一、mapjoin1.Mapper类packagecom.css.mapjoin;importjava.io.BufferedReader;importjava.io.FileInputStream;importjava.io.IOException;importjava.io.InputStreamReader;im...

https://blog.csdn.net/qq_17776287/article/details/78567514...

1. mapjoin优化适合小表join大表sethive.optimize.skewjoin=true;//有数据倾斜时开启负载均衡，默认falsesethive.auto.convert.join=true;//设置自动选择MapJoin，默认是truesethive.auto.convert.join....