formatted by SAS. Contact your SAS software representative
for a list of the SAS/ACCESS interfaces available at your site. For more information
about SAS/ACCESS features, see Accessing Data in a DBMS
and the SAS/ACCESS documentation for your
DBMS.
Operating Environment Information: The
capabilities
and support of these engines vary depending on your operating environment.
See the SAS documentation for your operating environment for more complete
information.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
