The system procedure, dbo.sa_external_library_unload, can be used to unload an external library when the library is not in use. The procedure takes one optional parameter, a long varchar. The parameter specifies the name of the library to be unloaded. If no parameter is specified, all external libraries not in use will be unloaded.

The following example unloads an external function library.

call sa_external_library_unload('library.dll')

This function is useful when developing a set of external functions because you do not have to shut down the database server to install a newer version of the library.