我们正在使用Cloudera 5.6。我们为Hive配置了Sentry。每当我们发出一个插入语句时，它都会因以下异常而失败。但是当我们检查表格时，行正确插入。我们已将所有权限设置为hive。
$$$ insert into beckman values('rinku');
INFO : Number of reduce tasks is set to 0 since there's no reduce operator
INFO : number of splits:1
INFO : Submitting tokens for job: job_1459405260708_0002
INFO : The url to track the job: http://xxx.xxx.xxx.xxx:8088/proxy/application_1459405260708_0002/
INFO : Starting Job = job_1459405260708_0002, Tracking URL = http://xxx.xxx.xxx.xxx:8088/proxy/application_1459405260708_0002/
INFO : Kill Command = /opt/cloudera/parcels/CDH-5.6.0-1.cdh5.6.0.p0.45/lib/hadoop/bin/hadoop job -kill job_1459405260708_0002
INFO : Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
INFO : 2016-03-31 23:20:31,401 Stage-1 map = 0%, reduce = 0%
INFO : 2016-03-31 23:20:37,788 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 1.4 sec
INFO : MapReduce Total cumulative CPU time: 1 seconds 400 msec
INFO : Ended Job = job_1459405260708_0002
INFO : Stage-4 is selected by condition resolver.
INFO : Stage-3 is filtered out by condition resolver.
INFO : Stage-5 is filtered out by condition resolver.
INFO : Moving data to: hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10000 from hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10002
INFO : Loading data to table test.beckman from hdfs://ip-172-31-0-203.us-west-2.compute.internal:8020/user/hive2/warehouse/test.db/beckman/.hive-staging_hive_2016-03-31_23-20-23_107_7263355827488393299-2/-ext-10000
ERROR : Failed with exception Unable to alter table. java.lang.NullPointerException
org.apache.hadoop.hive.ql.metadata.HiveException: Unable to alter table. java.lang.NullPointerException
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:533)
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:519)
at org.apache.hadoop.hive.ql.metadata.Hive.loadTable(Hive.java:1685)
at org.apache.hadoop.hive.ql.exec.MoveTask.execute(MoveTask.java:312)
at org.apache.hadoop.hive.ql.exec.Task.executeTask(Task.java:160)
at org.apache.hadoop.hive.ql.exec.TaskRunner.runSequential(TaskRunner.java:88)
at org.apache.hadoop.hive.ql.Driver.launchTask(Driver.java:1645)
at org.apache.hadoop.hive.ql.Driver.execute(Driver.java:1404)
at org.apache.hadoop.hive.ql.Driver.runInternal(Driver.java:1190)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1055)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:1050)
at org.apache.hive.service.cli.operation.SQLOperation.runQuery(SQLOperation.java:143)
at org.apache.hive.service.cli.operation.SQLOperation.access$100(SQLOperation.java:69)
at org.apache.hive.service.cli.operation.SQLOperation$1$1.run(SQLOperation.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1707)
at org.apache.hive.service.cli.operation.SQLOperation$1.run(SQLOperation.java:207)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: MetaException(message:java.lang.NullPointerException)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result$alter_table_with_cascade_resultStandardScheme.read(ThriftHiveMetastore.java:42087)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result$alter_table_with_cascade_resultStandardScheme.read(ThriftHiveMetastore.java:42064)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$alter_table_with_cascade_result.read(ThriftHiveMetastore.java:42006)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.recv_alter_table_with_cascade(ThriftHiveMetastore.java:1402)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.alter_table_with_cascade(ThriftHiveMetastore.java:1386)
at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.alter_table(HiveMetaStoreClient.java:340)
at org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient.alter_table(SessionHiveMetaStoreClient.java:296)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.invoke(RetryingMetaStoreClient.java:91)
at com.sun.proxy.$Proxy10.alter_table(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.hive.metastore.HiveMetaStoreClient$SynchronizedHandler.invoke(HiveMetaStoreClient.java:1998)
at com.sun.proxy.$Proxy10.alter_table(Unknown Source)
at org.apache.hadoop.hive.ql.metadata.Hive.alterTable(Hive.java:531)
... 22 more
Error: Error while processing statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.MoveTask (state=08S01,code=1)
答案 0 :(得分：0)
当您尝试使用格式/语法以及数据库名称更改表时，我注意到了此问题。就像这样："<DATABASE>.<TABLENAME>" ..不知怎的，这看起来像个问题。
为了克服它，在执行实际查询之前明确提及数据库。示例说明：
use sampledb;
alter employeeTable .... ; // This works
VS
[请勿使用以下]
alter sampledb.employeeTable.... // This doesn't work