Re: Question about bushy join in hive CBO

Hi Rossi, Historically, we used LoptOptimizeJoinRule of Calcite to do join reordering. This does a greedy search on join order search space to find a join order which is atleast as good as original join order of query. Goodness being in term of estimated cost and not globally optimal because of

Re: Question about bushy join in hive CBO

Thank you, Ashutosh. That's very informative. I appreciate that! *Rossi* 2015-05-12 9:08 GMT+08:00 Ashutosh Chauhan hashut...@apache.org: Hi Rossi, Historically, we used LoptOptimizeJoinRule of Calcite to do join reordering. This does a greedy search on join order search space to find a

Question about bushy join in hive CBO

Hi all, I'm studying CBO code in hive. I have a question about bushy join optimization. Bushy join did get introduced in hive via HIVE-7577 https://issues.apache.org/jira/browse/HIVE-7577, and played an important role in optimizing several queries in TPCDS benchmark. Somehow I saw the bushy join