> > > > > > But other situations seem un-handle-able to me: > > > > SELECT remote_func1(l.x) FROM local_table l WHERE l.active = true; > > Do we have any way, or any plan to make a way, to push the set (SELECT > x FROM local_table WHERE active = true) to the remote side for > execution there? Obviously, there are foreign DBs that couldn't > support this, but I'm guessing they wouldn't have much by way of UDFs > either. >
No. The remote query has to be generated at planning time, so it can't make predicates out of anything that can't be resolved into constants by the planner itself. The complexities of doing so would be excessive, far better to let the application developer split the queries up because they know better which parts have to resolve first.
