Have you ever thought? What happens after you de-activate or remove a plugin? Actually, every plugin create some reference entries in WordPress blog database, and when you de-activate or removes a plugin, those entries are left orphaned in wp_options table in your blog database. That’re of no use, but only cluttering and overloading your db.
Clean Options is a WordPress plugin that lets you find orphaned options left by inactive / removed WordPress plugins and allows for their removal from the WordPress blog database.
The Clean Option plugin searches only PHP files in your blog's folders for get _ option('option _ name') and get _ settings('option _ name').
It finds orphaned options, that do not have any files that “get” their values. User can manually review and delete the orphaned options.