Usually, you do not have to specify an engine. If you
do not specify an engine, SAS automatically assigns one based on the
contents of the SAS library.
Even though SAS automatically
assigns an engine based on the library contents, it is more efficient
for you to specify the engine. In some operating environments, in
order to determine the contents of a library, SAS must perform extra
processing steps by looking at all of the files in the directory until
it has enough information to determine which engine to use.
For example, if you
explicitly specify the engine name as in the following LIBNAME statement,
SAS does not need to determine which engine to use:
libname mylib v9 'SAS-library';
In order to use some
engines, you must specify the engine name. For example, in order to
use engines like the XML engine or the metadata engine, specify the
engine name and specify specific arguments and options for that engine.
For example, the following LIBNAME statement specifies the XML engine
in order to import or export an XML document:
libname myxml xml 'c:\Myfiles\XML\Myxmlfile.xml' xmltype=generic;
You can specify an engine
name in the LIBNAME statement, the ENGINE= system option, and in the
New Library window.