当insert数据到表时抛出异常：
Diagnostic Messages for this Task:
Error: java.lang.RuntimeException: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.hive.ql.io.orc.OrcSerde$OrcSerdeRow
at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.reduce(ExecReducer.java:263)
at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:444)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:392)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:168)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1830)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
Caused by: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.hive.ql.io.orc.OrcSerde$OrcSerdeRow
at org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat$OrcRecordWriter.write(OrcOutputFormat.java:81)
at org.apache.hadoop.hive.ql.exec.FileSinkOperator.process(FileSinkOperator.java:753)
at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:839)
at org.apache.hadoop.hive.ql.exec.SelectOperator.process(SelectOperator.java:88)
at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:839)
at org.apache.hadoop.hive.ql.exec.CommonJoinOperator.internalForward(CommonJoinOperator.java:644)
at org.apache.hadoop.hive.ql.exec.CommonJoinOperator.genAllOneUniqueJoinObject(CommonJoinOperator.java:676)
at org.apache.hadoop.hive.ql.exec.CommonJoinOperator.checkAndGenObject(CommonJoinOperator.java:754)
at org.apache.hadoop.hive.ql.exec.JoinOperator.endGroup(JoinOperator.java:281)
at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.reduce(ExecReducer.java:196)
... 7 more
FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.mr.MapRedTask
此时查看表结构
desc formatted persons_orc;
可以看到SerDe Library 的格式是LazySimpleSerDe，序列化格式不是orc的,所以抛出异常
这里将表的序列化方式修改为orc即可
ALTER TABLE persons_orc SET FILEFORMAT ORC;
再看序列化格式已经是orc，使用insert(insert overwrite table persons_orc select * from persons;)插入数据可以ok
可以参考详细解释:http://www.imooc.com/article/252830
转载于:https://www.cnblogs.com/xjh713/p/10137880.html