默认不支持分桶功能，需要开启。

set hive.enforce.bucketing;

+-------------------------------+--+
|              set              |
+-------------------------------+--+
| hive.enforce.bucketing=false  |
+-------------------------------+--+

执行开启：

set hive.enforce.bucketing = true;

+------------------------------+--+
|             set              |
+------------------------------+--+
| hive.enforce.bucketing=true  |
+------------------------------+--+

最终转为MapReduce，设置4桶：

set mapreduce.job.reduces = 4;

+--------------------------+--+
|           set            |
+--------------------------+--+
| mapreduce.job.reduces=4  |
+--------------------------+--+

创建分桶表

create table t1(id int, name string, age int, dept string)
clustered by(id)
into 4 buckets
row format delimited
fields terminated by ',';

导入数据：insert + select

insert overwrite table t1 select * from t2 cluster by(id);