hive Required table missing : "`DBS`" in Catalog "" Schema "
最近需要提取一些数据，故开始使用hive，本机搭建了一个hive客户端环境，但是始终有问题，在本机装好了mysql以后，老是报
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Caused by: org.datanucleus.store.rdbms.exceptions.MissingTableException: Required table missing : "`DBS`" in Catalog "" Schema "". DataNucleus requires this table to perform its persistence operations. Either your MetaData is incorrect, or you need to enable "datanucleus.autoCreateTables" at org.datanucleus.store.rdbms.table.AbstractTable.exists(AbstractTable.java:455) at org.datanucleus.store.rdbms.RDBMSStoreManager$ClassAdder.performTablesValidation(RDBMSStoreManager.java:2689) at org.datanucleus.store.rdbms.RDBMSStoreManager$ClassAdder.addClassTablesAndValidate(RDBMSStoreManager.java:2503) at org.datanucleus.store.rdbms.RDBMSStoreManager$ClassAdder.run(RDBMSStoreManager.java:2148) at org.datanucleus.store.rdbms.AbstractSchemaTransaction.execute(AbstractSchemaTransaction.java:113) at org.datanucleus.store.rdbms.RDBMSStoreManager.addClasses(RDBMSStoreManager.java:986) at org.datanucleus.store.rdbms.RDBMSStoreManager.addClasses(RDBMSStoreManager.java:952) at org.datanucleus.store.AbstractStoreManager.addClass(AbstractStoreManager.java:919) at org.datanucleus.store.mapped.MappedStoreManager.getDatastoreClass(MappedStoreManager.java:356) at org.datanucleus.store.rdbms.query.legacy.ExtentHelper.getExtent(ExtentHelper.java:48) at org.datanucleus.store.rdbms.RDBMSStoreManager.getExtent(RDBMSStoreManager.java:1332) at org.datanucleus.ObjectManagerImpl.getExtent(ObjectManagerImpl.java:4149)
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依据堆栈提示，然后下得jar文件主要是看 ?AbstractTable.exists(AbstractTable.java:455)?
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if ((type == null) || ((allowDDLOutput()) && (this.storeMgr.getDdlWriter() != null) && (this.storeMgr.getCompleteDDL()))) { if (!auto_create) { this.existsInDatastore = Boolean.FALSE; throw new MissingTableException(getCatalogName(), getSchemaName(), toString()); }?
? 455 行 便是 异常抛出之地。
?依据 hive错误提示
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?"datanucleus.autoCreateTables" = true
? 配置了hive-site.xml不行，故结合上面的代码看，猜测是autoCreate没有传递进去，故开始跟踪这个值的设置的地方，最终跟踪到org.datanucleus.store.mapped.MappedStoreManager,其中有一段很关键的代码如下
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if ((this.readOnlyDatastore) || (this.fixedDatastore)) { this.autoCreateTables = false; this.autoCreateColumns = false; this.autoCreateConstraints = false; } else { boolean autoCreateSchema = conf.getBooleanProperty("datanucleus.autoCreateSchema"); if (autoCreateSchema) { this.autoCreateTables = true; this.autoCreateColumns = true; this.autoCreateConstraints = true; } else { this.autoCreateColumns = conf.getBooleanProperty("datanucleus.autoCreateColumns"); this.autoCreateTables = conf.getBooleanProperty("datanucleus.autoCreateTables"); this.autoCreateConstraints = conf.getBooleanProperty("datanucleus.autoCreateConstraints"); } }?
? ?看来关键是?this.readOnlyDatastore ? ? ? ?this.fixedDatastore 这2个字段
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? 而且autoCreateSchema 这个设置为true 就可以决定了其他的设置，所以其他设置在此都无效了。
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? 继续追踪org.datanucleus.store.AbstractStoreManager 发现了这2个字段的设置代码
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this.readOnlyDatastore = conf.getBooleanProperty("datanucleus.readOnlyDatastore"); this.fixedDatastore = conf.getBooleanProperty("datanucleus.fixedDatastore");?? 原来问题再这里，再次修改hive-site.xml文件，ok，错误没有了。
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