On 6/7/12, Mark Grover <grover.markgro...@gmail.com> wrote: > Can you please check if predicate push down enabled changes the explain > plan on a simple inner join query like: > > select a.* from a inner join b on(a.key=b.key) where a.some_col=blah;
No problem, I ran following as you suggested (INNER JOIN didn't work for me, so I used just JOIN): create table a (key int, some_col string); create table b (key int, some_col string); set hive.optimize.ppd=true; explain select a.* from a join b on(a.key=b.key) where a.some_col='blah'; set hive.optimize.ppd=false; explain select a.* from a join b on(a.key=b.key) where a.some_col='blah'; There is a difference in the explains, the first one has a Filter operator on some_col, quite high in the tree. So I guess here it is working, although I still see another Filter operator in reduce deeper down in both, I'm not sure if that is correct or not, but I believe that it should be only executed once. I put the results at pastebin so you can see yourself: http://pastebin.com/gquMksqE and http://pastebin.com/0FPx7KKG. Jan
