Hive map-reduce查询失败

Question

我正在尝试运行我的第一个可以启动map-reduce作业的Hive查询。我已按照“http://doc.mapr.com/display/MapR/Hive”中的所有步骤进行操作。

“web_log”表已经完成，数据加载完成且没有错误。 但是当试图执行“SELECT web_log.FROM web_log WHERE web_log.url LIKE'％doc'*”时，我得到了以下异常。

Number of reduce tasks is set to 0 since there's no reduce operator Starting Job = job_1429420954627_0002, 
Tracking URL = http://yarn-training:8088/proxy/application_1429420954627_0002/ 
Kill Command = /opt/mapr/bin/hadoop job -kill job_1429420954627_0002 Hadoop job information for Stage-1: number of mappers: 0; number of reducers: 0 2015-04-19 00:19:15,690 Stage-1 map = 0%, reduce = 0% Ended Job = job_1429420954627_0002 with errors Error during job, obtaining debugging information... FAILED: 
Hi

请有人指导我。

Answer 1

你的减速器数量= 0，因为你的工作只是地图工作。现在这是你的查询??我认为你的select语句缺少一些东西。

SELECT web_log.* FROM web_log WHERE web_log.url LIKE '%doc';