When you assign a SAS
library that is not currently assigned within the SAS session, if
the engine is not specified on the assignment request, then SAS has
to determine which engine to use to process the library. If the library
already exists, and if its engine format can be determined, then SAS
uses the newest engine that is compatible with the format of the library.
Otherwise, if the engine format of the library cannot be determined,
then SAS selects an engine to use by default. If the assignment request
specifies a device or type of library that supports random access,
then SAS uses the engine that is specified by the ENGINE system option.
Otherwise, SAS uses the engine that is specified by the SEQENGINE
option.
The ENGINE option supplies
the default value when the library assignment specification refers
to one of the following conditions:
-
a
z/OS data set on disk that is
not cataloged
-
an empty
z/OS disk data set with
DSORG=PS specified and for which RECFM=U is not specified.
-
A UFS directory that contains members
of multiple engine formats that are different