I thought that I had commented this when I opened this ticket 2 years ago, but it seems that I didn't. For all this time I've been using SUBSELECTs as a workaround for this problem. They're not as much elegant as OUTER LEFT JOINs. Nor they perform so well, unless the DB query planner it's able to detect these usages and transform them in effective OUTER LEFT JOINs (improbable). But they do their job.

The only exception are those cases in which you need two or more columns from the sub-selected table, because the SUBSELECT retrieves only one. In these cases you've to do dirty things like repeating the SUBSELECT several times... And lose more performance, again.

I'm still shocked that there aren't more people voting for this ticket :S . Because there are many queries affected by this problem. I guess that it's because they've alternatives, such as using native SQL. But still I believe that it would be great to have it solved in HQL.