Chamal,
I believe the "alternative approach" implied here is simply use of a single-column primary key. There is further discussion in:
http://www.hibernate.org/hib_docs/reference/en/html/components.html#components-compositeid
I've used composite-id tags in my mapping files without issue. Updates are less efficient. However, upating does seem to work for me. I'm using the "separate class" approach described by the hibernate team.
If your table is just a read-only table, you probably won't have a problem.