Hi, I have two tables with 8 buckets each on the same key and want to join them. I ran "explain extended" and get the plan produced by HIVE which shows that a map-side join is a possible plan.
I then set in my script the hive.optimize.bucketmapjoin option to true and reran the "explain extended" query. I get the exact same plans as output. I ran the query with and without the bucketmapjoin optimization and saw no difference in the running time. I have the following questions: 1. Should I see sth different in the explain extended output if I set and unset the hive.optimize.bucketmapjoin option? 2. Should I see something different in the output of hive while running the query if again I set and unset the hive.optimize.bucketmapjoin? 3. Is it possible that even though I set bucketmapjoin to true, Hive will still perform a normal map-side join for some reason? How can I check if this has actually happened? Thanks, Avrilia
