我有一个关于运行 hadoop mapreduce 作业的问题。我有一个表工作人员，按加入日期划分。创建这样的语句：
创建由 (join_date string) 分区的表人员 (id int, age int) 以“\;”结尾的行格式分隔字段；
我将一些数据放入分区'20130921'然后当我执行下面的语句时，结果是好的：
select count(*) from staff where join_date='20130921';**
但是当我在分区“20130922”（没有数据的分区）上执行时，map reduce 作业挂起的时间太长，似乎永远运行：
hive> select count(*) from staff where join_date='20130922';**
Total MapReduce jobs = 1**
Launching Job 1 out of 1**
**Number of reduce tasks determined at compile time: 1**
**In order to change the average load for a reducer (in bytes):**
set hive.exec.reducers.bytes.per.reducer=<number>**
**In order to limit the maximum number of reducers:**
set hive.exec.reducers.max=<number>**
**In order to set a constant number of reducers:**
set mapred.reduce.tasks=<number>**
**Starting Job** = `job_201309231116_0131, Tracking URL = ....jobid=job_201309231116_0131`
**Kill Command** = `/u01/hadoop-0.20.203.0/bin/../bin/hadoop job -kill job_201309231116_0131`
Hadoop job information for Stage-1: number of mappers: 0; number of reducers: 1
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
jobtracker 显示减少任务挂起，这项工作似乎无法完成。
我使用 hadoop-0.20.203.0 和 hive-0.10.0。我google了一整天，但没有发现任何主题有同样的问题，请帮助我。
此致。