Polybase: Forcing Predicate Pushdown

Update 2016-11-30:  I have completely rewritten this post on using external pushdown.  I'll leave this post up for posterity's sake, but you should read the new predicate pushdown post and not listen to any of the ravings of whichever madman wrote this work. Update 2016-11-08:  I ended up solving my predicate pushdown issue; it turns out…