ubuntu - hadoop 0.20.2-cdh3u0 - hive 0.8.1
Okay first off; I know JOIN + LATERAL VIEW together isn't working so I moved my JOIN into a subquery and that makes the query work properly
However when I added a MAPJOIN hint for the JOIN in the subquery it will also stop doing the reducer for the main query!
This only happens when there's a LATERAL VIEW in there though, if I remove the LATERAL VIEW then the main query still get's a reducer to do grouping
Here's a gist: https://gist.github.com/2499436 Containing the queries and a PHP script which you can run to execute the test case I'm using, which does;
- setup a database called hive_mapjoin
- setup tables
- load some test data
- do the selects
You'll need the https://github.com/rcongiu/Hive-JSON-Serde/downloads json-serde-1.1-jar-with-dependencies.jar with it though and change the path
I guess looking at the queries you guys can probally figure out a better testcase, but maybe it's helpful
Not sure if this is a bug or me doing something that just isn't supposed to be working, but I can't seem to find any pointers that this wouldn't be supported...
Here's another gist with the plan.xml: https://gist.github.com/2499658