| SAS Companion for the OpenVMS Operating Environment |
It
is always more efficient to explicitly specify the engine name than to ask
the SAS System to determine which engine to use. To assign an engine name,
use a LIBNAME statement or LIBNAME function, or the LIBASSIGN command in the
command window. If you use the LIBASSIGN command the
Default engine--that is, BASE--is listed
in the
Engine: field of
the New Library dialog box; when you select [OK], you automatically
select this default engine.
If you do not assign an engine name, SAS looks at the OpenVMS file
types of the files that exist in the specified directory and uses the following
rules to determine which engine to assign:
- If the directory contains SAS data sets from only
one of the native library engines that are supported, then that engine is
assigned to the libref.
- If the directory contains no SAS data sets, then
the default engine is assigned to the libref. The default engine is determined
as follows:
- For SAS data libraries on disk, the default engine
is determined by the value of the ENGINE= system
option. By default, the ENGINE= system
option is set to V8. However, you can change the value of this system option
if you prefer to use a different engine as the default engine for disk libraries.
Other valid values are V7, V6, and CONCUR. For more information about the ENGINE= system
option, see ENGINE=
and SAS Language Reference: Dictionary.
- For sequential-format SAS data libraries (either
on tape or disk), the default engine is determined by the value of the SEQENGINE=
system option. By default, SEQENGINE= is
set to TAPE. The other valid values are V8TAPE, V7TAPE, and V6TAPE.
- A directory that contains SAS data sets from more
than one engine is called a mixed-mode library. The SAS System
assigns the default engine to mixed-mode libraries.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
