Well, AFAIK HQL is transformed into DB specific SQL, so knowing that something is not supported maybe it would be possible to translate such HQL into better SQL.

In general this is not a major issue, but when it comes to portability it causes some problems. I had an application that was expected to work both MySQL and SQL Server. AFAIK HQL was designed to provide portability thanks to the fact that it is not specific to any database and is translated into DB specific SQL. But in this case, if I use such HQL query it works under MySQL, but doesn't under SQL Server, so assumed portability gets lost. This is why I've filed it as an issue for possible improvement.

I've ended up with workaround described above at a cost of efficiency.