Re: Question on hive.merge.nway.joins,

Hi Okumin, I agree that setting hive.merge.nway.joins to true (or false) can have both positive and negative effects on the performance, depending on the query and other related configuration parameters. I thought the default value was set to false for some correctness issue (for example, mapjoin_

Re: Question on hive.merge.nway.joins,

Hi Sungwoo, I have totally no idea why we changed the default value. I'm just sharing my knowledge and experience. First, I know there is a known issue when we use it with Tez. We can see the following statement on the official website

Question on hive.merge.nway.joins,

Hello, In HIVE-21189 [1], the default value for hive.merge.nway.joins is set to false. There is no record of why it was set to false, and I would like to understand the background for the decision. Specifically I wonder if the following situation is relevant to the decision. Example) MapJoinOp_1