The stored compiled
macro facility compiles and saves compiled macros in a permanent catalog
in a library that you specify. This compilation occurs only once.
If the stored compiled macro is called in the current or later sessions,
the macro processor executes the compiled code.
In SAS 9.1.3 or higher,
the stored compiled macro catalog is initially opened for read-only
access. When a stored compiled macro is being compiled or updated,
the catalog is immediately closed and reopened for update access.
After the macro is compiled and the catalog has been updated or changed,
the catalog is again immediately closed and reopened for read-only
access.