Complex subset constraints do not result in any sql output. A simple Subset is considered to have all parts in starting the same "From" and ending in the same "To". Anything other than this, will not result in a corresponding output in sql. Not even mentioning of its absence, which is even worse.
Some DBMSs do not support database constraints, therefor sql trigger code needs to be generated. And still not all DBMSs support that either. So for those the log needs to mention the issue of lacking support.
