hive0.14配置參數項的功能介紹

參數項功能參照一些資料完成,留存方便查詢

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<configuration>
  <!-- WARNING!!! This file is auto generated for documentation purposes ONLY! -->
  <!-- WARNING!!! Any changes you make to this file will be ignored by Hive.   -->
  <!-- WARNING!!! You must make your changes in hive-site.xml instead.         -->
  <!-- Hive Execution Parameters -->
  <!--Script Operator 腳本調用的封裝,通常爲腳本解釋程序。例如,可以把該變量值的名稱設置爲"python",那麼傳遞到 Script Operator 的腳本將會以"python <script command>"的命令形式進行調用,如果這個值爲null或者沒有設置,那麼該腳本將會直接以"<script command>"的命令形式調用-->
  <property>
    <name>hive.exec.script.wrapper</name>
    <value/>
    <description/>
  </property>
  <!--Hive 執行計劃的路徑,會在程序中自動進行設置-->
  <property>
    <name>hive.exec.plan</name>
    <value/>
    <description/>
  </property>
  <property>
    <name>hive.plan.serialization.format</name>
    <value>kryo</value>
    <description>
      Query plan format serialization between client and task nodes. 
      Two supported values are : kryo and javaXML. Kryo is default.
    </description>
  </property>
  <!--HDFS路徑,用於存儲不同 map/reduce 階段的執行計劃和這些階段的中間輸出結果-->
  <property>
    <name>hive.exec.scratchdir</name>
    <value>/tmp/hive</value>
    <description>HDFS root scratch dir for Hive jobs which gets created with write all (733) permission. For each connecting user, an HDFS scratch dir: ${hive.exec.scratchdir}/<username> is created, with ${hive.scratch.dir.permission}.</description>
  </property>
  <property>
    <name>hive.exec.local.scratchdir</name>
    <value>${system:java.io.tmpdir}/${system:user.name}</value>
    <description>Local scratch space for Hive jobs</description>
  </property>
  <property>
    <name>hive.downloaded.resources.dir</name>
    <value>${system:java.io.tmpdir}/${hive.session.id}_resources</value>
    <description>Temporary local directory for added resources in the remote file system.</description>
  </property>
  <property>
    <name>hive.scratch.dir.permission</name>
    <value>700</value>
    <description>The permission for the user specific scratch directories that get created.</description>
  </property>
  <!--決定 map/reduce Job 是否應該使用各自獨立的 JVM 進行提交(Child進程),默認情況下,使用與 HQL compiler 相同的 JVM 進行提交-->
  <property>
    <name>hive.exec.submitviachild</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.exec.submit.local.task.via.child</name>
    <value>true</value>
    <description>
      Determines whether local tasks (typically mapjoin hashtable generation phase) runs in 
      separate JVM (true recommended) or not. 
      Avoids the overhead of spawning new JVM, but can lead to out-of-memory issues.
    </description>
  </property>
  <!--通過 TRANSFROM/MAP/REDUCE 所執行的用戶腳本所允許的最大的序列化錯誤數-->
  <property>
    <name>hive.exec.script.maxerrsize</name>
    <value>100000</value>
    <description>
      Maximum number of bytes a script is allowed to emit to standard error (per map-reduce task). 
      This prevents runaway scripts from filling logs partitions to capacity
    </description>
  </property>
  <!--是否允許腳本只處理部分數據,如果設置爲 true ,因 broken pipe 等造成的數據未處理完成將視爲正常-->
  <property>
    <name>hive.exec.script.allow.partial.consumption</name>
    <value>false</value>
    <description>
      When enabled, this option allows a user script to exit successfully without consuming 
      all the data from the standard input.
    </description>
  </property>
  <property>
    <name>stream.stderr.reporter.prefix</name>
    <value>reporter:</value>
    <description>Streaming jobs that log to standard error with this prefix can log counter or status information.</description>
  </property>
  <property>
    <name>stream.stderr.reporter.enabled</name>
    <value>true</value>
    <description>Enable consumption of status and counter messages for streaming jobs.</description>
  </property>
  <!--決定查詢中最後一個 map/reduce job 的輸出是否爲壓縮格式-->
  <property>
    <name>hive.exec.compress.output</name>
    <value>false</value>
    <description>
      This controls whether the final outputs of a query (to a local/HDFS file or a Hive table) is compressed. 
      The compression codec and other options are determined from Hadoop config variables mapred.output.compress*
    </description>
  </property>
  <!--決定查詢的中間 map/reduce job (中間 stage)的輸出是否爲壓縮格式-->
  <property>
    <name>hive.exec.compress.intermediate</name>
    <value>false</value>
    <description>
      This controls whether intermediate files produced by Hive between multiple map-reduce jobs are compressed. 
      The compression codec and other options are determined from Hadoop config variables mapred.output.compress*
    </description>
  </property>
  <!--中間 map/reduce job 的壓縮編解碼器的類名(一個壓縮編解碼器可能包含多種壓縮類型),該值可能在程序中被自動設置-->
  <property>
    <name>hive.intermediate.compression.codec</name>
    <value/>
    <description/>
  </property>
  <!--中間 map/reduce job 的壓縮類型,如 "BLOCK" "RECORD"-->
  <property>
    <name>hive.intermediate.compression.type</name>
    <value/>
    <description/>
  </property>
  <!--每一個 reducer 的平均負載字節數,默認爲256MB-->
  <property>
    <name>hive.exec.reducers.bytes.per.reducer</name>
    <value>256000000</value>
    <description>size per reducer.The default is 256Mb, i.e if the input size is 1G, it will use 4 reducers.</description>
  </property>
  <!--reducer 個數的上限.如果在規定的配置參數mapred.reduce.tasks設置的爲false,Hive將這一個值作爲reducer的上限-->
  <property>
    <name>hive.exec.reducers.max</name>
    <value>1009</value>
    <description>
      max number of reducers will be used. If the one specified in the configuration parameter mapred.reduce.tasks is
      negative, Hive will use this one as the max number of reducers when automatically determine number of reducers.
    </description>
  </property>
  <!--語句層面,整條 HQL 語句在執行前的 hook 類名-->
  <property>
    <name>hive.exec.pre.hooks</name>
    <value/>
    <description>
      Comma-separated list of pre-execution hooks to be invoked for each statement. 
      A pre-execution hook is specified as the name of a Java class which implements the 
      org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
    </description>
  </property>
  <!--語句層面,整條 HQL 語句在執行完成後的 hook 類名-->
  <property>
    <name>hive.exec.post.hooks</name>
    <value/>
    <description>
      Comma-separated list of post-execution hooks to be invoked for each statement. 
      A post-execution hook is specified as the name of a Java class which implements the 
      org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
    </description>
  </property>
  <property>
    <name>hive.exec.failure.hooks</name>
    <value/>
    <description>
      Comma-separated list of on-failure hooks to be invoked for each statement. 
      An on-failure hook is specified as the name of Java class which implements the 
      org.apache.hadoop.hive.ql.hooks.ExecuteWithHookContext interface.
    </description>
  </property>
  <property>
    <name>hive.client.stats.publishers</name>
    <value/>
    <description>
      Comma-separated list of statistics publishers to be invoked on counters on each job. 
      A client stats publisher is specified as the name of a Java class which implements the 
      org.apache.hadoop.hive.ql.stats.ClientStatsPublisher interface.
    </description>
  </property>
  <!--是否開啓 map/reduce job的併發提交-->
  <property>
    <name>hive.exec.parallel</name>
    <value>false</value>
    <description>Whether to execute jobs in parallel</description>
  </property>
  <!--併發提交時的併發線程的個數-->
  <property>
    <name>hive.exec.parallel.thread.number</name>
    <value>8</value>
    <description>How many jobs at most can be executed in parallel</description>
  </property>
  <!--是否應該把reducer下面的推測執行功能開啓-->
  <property>
    <name>hive.mapred.reduce.tasks.speculative.execution</name>
    <value>true</value>
    <description>Whether speculative execution for reducers should be turned on. </description>
  </property>
  <!--客戶端拉取 progress counters 的時間,以毫秒爲單位-->
  <property>
    <name>hive.exec.counters.pull.interval</name>
    <value>1000</value>
    <description>
      The interval with which to poll the JobTracker for the counters the running job. 
      The smaller it is the more load there will be on the jobtracker, the higher it is the less granular the caught will be.
    </description>
  </property>
  <!--在DML/DDL操作時是否打開動態分區-->
  <property>
    <name>hive.exec.dynamic.partition</name>
    <value>true</value>
    <description>Whether or not to allow dynamic partitions in DML/DDL.</description>
  </property>
  <!--打開動態分區後,動態分區的模式,有 strict 和 nonstrict 兩個值可選,strict 要求至少包含一個靜態分區列,nonstrict 則無此要求-->
  <property>
    <name>hive.exec.dynamic.partition.mode</name>
    <value>strict</value>
    <description>
      In strict mode, the user must specify at least one static partition
      in case the user accidentally overwrites all partitions.
      In nonstrict mode all partitions are allowed to be dynamic.
    </description>
  </property>
  <!--所允許的最大的動態分區的個數-->
  <property>
    <name>hive.exec.max.dynamic.partitions</name>
    <value>1000</value>
    <description>Maximum number of dynamic partitions allowed to be created in total.</description>
  </property>
  <!--單個 mapper/reducer 結點所允許的最大的動態分區的個數-->
  <property>
    <name>hive.exec.max.dynamic.partitions.pernode</name>
    <value>100</value>
    <description>Maximum number of dynamic partitions allowed to be created in each mapper/reducer node.</description>
  </property>
  <property>
    <name>hive.exec.max.created.files</name>
    <value>100000</value>
    <description>Maximum number of HDFS files created by all mappers/reducers in a MapReduce job.</description>
  </property>
  <!--默認的動態分區的名稱,當動態分區列爲''或者null時,使用此名稱-->
  <property>
    <name>hive.exec.default.partition.name</name>
    <value>__HIVE_DEFAULT_PARTITION__</value>
    <description>
      The default partition name in case the dynamic partition column value is null/empty string or any other values that cannot be escaped. 
      This value must not contain any special character used in HDFS URI (e.g., ':', '%', '/' etc). 
      The user has to be aware that the dynamic partition value should not contain this value to avoid confusions.
    </description>
  </property>
  <property>
    <name>hive.lockmgr.zookeeper.default.partition.name</name>
    <value>__HIVE_DEFAULT_ZOOKEEPER_PARTITION__</value>
    <description/>
  </property>
  <property>
    <name>hive.exec.show.job.failure.debug.info</name>
    <value>true</value>
    <description>
      If a job fails, whether to provide a link in the CLI to the task with the
      most failures, along with debugging hints if applicable.
    </description>
  </property>
  <property>
    <name>hive.exec.job.debug.capture.stacktraces</name>
    <value>true</value>
    <description>
      Whether or not stack traces parsed from the task logs of a sampled failed task 
      for each failed job should be stored in the SessionState
    </description>
  </property>
  <property>
    <name>hive.exec.job.debug.timeout</name>
    <value>30000</value>
    <description/>
  </property>
  <property>
    <name>hive.exec.tasklog.debug.timeout</name>
    <value>20000</value>
    <description/>
  </property>
  <property>
    <name>hive.output.file.extension</name>
    <value/>
    <description>
      String used as a file extension for output files. 
      If not set, defaults to the codec extension for text files (e.g. ".gz"), or no extension otherwise.
    </description>
  </property>
  <!-- 決定 Hive 是否應該自動地根據輸入文件大小,在本地運行(在GateWay運行)-->
  <property>
    <name>hive.exec.mode.local.auto</name>
    <value>true</value>
    <description>Let Hive determine whether to run in local mode automatically</description>
  </property>
  <!--如果 hive.exec.mode.local.auto 爲 true,當輸入文件大小小於此閾值時可以自動在本地模式運行,默認是 128MB-->
  <property>
    <name>hive.exec.mode.local.auto.inputbytes.max</name>
    <value>134217728</value>
    <description>When hive.exec.mode.local.auto is true, input bytes should less than this for local mode.</description>
  </property>
  <!--如果 hive.exec.mode.local.auto 爲 true,本地模式下的任務數量應該小於hive.exec.mode.local.auto.input.files.max設置的值-->
  <property>
    <name>hive.exec.mode.local.auto.input.files.max</name>
    <value>4</value>
    <description>When hive.exec.mode.local.auto is true, the number of tasks should less than this for local mode.</description>
  </property>
  <property>
    <name>hive.exec.drop.ignorenonexistent</name>
    <value>true</value>
    <description>Do not report an error if DROP TABLE/VIEW specifies a non-existent table/view</description>
  </property>
  <property>
    <name>hive.ignore.mapjoin.hint</name>
    <value>true</value>
    <description>Ignore the mapjoin hint</description>
  </property>
  <property>
    <name>hive.file.max.footer</name>
    <value>100</value>
    <description>maximum number of lines for footer user can define for a table file</description>
  </property>
  <property>
    <name>hive.resultset.use.unique.column.names</name>
    <value>true</value>
    <description>
      Make column names unique in the result set by qualifying column names with table alias if needed.
      Table alias will be added to column names for queries of type "select *" or 
      if query explicitly uses table alias "select r1.x..".
    </description>
  </property>
  <property>
    <name>fs.har.impl</name>
    <value>org.apache.hadoop.hive.shims.HiveHarFileSystem</value>
    <description>The implementation for accessing Hadoop Archives. Note that this won't be applicable to Hadoop versions less than 0.20</description>
  </property>
  <!--hive在hdfs上的默認數據存儲目錄-->
  <property>
    <name>hive.metastore.warehouse.dir</name>
    <value>/user/hive/warehouse</value>
    <description>location of default database for the warehouse</description>
  </property>
  <!--Hive 元數據的 URI,多個 thrift://地址,以英文逗號分隔-->
  <property>
    <name>hive.metastore.uris</name>
    <value/>
    <description>Thrift URI for the remote metastore. Used by metastore client to connect to remote metastore.</description>
  </property>
  <!--連接到 Thrift 元數據服務的最大重試次數-->
  <property>
    <name>hive.metastore.connect.retries</name>
    <value>3</value>
    <description>Number of retries while opening a connection to metastore</description>
  </property>
  <property>
    <name>hive.metastore.failure.retries</name>
    <value>1</value>
    <description>Number of retries upon failure of Thrift metastore calls</description>
  </property>
  <property>
    <name>hive.metastore.client.connect.retry.delay</name>
    <value>1s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Number of seconds for the client to wait between consecutive connection attempts
    </description>
  </property>
  <property>
    <name>hive.metastore.client.socket.timeout</name>
    <value>600s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      MetaStore Client socket timeout in seconds
    </description>
  </property>
  <!--元數據庫的連接密碼-->
  <property>
    <name>javax.jdo.option.ConnectionPassword</name>
    <value>mine</value>
    <description>password to use against metastore database</description>
  </property>
  <!--JDO 連接 URL Hook 的類名,該 Hook 用於獲得 JDO 元數據庫的連接字符串,爲實現了 JDOConnectionURLHook 接口的類,如果此值爲空,則使用javax.jdo.option.ConnectionURL的值-->
  <property>
    <name>hive.metastore.ds.connection.url.hook</name>
    <value/>
    <description>Name of the hook to use for retrieving the JDO connection URL. If empty, the value in javax.jdo.option.ConnectionURL is used</description>
  </property>
  <property>
    <name>javax.jdo.option.Multithreaded</name>
    <value>true</value>
    <description>Set this to true if multiple threads access metastore through JDO concurrently.</description>
  </property>
  <!--當沒有 JDO 數據連接錯誤後,嘗試連接後臺數據存儲的最大次數-->
  <property>
    <name>hive.metastore.ds.retry.attempts</name>
    <value>5</value>
  </property>
  <!--每次嘗試連接後臺數據存儲的時間間隔,以毫秒爲單位-->
  <property>
    <name>hive.metastore.ds.retry.interval</name>
    <value>1000</value>
  </property>
  <!--是否強制重新加載元數據配置,一但重新加載,該值就會被重置爲 false-->
  <property>
    <name>hive.metastore.force.reload.conf</name>
    <value>false</value>
  </property>
  <!--元數據庫的連接 URL-->
  <property>
    <name>javax.jdo.option.ConnectionURL</name>
    <value>jdbc:derby:;databaseName=metastore_db;create=true</value>
    <description>JDBC connect string for a JDBC metastore</description>
  </property>
  <property>
    <name>hive.hmshandler.retry.attempts</name>
    <value>1</value>
    <description>The number of times to retry a HMSHandler call if there were a connection error.</description>
  </property>
  <property>
    <name>hive.hmshandler.retry.interval</name>
    <value>1000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      The time between HMSHandler retry attempts on failure.
    </description>
  </property>
  <property>
    <name>hive.hmshandler.force.reload.conf</name>
    <value>false</value>
    <description>
      Whether to force reloading of the HMSHandler configuration (including
      the connection URL, before the next metastore query that accesses the
      datastore. Once reloaded, this value is reset to false. Used for
      testing only.
    </description>
  </property>
  <!--Thrift 服務線程池的最小線程數-->
  <property>
    <name>hive.metastore.server.min.threads</name>
    <value>200</value>
    <description>Minimum number of worker threads in the Thrift server's pool.</description>
  </property>
  <!--Thrift 服務線程池的最大線程數-->
  <property>
    <name>hive.metastore.server.max.threads</name>
    <value>100000</value>
    <description>Maximum number of worker threads in the Thrift server's pool.</description>
  </property>
  <!--Thrift 服務是否保持 TCP 連接-->
  <property>
    <name>hive.metastore.server.tcp.keepalive</name>
    <value>true</value>
    <description>Whether to enable TCP keepalive for the metastore server. Keepalive will prevent accumulation of half-open connections.</description>
  </property>
  <!--用於歸檔壓縮的原始中間目錄的後綴,這些目錄是什麼並不重要,只要能夠避免衝突即可-->
  <property>
    <name>hive.metastore.archive.intermediate.original</name>
    <value>_INTERMEDIATE_ORIGINAL</value>
    <description>
      Intermediate dir suffixes used for archiving. Not important what they
      are, as long as collisions are avoided
    </description>
  </property>
  <!--用於歸檔壓縮的壓縮後的中間目錄的後綴,這些目錄是什麼並不重要,只要能夠避免衝突即可-->
  <property>
    <name>hive.metastore.archive.intermediate.archived</name>
    <value>_INTERMEDIATE_ARCHIVED</value>
    <description/>
  </property>
  <!--用於歸檔壓縮的解壓後的中間目錄的後綴,這些目錄是什麼並不重要,只要能夠避免衝突即可-->
  <property>
    <name>hive.metastore.archive.intermediate.extracted</name>
    <value>_INTERMEDIATE_EXTRACTED</value>
    <description/>
  </property>
  <property>
    <name>hive.metastore.kerberos.keytab.file</name>
    <value/>
    <description>The path to the Kerberos Keytab file containing the metastore Thrift server's service principal.</description>
  </property>
  <property>
    <name>hive.metastore.kerberos.principal</name>
    <value>hive-metastore/[email protected]</value>
    <description>
      The service principal for the metastore Thrift server. 
      The special string _HOST will be replaced automatically with the correct host name.
    </description>
  </property>
  <property>
    <name>hive.metastore.sasl.enabled</name>
    <value>false</value>
    <description>If true, the metastore Thrift interface will be secured with SASL. Clients must authenticate with Kerberos.</description>
  </property>
  <property>
    <name>hive.metastore.thrift.framed.transport.enabled</name>
    <value>false</value>
    <description>If true, the metastore Thrift interface will use TFramedTransport. When false (default) a standard TTransport is used.</description>
  </property>
  <property>
    <name>hive.cluster.delegation.token.store.class</name>
    <value>org.apache.hadoop.hive.thrift.MemoryTokenStore</value>
    <description>The delegation token store implementation. Set to org.apache.hadoop.hive.thrift.ZooKeeperTokenStore for load-balanced cluster.</description>
  </property>
  <property>
    <name>hive.cluster.delegation.token.store.zookeeper.connectString</name>
    <value/>
    <description>
      The ZooKeeper token store connect string. You can re-use the configuration value
      set in hive.zookeeper.quorum, by leaving this parameter unset.
    </description>
  </property>
  <property>
    <name>hive.cluster.delegation.token.store.zookeeper.znode</name>
    <value>/hivedelegation</value>
    <description>
      The root path for token store data. Note that this is used by both HiveServer2 and
      MetaStore to store delegation Token. One directory gets created for each of them.
      The final directory names would have the servername appended to it (HIVESERVER2,
      METASTORE).
    </description>
  </property>
  <property>
    <name>hive.cluster.delegation.token.store.zookeeper.acl</name>
    <value/>
    <description>
      ACL for token store entries. Comma separated list of ACL entries. For example:
      sasl:hive/[email protected]:cdrwa,sasl:hive/[email protected]:cdrwa
      Defaults to all permissions for the hiveserver2/metastore process user.
    </description>
  </property>
  <property>
    <name>hive.metastore.cache.pinobjtypes</name>
    <value>Table,StorageDescriptor,SerDeInfo,Partition,Database,Type,FieldSchema,Order</value>
    <description>List of comma separated metastore object types that should be pinned in the cache</description>
  </property>
  <property>
    <name>datanucleus.connectionPoolingType</name>
    <value>BONECP</value>
    <description>Specify connection pool library for datanucleus</description>
  </property>
  <property>
    <name>datanucleus.validateTables</name>
    <value>false</value>
    <description>validates existing schema against code. turn this on if you want to verify existing schema</description>
  </property>
  <property>
    <name>datanucleus.validateColumns</name>
    <value>false</value>
    <description>validates existing schema against code. turn this on if you want to verify existing schema</description>
  </property>
  <property>
    <name>datanucleus.validateConstraints</name>
    <value>false</value>
    <description>validates existing schema against code. turn this on if you want to verify existing schema</description>
  </property>
  <property>
    <name>datanucleus.storeManagerType</name>
    <value>rdbms</value>
    <description>metadata store type</description>
  </property>
  <property>
    <name>datanucleus.autoCreateSchema</name>
    <value>true</value>
    <description>creates necessary schema on a startup if one doesn't exist. set this to false, after creating it once</description>
  </property>
  <property>
    <name>datanucleus.fixedDatastore</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.metastore.schema.verification</name>
    <value>false</value>
    <description>
      Enforce metastore schema version consistency.
      True: Verify that version information stored in metastore matches with one from Hive jars.  Also disable automatic
            schema migration attempt. Users are required to manually migrate schema after Hive upgrade which ensures
            proper metastore schema migration. (Default)
      False: Warn if the version information stored in metastore doesn't match with one from in Hive jars.
    </description>
  </property>
  <property>
    <name>datanucleus.autoStartMechanismMode</name>
    <value>checked</value>
    <description>throw exception if metadata tables are incorrect</description>
  </property>
  <property>
    <name>datanucleus.transactionIsolation</name>
    <value>read-committed</value>
    <description>Default transaction isolation level for identity generation.</description>
  </property>
  <property>
    <name>datanucleus.cache.level2</name>
    <value>false</value>
    <description>Use a level 2 cache. Turn this off if metadata is changed independently of Hive metastore server</description>
  </property>
  <property>
    <name>datanucleus.cache.level2.type</name>
    <value>none</value>
    <description/>
  </property>
  <property>
    <name>datanucleus.identifierFactory</name>
    <value>datanucleus1</value>
    <description>
      Name of the identifier factory to use when generating table/column names etc. 
      'datanucleus1' is used for backward compatibility with DataNucleus v1
    </description>
  </property>
  <property>
    <name>datanucleus.rdbms.useLegacyNativeValueStrategy</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>datanucleus.plugin.pluginRegistryBundleCheck</name>
    <value>LOG</value>
    <description>Defines what happens when plugin bundles are found and are duplicated [EXCEPTION|LOG|NONE]</description>
  </property>
  <property>
    <name>hive.metastore.batch.retrieve.max</name>
    <value>300</value>
    <description>
      Maximum number of objects (tables/partitions) can be retrieved from metastore in one batch. 
      The higher the number, the less the number of round trips is needed to the Hive metastore server, 
      but it may also cause higher memory requirement at the client side.
    </description>
  </property>
  <property>
    <name>hive.metastore.batch.retrieve.table.partition.max</name>
    <value>1000</value>
    <description>Maximum number of table partitions that metastore internally retrieves in one batch.</description>
  </property>
  <property>
    <name>hive.metastore.init.hooks</name>
    <value/>
    <description>
      A comma separated list of hooks to be invoked at the beginning of HMSHandler initialization. 
      An init hook is specified as the name of Java class which extends org.apache.hadoop.hive.metastore.MetaStoreInitListener.
    </description>
  </property>
  <property>
    <name>hive.metastore.pre.event.listeners</name>
    <value/>
    <description>List of comma separated listeners for metastore events.</description>
  </property>
  <property>
    <name>hive.metastore.event.listeners</name>
    <value/>
    <description/>
  </property>
  <property>
    <name>hive.metastore.authorization.storage.checks</name>
    <value>false</value>
    <description>
      Should the metastore do authorization checks against the underlying storage (usually hdfs) 
      for operations like drop-partition (disallow the drop-partition if the user in
      question doesn't have permissions to delete the corresponding directory
      on the storage).
    </description>
  </property>
  <property>
    <name>hive.metastore.event.clean.freq</name>
    <value>0s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Frequency at which timer task runs to purge expired events in metastore.
    </description>
  </property>
  <property>
    <name>hive.metastore.event.expiry.duration</name>
    <value>0s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Duration after which events expire from events table
    </description>
  </property>
  <property>
    <name>hive.metastore.execute.setugi</name>
    <value>true</value>
    <description>
      In unsecure mode, setting this property to true will cause the metastore to execute DFS operations using 
      the client's reported user and group permissions. Note that this property must be set on 
      both the client and server sides. Further note that its best effort. 
      If client sets its to true and server sets it to false, client setting will be ignored.
    </description>
  </property>
  <property>
    <name>hive.metastore.partition.name.whitelist.pattern</name>
    <value/>
    <description>Partition names will be checked against this regex pattern and rejected if not matched.</description>
  </property>
  <property>
    <name>hive.metastore.integral.jdo.pushdown</name>
    <value>false</value>
    <description>
      Allow JDO query pushdown for integral partition columns in metastore. Off by default. This
      improves metastore perf for integral columns, especially if there's a large number of partitions.
      However, it doesn't work correctly with integral values that are not normalized (e.g. have
      leading zeroes, like 0012). If metastore direct SQL is enabled and works, this optimization
      is also irrelevant.
    </description>
  </property>
  <property>
    <name>hive.metastore.try.direct.sql</name>
    <value>true</value>
    <description>
      Whether the Hive metastore should try to use direct SQL queries instead of the
      DataNucleus for certain read paths. This can improve metastore performance when
      fetching many partitions or column statistics by orders of magnitude; however, it
      is not guaranteed to work on all RDBMS-es and all versions. In case of SQL failures,
      the metastore will fall back to the DataNucleus, so it's safe even if SQL doesn't
      work for all queries on your datastore. If all SQL queries fail (for example, your
      metastore is backed by MongoDB), you might want to disable this to save the
      try-and-fall-back cost.
    </description>
  </property>
  <property>
    <name>hive.metastore.try.direct.sql.ddl</name>
    <value>true</value>
    <description>
      Same as hive.metastore.try.direct.sql, for read statements within a transaction that
      modifies metastore data. Due to non-standard behavior in Postgres, if a direct SQL
      select query has incorrect syntax or something similar inside a transaction, the
      entire transaction will fail and fall-back to DataNucleus will not be possible. You
      should disable the usage of direct SQL inside transactions if that happens in your case.
    </description>
  </property>
  <property>
    <name>hive.metastore.disallow.incompatible.col.type.changes</name>
    <value>false</value>
    <description>
      If true (default is false), ALTER TABLE operations which change the type of a
      column (say STRING) to an incompatible type (say MAP) are disallowed.
      RCFile default SerDe (ColumnarSerDe) serializes the values in such a way that the
      datatypes can be converted from string to any type. The map is also serialized as
      a string, which can be read as a string as well. However, with any binary
      serialization, this is not true. Blocking the ALTER TABLE prevents ClassCastExceptions
      when subsequently trying to access old partitions.
      
      Primitive types like INT, STRING, BIGINT, etc., are compatible with each other and are
      not blocked.
      
      See HIVE-4409 for more details.
    </description>
  </property>
  <property>
    <name>hive.table.parameters.default</name>
    <value/>
    <description>Default property values for newly created tables</description>
  </property>
  <property>
    <name>hive.ddl.createtablelike.properties.whitelist</name>
    <value/>
    <description>Table Properties to copy over when executing a Create Table Like.</description>
  </property>
  <property>
    <name>hive.metastore.rawstore.impl</name>
    <value>org.apache.hadoop.hive.metastore.ObjectStore</value>
    <description>
      Name of the class that implements org.apache.hadoop.hive.metastore.rawstore interface. 
      This class is used to store and retrieval of raw metadata objects such as table, database
    </description>
  </property>
  <property>
    <name>javax.jdo.option.ConnectionDriverName</name>
    <value>org.apache.derby.jdbc.EmbeddedDriver</value>
    <description>Driver class name for a JDBC metastore</description>
  </property>
  <property>
    <name>javax.jdo.PersistenceManagerFactoryClass</name>
    <value>org.datanucleus.api.jdo.JDOPersistenceManagerFactory</value>
    <description>class implementing the jdo persistence</description>
  </property>
  <property>
    <name>hive.metastore.expression.proxy</name>
    <value>org.apache.hadoop.hive.ql.optimizer.ppr.PartitionExpressionForMetastore</value>
    <description/>
  </property>
  <property>
    <name>javax.jdo.option.DetachAllOnCommit</name>
    <value>true</value>
    <description>Detaches all objects from session so that they can be used after transaction is committed</description>
  </property>
  <property>
    <name>javax.jdo.option.NonTransactionalRead</name>
    <value>true</value>
    <description>Reads outside of transactions</description>
  </property>
  <property>
    <name>javax.jdo.option.ConnectionUserName</name>
    <value>APP</value>
    <description>Username to use against metastore database</description>
  </property>
  <property>
    <name>hive.metastore.end.function.listeners</name>
    <value/>
    <description>List of comma separated listeners for the end of metastore functions.</description>
  </property>
  <property>
    <name>hive.metastore.partition.inherit.table.properties</name>
    <value/>
    <description>
      List of comma separated keys occurring in table properties which will get inherited to newly created partitions. 
      * implies all the keys will get inherited.
    </description>
  </property>
  <property>
    <name>hive.metadata.export.location</name>
    <value/>
    <description>
      When used in conjunction with the org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event listener, 
      it is the location to which the metadata will be exported. The default is an empty string, which results in the 
      metadata being exported to the current user's home directory on HDFS.
    </description>
  </property>
  <property>
    <name>hive.metadata.move.exported.metadata.to.trash</name>
    <value>true</value>
    <description>
      When used in conjunction with the org.apache.hadoop.hive.ql.parse.MetaDataExportListener pre event listener, 
      this setting determines if the metadata that is exported will subsequently be moved to the user's trash directory 
      alongside the dropped table data. This ensures that the metadata will be cleaned up along with the dropped table data.
    </description>
  </property>
  <!--是否忽略錯誤,對於包含多的 SQL 文件,可以忽略錯誤的行,繼續執行下一行-->
  <property>
    <name>hive.cli.errors.ignore</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.cli.print.current.db</name>
    <value>false</value>
    <description>Whether to include the current database in the Hive prompt.</description>
  </property>
  <property>
    <name>hive.cli.prompt</name>
    <value>hive</value>
    <description>
      Command line prompt configuration value. Other hiveconf can be used in this configuration value. 
      Variable substitution will only be invoked at the Hive CLI startup.
    </description>
  </property>
  <property>
    <name>hive.cli.pretty.output.num.cols</name>
    <value>-1</value>
    <description>
      The number of columns to use when formatting output generated by the DESCRIBE PRETTY table_name command.
      If the value of this property is -1, then Hive will use the auto-detected terminal width.
    </description>
  </property>
  <property>
    <name>hive.metastore.fs.handler.class</name>
    <value>org.apache.hadoop.hive.metastore.HiveMetaStoreFsImpl</value>
    <description/>
  </property>
  <!--當前會話的標識符,格式爲“用戶名_時間”用於記錄在 job conf 中,一般不予以手動設置-->
  <property>
    <name>hive.session.id</name>
    <value/>
    <description/>
  </property>
  <!--當前會話是否在 silent 模式運行。 如果不是 silent 模式,所以 info 級打在日誌中的消息,都將以標準錯誤流的形式輸出到控制檯-->
  <property>
    <name>hive.session.silent</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.session.history.enabled</name>
    <value>false</value>
    <description>Whether to log Hive query, query plan, runtime statistics etc.</description>
  </property>
  <!--當前正在被執行的查詢字符串-->
  <property>
    <name>hive.query.string</name>
    <value/>
    <description>Query being executed (might be multiple per a session)</description>
  </property>
  <!--當前正在被執行的查詢的ID-->
  <property>
    <name>hive.query.id</name>
    <value/>
    <description>ID for query being executed (might be multiple per a session)</description>
  </property>
  <!--當前正在被執行的 map/reduce plan 的 ID-->
  <property>
    <name>hive.query.planid</name>
    <value/>
  </property>
  <!--當前 job name 的最大長度,hive 會根據此長度省略 job name 的中間部分-->
  <property>
    <name>hive.jobname.length</name>
    <value>50</value>
    <description>max jobname length</description>
  </property>
  <!--通過單獨的 JVM 提交 job 時,hive_cli.jar 所在的路徑-->
  <property>
    <name>hive.jar.path</name>
    <value/>
    <description>The location of hive_cli.jar that is used when submitting jobs in a separate jvm.</description>
  </property>
  <!--各種由用戶自定義 UDF 和 SerDe 構成的插件 jar 包所在的路徑-->
  <property>
    <name>hive.aux.jars.path</name>
    <value/>
    <description>The location of the plugin jars that contain implementations of user defined functions and serdes.</description>
  </property>
  <property>
    <name>hive.reloadable.aux.jars.path</name>
    <value/>
    <description>Jars can be renewed by executing reload command. And these jars can be used as the auxiliary classes like creating a UDF or SerDe.</description>
  </property>
  <!--ADD FILE 所增加的文件的路徑-->
  <property>
    <name>hive.added.files.path</name>
    <value/>
    <description>This an internal parameter.</description>
  </property>
  <!--ADD JAR 所增加的文件的路徑-->
  <property>
    <name>hive.added.jars.path</name>
    <value/>
    <description>This an internal parameter.</description>
  </property>
  <!--ADD ARCHIEVE 所增加的文件的路徑-->
  <property>
    <name>hive.added.archives.path</name>
    <value/>
    <description>This an internal parameter.</description>
  </property>
  <property>
    <name>hive.auto.progress.timeout</name>
    <value>0s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      How long to run autoprogressor for the script/UDTF operators.
      Set to 0 for forever.
    </description>
  </property>
  <!--腳本是否週期性地向 Job Tracker 發送心跳,以避免腳本執行的時間過長,使 Job Tracker 認爲腳本已經掛掉了-->
  <property>
    <name>hive.script.auto.progress</name>
    <value>false</value>
    <description>
      Whether Hive Transform/Map/Reduce Clause should automatically send progress information to TaskTracker 
      to avoid the task getting killed because of inactivity.  Hive sends progress information when the script is 
      outputting to stderr.  This option removes the need of periodically producing stderr messages, 
      but users should be cautious because this may prevent infinite loops in the scripts to be killed by TaskTracker.
    </description>
  </property>
  <!--用於識別 ScriptOperator ID 的環境變量的名稱-->
  <property>
    <name>hive.script.operator.id.env.var</name>
    <value>HIVE_SCRIPT_OPERATOR_ID</value>
    <description>
      Name of the environment variable that holds the unique script operator ID in the user's 
      transform function (the custom mapper/reducer that the user has specified in the query)
    </description>
  </property>
  <property>
    <name>hive.script.operator.truncate.env</name>
    <value>false</value>
    <description>Truncate each environment variable for external script in scripts operator to 20KB (to fit system limits)</description>
  </property>
  <property>
    <name>hive.script.operator.env.blacklist</name>
    <value>hive.txn.valid.txns,hive.script.operator.env.blacklist</value>
    <description>Comma separated list of keys from the configuration file not to convert to environment variables when envoking the script operator</description>
  </property>
  <!--Map/Redure 模式,如果設置爲 strict,將不允許笛卡爾積-->
  <property>
    <name>hive.mapred.mode</name>
    <value>nonstrict</value>
    <description>
      The mode in which the Hive operations are being performed. 
      In strict mode, some risky queries are not allowed to run. They include:
        Cartesian Product.
        No partition being picked up for a query.
        Comparing bigints and strings.
        Comparing bigints and doubles.
        Orderby without limit.
    </description>
  </property>
  <!--當前的 Hive 別名,該配置將通過 ScriptOpertaor 傳入到用戶腳本中-->
  <property>
    <name>hive.alias</name>
    <value/>
    <description/>
  </property>
  <!--決定是否可以在 Map 端進行聚合操作-->
  <property>
    <name>hive.map.aggr</name>
    <value>true</value>
    <description>Whether to use map-side aggregation in Hive Group By queries</description>
  </property>
  <!--決定 group by 操作是否支持傾斜的數據-->
  <property>
    <name>hive.groupby.skewindata</name>
    <value>true</value>
    <description>Whether there is skew in data to optimize group by queries</description>
  </property>
  <property>
    <name>hive.optimize.multigroupby.common.distincts</name>
    <value>true</value>
    <description>
      Whether to optimize a multi-groupby query with the same distinct.
      Consider a query like:
      
        from src
          insert overwrite table dest1 select col1, count(distinct colx) group by col1
          insert overwrite table dest2 select col2, count(distinct colx) group by col2;
      
      With this parameter set to true, first we spray by the distinct value (colx), and then
      perform the 2 groups bys. This makes sense if map-side aggregation is turned off. However,
      with maps-side aggregation, it might be useful in some cases to treat the 2 inserts independently, 
      thereby performing the query above in 2MR jobs instead of 3 (due to spraying by distinct key first).
      If this parameter is turned off, we don't consider the fact that the distinct key is the same across
      different MR jobs.
    </description>
  </property>
  <!--Hive Join 操作的發射時間間隔,以毫秒爲單位-->
  <property>
    <name>hive.join.emit.interval</name>
    <value>1000</value>
    <description>How many rows in the right-most join operand Hive should buffer before emitting the join result.</description>
  </property>
  <!--Hive Join 操作的緩存大小,以字節爲單位-->
  <property>
    <name>hive.join.cache.size</name>
    <value>25000</value>
    <description>How many rows in the joining tables (except the streaming table) should be cached in memory.</description>
  </property>
  <!--基於CBO方式的執行計劃-->
  <property>
    <name>hive.cbo.enable</name>
    <value>false</value>
    <description>Flag to control enabling Cost Based Optimizations using Calcite framework.</description>
  </property>
  <!--Hive Map Join 桶的緩存大小,以字節爲單位-->
  <property>
    <name>hive.mapjoin.bucket.cache.size</name>
    <value>100</value>
    <description/>
  </property>
  <property>
    <name>hive.mapjoin.optimized.hashtable</name>
    <value>true</value>
    <description>
      Whether Hive should use memory-optimized hash table for MapJoin. Only works on Tez,
      because memory-optimized hashtable cannot be serialized.
    </description>
  </property>
  <property>
    <name>hive.mapjoin.optimized.keys</name>
    <value>true</value>
    <description>
      Whether MapJoin hashtable should use optimized (size-wise), keys, allowing the table to take less
      memory. Depending on key, the memory savings for entire table can be 5-15% or so.
    </description>
  </property>
  <property>
    <name>hive.mapjoin.lazy.hashtable</name>
    <value>true</value>
    <description>
      Whether MapJoin hashtable should deserialize values on demand. Depending on how many values in
      the table the join will actually touch, it can save a lot of memory by not creating objects for
      rows that are not needed. If all rows are needed obviously there's no gain.
    </description>
  </property>
  <property>
    <name>hive.mapjoin.optimized.hashtable.wbsize</name>
    <value>10485760</value>
    <description>
      Optimized hashtable (see hive.mapjoin.optimized.hashtable) uses a chain of buffers to
      store data. This is one buffer size. HT may be slightly faster if this is larger, but for small
      joins unnecessary memory will be allocated and then trimmed.
    </description>
  </property>
  <property>
    <name>hive.smbjoin.cache.rows</name>
    <value>10000</value>
    <description>How many rows with the same key value should be cached in memory per smb joined table.</description>
  </property>
  <!--對於 Group By 操作的 Map 聚合的檢測時間,以毫秒爲單位-->
  <property>
    <name>hive.groupby.mapaggr.checkinterval</name>
    <value>100000</value>
    <description>Number of rows after which size of the grouping keys/aggregation classes is performed</description>
  </property>
  <!--Hive Map 端聚合的哈稀存儲所佔用虛擬機的內存比例-->
  <property>
    <name>hive.map.aggr.hash.percentmemory</name>
    <value>0.5</value>
    <description>Portion of total memory to be used by map-side group aggregation hash table</description>
  </property>
  <property>
    <name>hive.mapjoin.followby.map.aggr.hash.percentmemory</name>
    <value>0.3</value>
    <description>Portion of total memory to be used by map-side group aggregation hash table, when this group by is followed by map join</description>
  </property>
  <property>
    <name>hive.map.aggr.hash.force.flush.memory.threshold</name>
    <value>0.9</value>
    <description>
      The max memory to be used by map-side group aggregation hash table.
      If the memory usage is higher than this number, force to flush data
    </description>
  </property>
  <!--Hive Map 端聚合的哈稀存儲的最小 reduce 比例-->
  <property>
    <name>hive.map.aggr.hash.min.reduction</name>
    <value>0.5</value>
    <description>
      Hash aggregation will be turned off if the ratio between hash  table size and input rows is bigger than this number. 
      Set to 1 to make sure hash aggregation is never turned off.
    </description>
  </property>
  <property>
    <name>hive.multigroupby.singlereducer</name>
    <value>true</value>
    <description>
      Whether to optimize multi group by query to generate single M/R  job plan. If the multi group by query has 
      common group by keys, it will be optimized to generate single M/R job.
    </description>
  </property>
  <property>
    <name>hive.map.groupby.sorted</name>
    <value>false</value>
    <description>
      If the bucketing/sorting properties of the table exactly match the grouping key, whether to perform 
      the group by in the mapper by using BucketizedHiveInputFormat. The only downside to this
      is that it limits the number of mappers to the number of files.
    </description>
  </property>
  <property>
    <name>hive.map.groupby.sorted.testmode</name>
    <value>false</value>
    <description>
      If the bucketing/sorting properties of the table exactly match the grouping key, whether to perform 
      the group by in the mapper by using BucketizedHiveInputFormat. If the test mode is set, the plan
      is not converted, but a query property is set to denote the same.
    </description>
  </property>
  <property>
    <name>hive.groupby.orderby.position.alias</name>
    <value>false</value>
    <description>Whether to enable using Column Position Alias in Group By or Order By</description>
  </property>
  <property>
    <name>hive.new.job.grouping.set.cardinality</name>
    <value>30</value>
    <description>
      Whether a new map-reduce job should be launched for grouping sets/rollups/cubes.
      For a query like: select a, b, c, count(1) from T group by a, b, c with rollup;
      4 rows are created per row: (a, b, c), (a, b, null), (a, null, null), (null, null, null).
      This can lead to explosion across map-reduce boundary if the cardinality of T is very high,
      and map-side aggregation does not do a very good job. 
      
      This parameter decides if Hive should add an additional map-reduce job. If the grouping set
      cardinality (4 in the example above), is more than this value, a new MR job is added under the
      assumption that the original group by will reduce the data size.
    </description>
  </property>
  <!--Hive UDTF 是否週期性地報告心跳,當 UDTF 執行時間較長且不輸出行時有用-->
  <property>
    <name>hive.udtf.auto.progress</name>
    <value>false</value>
    <description>
      Whether Hive should automatically send progress information to TaskTracker 
      when using UDTF's to prevent the task getting killed because of inactivity.  Users should be cautious 
      because this may prevent TaskTracker from killing tasks with infinite loops.
    </description>
  </property>
  <!--Hive 默認的輸出文件格式,與創建表時所指定的相同,可選項爲 'TextFile' 、 'SequenceFile' 或者 'RCFile'-->
  <property>
    <name>hive.default.fileformat</name>
    <value>TextFile</value>
    <description>
      Expects one of [textfile, sequencefile, rcfile, orc].
      Default file format for CREATE TABLE statement. Users can explicitly override it by CREATE TABLE ... STORED AS [FORMAT]
    </description>
  </property>
  <property>
    <name>hive.query.result.fileformat</name>
    <value>TextFile</value>
    <description>
      Expects one of [textfile, sequencefile, rcfile].
      Default file format for storing result of the query.
    </description>
  </property>
  <!--Hive 是否檢查輸出的文件格式-->
  <property>
    <name>hive.fileformat.check</name>
    <value>true</value>
    <description>Whether to check file format or not when loading data files</description>
  </property>
  <property>
    <name>hive.default.rcfile.serde</name>
    <value>org.apache.hadoop.hive.serde2.columnar.LazyBinaryColumnarSerDe</value>
    <description>The default SerDe Hive will use for the RCFile format</description>
  </property>
  <property>
    <name>hive.default.serde</name>
    <value>org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe</value>
    <description>The default SerDe Hive will use for storage formats that do not specify a SerDe.</description>
  </property>
  <property>
    <name>hive.serdes.using.metastore.for.schema</name>
    <value>org.apache.hadoop.hive.ql.io.orc.OrcSerde,org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe,org.apache.hadoop.hive.serde2.columnar.ColumnarSerDe,org.apache.hadoop.hive.serde2.dynamic_type.DynamicSerDe,org.apache.hadoop.hive.serde2.MetadataTypedColumnsetSerDe,org.apache.hadoop.hive.serde2.columnar.LazyBinaryColumnarSerDe,org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe,org.apache.hadoop.hive.serde2.lazybinary.LazyBinarySerDe</value>
    <description>SerDes retriving schema from metastore. This an internal parameter. Check with the hive dev. team</description>
  </property>
  <!--Hive 實時查詢日誌所在的目錄,如果該值爲空,將不創建實時的查詢日誌-->
  <property>
    <name>hive.querylog.location</name>
    <value>${system:java.io.tmpdir}/${system:user.name}</value>
    <description>Location of Hive run time structured log file</description>
  </property>
  <property>
    <name>hive.querylog.enable.plan.progress</name>
    <value>true</value>
    <description>
      Whether to log the plan's progress every time a job's progress is checked.
      These logs are written to the location specified by hive.querylog.location
    </description>
  </property>
  <property>
    <name>hive.querylog.plan.progress.interval</name>
    <value>60000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      The interval to wait between logging the plan's progress.
      If there is a whole number percentage change in the progress of the mappers or the reducers,
      the progress is logged regardless of this value.
      The actual interval will be the ceiling of (this value divided by the value of
      hive.exec.counters.pull.interval) multiplied by the value of hive.exec.counters.pull.interval
      I.e. if it is not divide evenly by the value of hive.exec.counters.pull.interval it will be
      logged less frequently than specified.
      This only has an effect if hive.querylog.enable.plan.progress is set to true.
    </description>
  </property>
  <!--Hive 用戶腳本的 SerDe-->
  <property>
    <name>hive.script.serde</name>
    <value>org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe</value>
    <description>The default SerDe for transmitting input data to and reading output data from the user scripts. </description>
  </property>
  <!--Hive 用戶腳本的 RecordRedaer-->
  <property>
    <name>hive.script.recordreader</name>
    <value>org.apache.hadoop.hive.ql.exec.TextRecordReader</value>
    <description>The default record reader for reading data from the user scripts. </description>
  </property>
  <!--Hive 用戶腳本的 RecordWriter-->
  <property>
    <name>hive.script.recordwriter</name>
    <value>org.apache.hadoop.hive.ql.exec.TextRecordWriter</value>
    <description>The default record writer for writing data to the user scripts. </description>
  </property>
  <property>
    <name>hive.transform.escape.input</name>
    <value>false</value>
    <description>
      This adds an option to escape special chars (newlines, carriage returns and
      tabs) when they are passed to the user script. This is useful if the Hive tables
      can contain data that contains special characters.
    </description>
  </property>
  <property>
    <name>hive.binary.record.max.length</name>
    <value>1000</value>
    <description>
      Read from a binary stream and treat each hive.binary.record.max.length bytes as a record. 
      The last record before the end of stream can have less than hive.binary.record.max.length bytes
    </description>
  </property>
  <!--HWI 所綁定的 HOST 或者 IP-->
  <property>
    <name>hive.hwi.listen.host</name>
    <value>0.0.0.0</value>
    <description>This is the host address the Hive Web Interface will listen on</description>
  </property>
  <!--HWI 所監聽的 HTTP 端口-->
  <property>
    <name>hive.hwi.listen.port</name>
    <value>9999</value>
    <description>This is the port the Hive Web Interface will listen on</description>
  </property>
  <!--HWI 的 war 文件所在的路徑-->
  <property>
    <name>hive.hwi.war.file</name>
    <value>${env:HWI_WAR_FILE}</value>
    <description>This sets the path to the HWI war file, relative to ${HIVE_HOME}. </description>
  </property>
  <!--Mapper/Reducer 在本地模式的最大內存量,以字節爲單位,0爲不限制-->
  <property>
    <name>hive.mapred.local.mem</name>
    <value>0</value>
    <description>mapper/reducer memory in local mode</description>
  </property>
  <property>
    <name>hive.mapjoin.smalltable.filesize</name>
    <value>25000000</value>
    <description>
      The threshold for the input file size of the small tables; if the file size is smaller 
      than this threshold, it will try to convert the common join into map join
    </description>
  </property>
  <property>
    <name>hive.sample.seednumber</name>
    <value>0</value>
    <description>A number used to percentage sampling. By changing this number, user will change the subsets of data sampled.</description>
  </property>
  <!--是否以測試模式運行 Hive-->
  <property>
    <name>hive.test.mode</name>
    <value>false</value>
    <description>Whether Hive is running in test mode. If yes, it turns on sampling and prefixes the output tablename.</description>
  </property>
  <!--Hive 測試模式的前綴-->
  <property>
    <name>hive.test.mode.prefix</name>
    <value>test_</value>
    <description>In test mode, specfies prefixes for the output table</description>
  </property>
  <!--Hive 測試模式取樣的頻率,即每秒鐘取樣的次數-->
  <property>
    <name>hive.test.mode.samplefreq</name>
    <value>32</value>
    <description>
      In test mode, specfies sampling frequency for table, which is not bucketed,
      For example, the following query:
        INSERT OVERWRITE TABLE dest SELECT col1 from src
      would be converted to
        INSERT OVERWRITE TABLE test_dest
        SELECT col1 from src TABLESAMPLE (BUCKET 1 out of 32 on rand(1))
    </description>
  </property>
  <!--Hive 測試模式取樣的排除列表,以逗號分隔-->
  <property>
    <name>hive.test.mode.nosamplelist</name>
    <value/>
    <description>In test mode, specifies comma separated table names which would not apply sampling</description>
  </property>
  <property>
    <name>hive.test.dummystats.aggregator</name>
    <value/>
    <description>internal variable for test</description>
  </property>
  <property>
    <name>hive.test.dummystats.publisher</name>
    <value/>
    <description>internal variable for test</description>
  </property>
  <!--是否開啓合併 Map 端小文件,對於 Hadoop 0.20 以前的版本,起一個新的 Map/Reduce Job,對於 0.20 以後的版本,則是起使用 CombineInputFormat 的 MapOnly Job-->
  <property>
    <name>hive.merge.mapfiles</name>
    <value>true</value>
    <description>Merge small files at the end of a map-only job</description>
  </property>
  <!--是否開啓合併 Reduce端生成的小文件-->
  <property>
    <name>hive.merge.mapredfiles</name>
    <value>true</value>
    <description>Merge small files at the end of a map-reduce job</description>
  </property>
  <property>
    <name>hive.merge.tezfiles</name>
    <value>false</value>
    <description>Merge small files at the end of a Tez DAG</description>
  </property>
  <!--每個任務合併後文件的大小,根據此大小確定 reducer 的個數,默認 256 M-->
  <property>
    <name>hive.merge.size.per.task</name>
    <value>256000000</value>
    <description>Size of merged files at the end of the job</description>
  </property>
  <!--需要合併的小文件羣的平均大小,默認 16 M-->
  <property>
    <name>hive.merge.smallfiles.avgsize</name>
    <value>16000000</value>
    <description>
      When the average output file size of a job is less than this number, Hive will start an additional 
      map-reduce job to merge the output files into bigger files. This is only done for map-only jobs 
      if hive.merge.mapfiles is true, and for map-reduce jobs if hive.merge.mapredfiles is true.
    </description>
  </property>
  <property>
    <name>hive.merge.rcfile.block.level</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>hive.merge.orcfile.stripe.level</name>
    <value>true</value>
    <description>
      When hive.merge.mapfiles, hive.merge.mapredfiles or hive.merge.tezfiles is enabled
      while writing a table with ORC file format, enabling this config will do stripe-level
      fast merge for small ORC files. Note that enabling this config will not honor the
      padding tolerance config (hive.exec.orc.block.padding.tolerance).
    </description>
  </property>
  <property>
    <name>hive.exec.rcfile.use.explicit.header</name>
    <value>true</value>
    <description>
      If this is set the header for RCFiles will simply be RCF.  If this is not
      set the header will be that borrowed from sequence files, e.g. SEQ- followed
      by the input and output RCFile formats.
    </description>
  </property>
  <property>
    <name>hive.exec.rcfile.use.sync.cache</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>hive.io.rcfile.record.interval</name>
    <value>2147483647</value>
    <description/>
  </property>
  <property>
    <name>hive.io.rcfile.column.number.conf</name>
    <value>0</value>
    <description/>
  </property>
  <property>
    <name>hive.io.rcfile.tolerate.corruptions</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.io.rcfile.record.buffer.size</name>
    <value>4194304</value>
    <description/>
  </property>
  <property>
    <name>hive.exec.orc.memory.pool</name>
    <value>0.5</value>
    <description>Maximum fraction of heap that can be used by ORC file writers</description>
  </property>
  <property>
    <name>hive.exec.orc.write.format</name>
    <value/>
    <description>
      Define the version of the file to write. Possible values are 0.11 and 0.12.
      If this parameter is not defined, ORC will use the run length encoding (RLE)
      introduced in Hive 0.12. Any value other than 0.11 results in the 0.12 encoding.
    </description>
  </property>
  <property>
    <name>hive.exec.orc.default.stripe.size</name>
    <value>67108864</value>
    <description>Define the default ORC stripe size, in bytes.</description>
  </property>
  <property>
    <name>hive.exec.orc.default.block.size</name>
    <value>268435456</value>
    <description>Define the default file system block size for ORC files.</description>
  </property>
  <property>
    <name>hive.exec.orc.dictionary.key.size.threshold</name>
    <value>0.8</value>
    <description>
      If the number of keys in a dictionary is greater than this fraction of the total number of
      non-null rows, turn off dictionary encoding.  Use 1 to always use dictionary encoding.
    </description>
  </property>
  <property>
    <name>hive.exec.orc.default.row.index.stride</name>
    <value>10000</value>
    <description>
      Define the default ORC index stride in number of rows. (Stride is the number of rows
      an index entry represents.)
    </description>
  </property>
  <property>
    <name>hive.orc.row.index.stride.dictionary.check</name>
    <value>true</value>
    <description>
      If enabled dictionary check will happen after first row index stride (default 10000 rows)
      else dictionary check will happen before writing first stripe. In both cases, the decision
      to use dictionary or not will be retained thereafter.
    </description>
  </property>
  <property>
    <name>hive.exec.orc.default.buffer.size</name>
    <value>262144</value>
    <description>Define the default ORC buffer size, in bytes.</description>
  </property>
  <property>
    <name>hive.exec.orc.default.block.padding</name>
    <value>true</value>
    <description>Define the default block padding, which pads stripes to the HDFS block boundaries.</description>
  </property>
  <property>
    <name>hive.exec.orc.block.padding.tolerance</name>
    <value>0.05</value>
    <description>
      Define the tolerance for block padding as a decimal fraction of stripe size (for
      example, the default value 0.05 is 5% of the stripe size). For the defaults of 64Mb
      ORC stripe and 256Mb HDFS blocks, the default block padding tolerance of 5% will
      reserve a maximum of 3.2Mb for padding within the 256Mb block. In that case, if the
      available size within the block is more than 3.2Mb, a new smaller stripe will be
      inserted to fit within that space. This will make sure that no stripe written will
      cross block boundaries and cause remote reads within a node local task.
    </description>
  </property>
  <property>
    <name>hive.exec.orc.default.compress</name>
    <value>ZLIB</value>
    <description>Define the default compression codec for ORC file</description>
  </property>
  <property>
    <name>hive.exec.orc.encoding.strategy</name>
    <value>SPEED</value>
    <description>
      Expects one of [speed, compression].
      Define the encoding strategy to use while writing data. Changing this will
      only affect the light weight encoding for integers. This flag will not
      change the compression level of higher level compression codec (like ZLIB).
    </description>
  </property>
  <property>
    <name>hive.exec.orc.compression.strategy</name>
    <value>SPEED</value>
    <description>
      Expects one of [speed, compression].
      Define the compression strategy to use while writing data. 
      This changes the compression level of higher level compression codec (like ZLIB).
    </description>
  </property>
  <property>
    <name>hive.orc.splits.include.file.footer</name>
    <value>false</value>
    <description>
      If turned on splits generated by orc will include metadata about the stripes in the file. This
      data is read remotely (from the client or HS2 machine) and sent to all the tasks.
    </description>
  </property>
  <property>
    <name>hive.orc.cache.stripe.details.size</name>
    <value>10000</value>
    <description>Cache size for keeping meta info about orc splits cached in the client.</description>
  </property>
  <property>
    <name>hive.orc.compute.splits.num.threads</name>
    <value>10</value>
    <description>How many threads orc should use to create splits in parallel.</description>
  </property>
  <property>
    <name>hive.exec.orc.skip.corrupt.data</name>
    <value>false</value>
    <description>
      If ORC reader encounters corrupt data, this value will be used to determine
      whether to skip the corrupt data or throw exception. The default behavior is to throw exception.
    </description>
  </property>
  <property>
    <name>hive.exec.orc.zerocopy</name>
    <value>false</value>
    <description>Use zerocopy reads with ORC. (This requires Hadoop 2.3 or later.)</description>
  </property>
  <property>
    <name>hive.lazysimple.extended_boolean_literal</name>
    <value>false</value>
    <description>
      LazySimpleSerde uses this property to determine if it treats 'T', 't', 'F', 'f',
      '1', and '0' as extened, legal boolean literal, in addition to 'TRUE' and 'FALSE'.
      The default is false, which means only 'TRUE' and 'FALSE' are treated as legal
      boolean literal.
    </description>
  </property>
  <!--是否優化數據傾斜的 Join,對於傾斜的 Join 會開啓新的 Map/Reduce Job 處理-->
  <property>
    <name>hive.optimize.skewjoin</name>
    <value>false</value>
    <description>
      Whether to enable skew join optimization. 
      The algorithm is as follows: At runtime, detect the keys with a large skew. Instead of
      processing those keys, store them temporarily in an HDFS directory. In a follow-up map-reduce
      job, process those skewed keys. The same key need not be skewed for all the tables, and so,
      the follow-up map-reduce job (for the skewed keys) would be much faster, since it would be a
      map-join.
    </description>
  </property>
  <!--是否根據輸入小表的大小,自動將 Reduce 端的 Common Join 轉化爲 Map Join,從而加快大表關聯小表的 Join 速度-->
  <property>
    <name>hive.auto.convert.join</name>
    <value>true</value>
    <description>Whether Hive enables the optimization about converting common join into mapjoin based on the input file size</description>
  </property>
  <property>
    <name>hive.auto.convert.join.noconditionaltask</name>
    <value>true</value>
    <description>
      Whether Hive enables the optimization about converting common join into mapjoin based on the input file size. 
      If this parameter is on, and the sum of size for n-1 of the tables/partitions for a n-way join is smaller than the
      specified size, the join is directly converted to a mapjoin (there is no conditional task).
    </description>
  </property>
  <property>
    <name>hive.auto.convert.join.noconditionaltask.size</name>
    <value>10000000</value>
    <description>
      If hive.auto.convert.join.noconditionaltask is off, this parameter does not take affect. 
      However, if it is on, and the sum of size for n-1 of the tables/partitions for a n-way join is smaller than this size, 
      the join is directly converted to a mapjoin(there is no conditional task). The default is 10MB
    </description>
  </property>
  <property>
    <name>hive.auto.convert.join.use.nonstaged</name>
    <value>false</value>
    <description>
      For conditional joins, if input stream from a small alias can be directly applied to join operator without 
      filtering or projection, the alias need not to be pre-staged in distributed cache via mapred local task.
      Currently, this is not working with vectorization or tez execution engine.
    </description>
  </property>
  <!--傾斜鍵數目閾值,超過此值則判定爲一個傾斜的 Join 查詢-->
  <property>
    <name>hive.skewjoin.key</name>
    <value>100000</value>
    <description>
      Determine if we get a skew key in join. If we see more than the specified number of rows with the same key in join operator,
      we think the key as a skew join key. 
    </description>
  </property>
  <!--處理數據傾斜的 Map Join 的 Map 數上限-->
  <property>
    <name>hive.skewjoin.mapjoin.map.tasks</name>
    <value>10000</value>
    <description>
      Determine the number of map task used in the follow up map join job for a skew join.
      It should be used together with hive.skewjoin.mapjoin.min.split to perform a fine grained control.
    </description>
  </property>
  <!--處理數據傾斜的 Map Join 的最小數據切分大小,以字節爲單位,默認爲32M-->
  <property>
    <name>hive.skewjoin.mapjoin.min.split</name>
    <value>33554432</value>
    <description>
      Determine the number of map task at most used in the follow up map join job for a skew join by specifying 
      the minimum split size. It should be used together with hive.skewjoin.mapjoin.map.tasks to perform a fine grained control.
    </description>
  </property>
  <!--Hive Job 的心跳間隔,以毫秒爲單位-->
  <property>
    <name>hive.heartbeat.interval</name>
    <value>1000</value>
    <description>Send a heartbeat after this interval - used by mapjoin and filter operators</description>
  </property>
  <property>
    <name>hive.limit.row.max.size</name>
    <value>100000</value>
    <description>When trying a smaller subset of data for simple LIMIT, how much size we need to guarantee each row to have at least.</description>
  </property>
  <property>
    <name>hive.limit.optimize.limit.file</name>
    <value>10</value>
    <description>When trying a smaller subset of data for simple LIMIT, maximum number of files we can sample.</description>
  </property>
  <property>
    <name>hive.limit.optimize.enable</name>
    <value>false</value>
    <description>Whether to enable to optimization to trying a smaller subset of data for simple LIMIT first.</description>
  </property>
  <property>
    <name>hive.limit.optimize.fetch.max</name>
    <value>50000</value>
    <description>
      Maximum number of rows allowed for a smaller subset of data for simple LIMIT, if it is a fetch query. 
      Insert queries are not restricted by this limit.
    </description>
  </property>
  <property>
    <name>hive.limit.pushdown.memory.usage</name>
    <value>-1.0</value>
    <description>The max memory to be used for hash in RS operator for top K selection.</description>
  </property>
  <property>
    <name>hive.limit.query.max.table.partition</name>
    <value>-1</value>
    <description>
      This controls how many partitions can be scanned for each partitioned table.
      The default value "-1" means no limit.
    </description>
  </property>
  <property>
    <name>hive.hashtable.key.count.adjustment</name>
    <value>1.0</value>
    <description>Adjustment to mapjoin hashtable size derived from table and column statistics; the estimate of the number of keys is divided by this value. If the value is 0, statistics are not usedand hive.hashtable.initialCapacity is used instead.</description>
  </property>
  <!--Hive 的 Map Join 會將小表 dump 到一個內存的 HashTable 中,該 HashTable 的初始大小由此參數指定-->
  <property>
    <name>hive.hashtable.initialCapacity</name>
    <value>100000</value>
    <description>Initial capacity of mapjoin hashtable if statistics are absent, or if hive.hashtable.stats.key.estimate.adjustment is set to 0</description>
  </property>
  <!--Hive 的 Map Join 會將小表 dump 到一個內存的 HashTable 中,該 HashTable 的負載因子由此參數指定-->
  <property>
    <name>hive.hashtable.loadfactor</name>
    <value>0.75</value>
    <description/>
  </property>
  <!--MapJoinOperator後面跟隨GroupByOperator時,內存的最大使用比例-->
  <property>
    <name>hive.mapjoin.followby.gby.localtask.max.memory.usage</name>
    <value>0.55</value>
    <description>
      This number means how much memory the local task can take to hold the key/value into an in-memory hash table 
      when this map join is followed by a group by. If the local task's memory usage is more than this number, 
      the local task will abort by itself. It means the data of the small table is too large to be held in memory.
    </description>
  </property>
  <!--Map Join 的本地任務使用堆內存的最大比例-->
  <property>
    <name>hive.mapjoin.localtask.max.memory.usage</name>
    <value>0.9</value>
    <description>
      This number means how much memory the local task can take to hold the key/value into an in-memory hash table. 
      If the local task's memory usage is more than this number, the local task will abort by itself. 
      It means the data of the small table is too large to be held in memory.
    </description>
  </property>
  <!--設置每多少行檢測一次內存的大小,如果超過 hive.mapjoin.localtask.max.memory.usage 則會異常退出,Map Join 失敗-->
  <property>
    <name>hive.mapjoin.check.memory.rows</name>
    <value>100000</value>
    <description>The number means after how many rows processed it needs to check the memory usage</description>
  </property>
  <!--是否調試本地任務,目前該參數沒有生效-->
  <property>
    <name>hive.debug.localtask</name>
    <value>false</value>
    <description/>
  </property>
  <!--Hive 的輸入 InputFormat。  默認是org.apache.hadoop.hive.ql.io.HiveInputFormat,其他還有org.apache.hadoop.hive.ql.io.CombineHiveInputFormat-->
  <property>
    <name>hive.input.format</name>
    <value>org.apache.hadoop.hive.ql.io.CombineHiveInputFormat</value>
    <description>The default input format. Set this to HiveInputFormat if you encounter problems with CombineHiveInputFormat.</description>
  </property>
  <property>
    <name>hive.tez.input.format</name>
    <value>org.apache.hadoop.hive.ql.io.HiveInputFormat</value>
    <description>The default input format for tez. Tez groups splits in the AM.</description>
  </property>
  <property>
    <name>hive.tez.container.size</name>
    <value>-1</value>
    <description>By default Tez will spawn containers of the size of a mapper. This can be used to overwrite.</description>
  </property>
  <property>
    <name>hive.tez.cpu.vcores</name>
    <value>-1</value>
    <description>
      By default Tez will ask for however many cpus map-reduce is configured to use per container.
      This can be used to overwrite.
    </description>
  </property>
  <property>
    <name>hive.tez.java.opts</name>
    <value/>
    <description>By default Tez will use the Java options from map tasks. This can be used to overwrite.</description>
  </property>
  <property>
    <name>hive.tez.log.level</name>
    <value>INFO</value>
    <description>
      The log level to use for tasks executing as part of the DAG.
      Used only if hive.tez.java.opts is used to configure Java options.
    </description>
  </property>
  <!--是否啓用強制 bucketing-->
  <property>
    <name>hive.enforce.bucketing</name>
    <value>false</value>
    <description>Whether bucketing is enforced. If true, while inserting into the table, bucketing is enforced.</description>
  </property>
  <!--是否啓用強制排序-->
  <property>
    <name>hive.enforce.sorting</name>
    <value>false</value>
    <description>Whether sorting is enforced. If true, while inserting into the table, sorting is enforced.</description>
  </property>
  <property>
    <name>hive.optimize.bucketingsorting</name>
    <value>true</value>
    <description>
      If hive.enforce.bucketing or hive.enforce.sorting is true, don't create a reducer for enforcing 
      bucketing/sorting for queries of the form: 
      insert overwrite table T2 select * from T1;
      where T1 and T2 are bucketed/sorted by the same keys into the same number of buckets.
    </description>
  </property>
  <!--Hive 的 Partitioner 類-->
  <property>
    <name>hive.mapred.partitioner</name>
    <value>org.apache.hadoop.hive.ql.io.DefaultHivePartitioner</value>
    <description/>
  </property>
  <property>
    <name>hive.enforce.sortmergebucketmapjoin</name>
    <value>false</value>
    <description>If the user asked for sort-merge bucketed map-side join, and it cannot be performed, should the query fail or not ?</description>
  </property>
  <property>
    <name>hive.enforce.bucketmapjoin</name>
    <value>false</value>
    <description>
      If the user asked for bucketed map-side join, and it cannot be performed, 
      should the query fail or not ? For example, if the buckets in the tables being joined are
      not a multiple of each other, bucketed map-side join cannot be performed, and the
      query will fail if hive.enforce.bucketmapjoin is set to true.
    </description>
  </property>
  <property>
    <name>hive.auto.convert.sortmerge.join</name>
    <value>false</value>
    <description>Will the join be automatically converted to a sort-merge join, if the joined tables pass the criteria for sort-merge join.</description>
  </property>
  <property>
    <name>hive.auto.convert.sortmerge.join.bigtable.selection.policy</name>
    <value>org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ</value>
    <description>
      The policy to choose the big table for automatic conversion to sort-merge join. 
      By default, the table with the largest partitions is assigned the big table. All policies are:
      . based on position of the table - the leftmost table is selected
      org.apache.hadoop.hive.ql.optimizer.LeftmostBigTableSMJ.
      . based on total size (all the partitions selected in the query) of the table 
      org.apache.hadoop.hive.ql.optimizer.TableSizeBasedBigTableSelectorForAutoSMJ.
      . based on average size (all the partitions selected in the query) of the table 
      org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ.
      New policies can be added in future.
    </description>
  </property>
  <property>
    <name>hive.auto.convert.sortmerge.join.to.mapjoin</name>
    <value>false</value>
    <description>
      If hive.auto.convert.sortmerge.join is set to true, and a join was converted to a sort-merge join, 
      this parameter decides whether each table should be tried as a big table, and effectively a map-join should be
      tried. That would create a conditional task with n+1 children for a n-way join (1 child for each table as the
      big table), and the backup task will be the sort-merge join. In some cases, a map-join would be faster than a
      sort-merge join, if there is no advantage of having the output bucketed and sorted. For example, if a very big sorted
      and bucketed table with few files (say 10 files) are being joined with a very small sorter and bucketed table
      with few files (10 files), the sort-merge join will only use 10 mappers, and a simple map-only join might be faster
      if the complete small table can fit in memory, and a map-join can be performed.
    </description>
  </property>
  <!--Hive Script Operator For trust-->
  <property>
    <name>hive.exec.script.trust</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.exec.rowoffset</name>
    <value>false</value>
    <description>Whether to provide the row offset virtual column</description>
  </property>
  <!--是否支持可切分的 CombieInputFormat-->
  <property>
    <name>hive.hadoop.supports.splittable.combineinputformat</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.optimize.index.filter</name>
    <value>false</value>
    <description>Whether to enable automatic use of indexes</description>
  </property>
  <property>
    <name>hive.optimize.index.autoupdate</name>
    <value>false</value>
    <description>Whether to update stale indexes automatically</description>
  </property>
  <!--是否優化謂詞下推-->
  <property>
    <name>hive.optimize.ppd</name>
    <value>true</value>
    <description>Whether to enable predicate pushdown</description>
  </property>
  <property>
    <name>hive.ppd.recognizetransivity</name>
    <value>true</value>
    <description>Whether to transitively replicate predicate filters over equijoin conditions.</description>
  </property>
  <property>
    <name>hive.ppd.remove.duplicatefilters</name>
    <value>true</value>
    <description>Whether to push predicates down into storage handlers.  Ignored when hive.optimize.ppd is false.</description>
  </property>
  <property>
    <name>hive.optimize.constant.propagation</name>
    <value>true</value>
    <description>Whether to enable constant propagation optimizer</description>
  </property>
  <property>
    <name>hive.optimize.metadataonly</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>hive.optimize.null.scan</name>
    <value>true</value>
    <description>Dont scan relations which are guaranteed to not generate any rows</description>
  </property>
  <property>
    <name>hive.optimize.ppd.storage</name>
    <value>true</value>
    <description>Whether to push predicates down to storage handlers</description>
  </property>
  <!--是否優化 group by-->
  <property>
    <name>hive.optimize.groupby</name>
    <value>true</value>
    <description>Whether to enable the bucketed group by from bucketed partitions/tables.</description>
  </property>
  <!--是否優化 bucket map join-->
  <property>
    <name>hive.optimize.bucketmapjoin</name>
    <value>false</value>
    <description>Whether to try bucket mapjoin</description>
  </property>
  <!--是否在優化 bucket map join 時嘗試使用強制 sorted merge bucket map join-->
  <property>
    <name>hive.optimize.bucketmapjoin.sortedmerge</name>
    <value>false</value>
    <description>Whether to try sorted bucket merge map join</description>
  </property>
  <!--是否優化 reduce 冗餘-->
  <property>
    <name>hive.optimize.reducededuplication</name>
    <value>true</value>
    <description>
      Remove extra map-reduce jobs if the data is already clustered by the same key which needs to be used again. 
      This should always be set to true. Since it is a new feature, it has been made configurable.
    </description>
  </property>
  <property>
    <name>hive.optimize.reducededuplication.min.reducer</name>
    <value>4</value>
    <description>
      Reduce deduplication merges two RSs by moving key/parts/reducer-num of the child RS to parent RS. 
      That means if reducer-num of the child RS is fixed (order by or forced bucketing) and small, it can make very slow, single MR.
      The optimization will be automatically disabled if number of reducers would be less than specified value.
    </description>
  </property>
  <property>
    <name>hive.optimize.sort.dynamic.partition</name>
    <value>false</value>
    <description>
      When enabled dynamic partitioning column will be globally sorted.
      This way we can keep only one record writer open for each partition value
      in the reducer thereby reducing the memory pressure on reducers.
    </description>
  </property>
  <property>
    <name>hive.optimize.sampling.orderby</name>
    <value>false</value>
    <description>Uses sampling on order-by clause for parallel execution.</description>
  </property>
  <property>
    <name>hive.optimize.sampling.orderby.number</name>
    <value>1000</value>
    <description>Total number of samples to be obtained.</description>
  </property>
  <property>
    <name>hive.optimize.sampling.orderby.percent</name>
    <value>0.1</value>
    <description>
      Expects value between 0.0f and 1.0f.
      Probability with which a row will be chosen.
    </description>
  </property>
  <property>
    <name>hive.optimize.union.remove</name>
    <value>false</value>
    <description>
      Whether to remove the union and push the operators between union and the filesink above union. 
      This avoids an extra scan of the output by union. This is independently useful for union
      queries, and specially useful when hive.optimize.skewjoin.compiletime is set to true, since an
      extra union is inserted.
      
      The merge is triggered if either of hive.merge.mapfiles or hive.merge.mapredfiles is set to true.
      If the user has set hive.merge.mapfiles to true and hive.merge.mapredfiles to false, the idea was the
      number of reducers are few, so the number of files anyway are small. However, with this optimization,
      we are increasing the number of files possibly by a big margin. So, we merge aggressively.
    </description>
  </property>
  <property>
    <name>hive.optimize.correlation</name>
    <value>false</value>
    <description>exploit intra-query correlations.</description>
  </property>
  <property>
    <name>hive.mapred.supports.subdirectories</name>
    <value>false</value>
    <description>
      Whether the version of Hadoop which is running supports sub-directories for tables/partitions. 
      Many Hive optimizations can be applied if the Hadoop version supports sub-directories for
      tables/partitions. It was added by MAPREDUCE-1501
    </description>
  </property>
  <property>
    <name>hive.optimize.skewjoin.compiletime</name>
    <value>false</value>
    <description>
      Whether to create a separate plan for skewed keys for the tables in the join.
      This is based on the skewed keys stored in the metadata. At compile time, the plan is broken
      into different joins: one for the skewed keys, and the other for the remaining keys. And then,
      a union is performed for the 2 joins generated above. So unless the same skewed key is present
      in both the joined tables, the join for the skewed key will be performed as a map-side join.
      
      The main difference between this parameter and hive.optimize.skewjoin is that this parameter
      uses the skew information stored in the metastore to optimize the plan at compile time itself.
      If there is no skew information in the metadata, this parameter will not have any affect.
      Both hive.optimize.skewjoin.compiletime and hive.optimize.skewjoin should be set to true.
      Ideally, hive.optimize.skewjoin should be renamed as hive.optimize.skewjoin.runtime, but not doing
      so for backward compatibility.
      
      If the skew information is correctly stored in the metadata, hive.optimize.skewjoin.compiletime
      would change the query plan to take care of it, and hive.optimize.skewjoin will be a no-op.
    </description>
  </property>
  <property>
    <name>hive.optimize.index.filter.compact.minsize</name>
    <value>5368709120</value>
    <description>Minimum size (in bytes) of the inputs on which a compact index is automatically used.</description>
  </property>
  <property>
    <name>hive.optimize.index.filter.compact.maxsize</name>
    <value>-1</value>
    <description>Maximum size (in bytes) of the inputs on which a compact index is automatically used.  A negative number is equivalent to infinity.</description>
  </property>
  <property>
    <name>hive.index.compact.query.max.entries</name>
    <value>10000000</value>
    <description>The maximum number of index entries to read during a query that uses the compact index. Negative value is equivalent to infinity.</description>
  </property>
  <property>
    <name>hive.index.compact.query.max.size</name>
    <value>10737418240</value>
    <description>The maximum number of bytes that a query using the compact index can read. Negative value is equivalent to infinity.</description>
  </property>
  <property>
    <name>hive.index.compact.binary.search</name>
    <value>true</value>
    <description>Whether or not to use a binary search to find the entries in an index table that match the filter, where possible</description>
  </property>
  <property>
    <name>hive.stats.autogather</name>
    <value>true</value>
    <description>A flag to gather statistics automatically during the INSERT OVERWRITE command.</description>
  </property>
  <property>
    <name>hive.stats.dbclass</name>
    <value>fs</value>
    <description>
      Expects one of the pattern in [jdbc(:.*), hbase, counter, custom, fs].
      The storage that stores temporary Hive statistics. In filesystem based statistics collection ('fs'), 
      each task writes statistics it has collected in a file on the filesystem, which will be aggregated 
      after the job has finished. Supported values are fs (filesystem), jdbc:database (where database 
      can be derby, mysql, etc.), hbase, counter, and custom as defined in StatsSetupConst.java.
    </description>
  </property>
  <property>
    <name>hive.stats.jdbcdriver</name>
    <value>org.apache.derby.jdbc.EmbeddedDriver</value>
    <description>The JDBC driver for the database that stores temporary Hive statistics.</description>
  </property>
  <property>
    <name>hive.stats.dbconnectionstring</name>
    <value>jdbc:derby:;databaseName=TempStatsStore;create=true</value>
    <description>The default connection string for the database that stores temporary Hive statistics.</description>
  </property>
  <property>
    <name>hive.stats.default.publisher</name>
    <value/>
    <description>The Java class (implementing the StatsPublisher interface) that is used by default if hive.stats.dbclass is custom type.</description>
  </property>
  <property>
    <name>hive.stats.default.aggregator</name>
    <value/>
    <description>The Java class (implementing the StatsAggregator interface) that is used by default if hive.stats.dbclass is custom type.</description>
  </property>
  <property>
    <name>hive.stats.jdbc.timeout</name>
    <value>30s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Timeout value used by JDBC connection and statements.
    </description>
  </property>
  <property>
    <name>hive.stats.atomic</name>
    <value>false</value>
    <description>whether to update metastore stats only if all stats are available</description>
  </property>
  <property>
    <name>hive.stats.retries.max</name>
    <value>0</value>
    <description>
      Maximum number of retries when stats publisher/aggregator got an exception updating intermediate database. 
      Default is no tries on failures.
    </description>
  </property>
  <property>
    <name>hive.stats.retries.wait</name>
    <value>3000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      The base waiting window before the next retry. The actual wait time is calculated by baseWindow * failures baseWindow * (failure + 1) * (random number between [0.0,1.0]).
    </description>
  </property>
  <property>
    <name>hive.stats.collect.rawdatasize</name>
    <value>true</value>
    <description>should the raw data size be collected when analyzing tables</description>
  </property>
  <property>
    <name>hive.client.stats.counters</name>
    <value/>
    <description>
      Subset of counters that should be of interest for hive.client.stats.publishers (when one wants to limit their publishing). 
      Non-display names should be used
    </description>
  </property>
  <property>
    <name>hive.stats.reliable</name>
    <value>false</value>
    <description>
      Whether queries will fail because stats cannot be collected completely accurately. 
      If this is set to true, reading/writing from/into a partition may fail because the stats
      could not be computed accurately.
    </description>
  </property>
  <property>
    <name>hive.analyze.stmt.collect.partlevel.stats</name>
    <value>true</value>
    <description>analyze table T compute statistics for columns. Queries like these should compute partitionlevel stats for partitioned table even when no part spec is specified.</description>
  </property>
  <property>
    <name>hive.stats.gather.num.threads</name>
    <value>10</value>
    <description>
      Number of threads used by partialscan/noscan analyze command for partitioned tables.
      This is applicable only for file formats that implement StatsProvidingRecordReader (like ORC).
    </description>
  </property>
  <property>
    <name>hive.stats.collect.tablekeys</name>
    <value>false</value>
    <description>
      Whether join and group by keys on tables are derived and maintained in the QueryPlan.
      This is useful to identify how tables are accessed and to determine if they should be bucketed.
    </description>
  </property>
  <property>
    <name>hive.stats.collect.scancols</name>
    <value>false</value>
    <description>
      Whether column accesses are tracked in the QueryPlan.
      This is useful to identify how tables are accessed and to determine if there are wasted columns that can be trimmed.
    </description>
  </property>
  <property>
    <name>hive.stats.ndv.error</name>
    <value>20.0</value>
    <description>
      Standard error expressed in percentage. Provides a tradeoff between accuracy and compute cost. 
      A lower value for error indicates higher accuracy and a higher compute cost.
    </description>
  </property>
  <property>
    <name>hive.stats.key.prefix.max.length</name>
    <value>150</value>
    <description>
      Determines if when the prefix of the key used for intermediate stats collection
      exceeds a certain length, a hash of the key is used instead.  If the value < 0 then hashing
    </description>
  </property>
  <property>
    <name>hive.stats.key.prefix.reserve.length</name>
    <value>24</value>
    <description>
      Reserved length for postfix of stats key. Currently only meaningful for counter type which should
      keep length of full stats key smaller than max length configured by hive.stats.key.prefix.max.length.
      For counter type, it should be bigger than the length of LB spec if exists.
    </description>
  </property>
  <property>
    <name>hive.stats.max.variable.length</name>
    <value>100</value>
    <description>
      To estimate the size of data flowing through operators in Hive/Tez(for reducer estimation etc.),
      average row size is multiplied with the total number of rows coming out of each operator.
      Average row size is computed from average column size of all columns in the row. In the absence
      of column statistics, for variable length columns (like string, bytes etc.), this value will be
      used. For fixed length columns their corresponding Java equivalent sizes are used
      (float - 4 bytes, double - 8 bytes etc.).
    </description>
  </property>
  <property>
    <name>hive.stats.list.num.entries</name>
    <value>10</value>
    <description>
      To estimate the size of data flowing through operators in Hive/Tez(for reducer estimation etc.),
      average row size is multiplied with the total number of rows coming out of each operator.
      Average row size is computed from average column size of all columns in the row. In the absence
      of column statistics and for variable length complex columns like list, the average number of
      entries/values can be specified using this config.
    </description>
  </property>
  <property>
    <name>hive.stats.map.num.entries</name>
    <value>10</value>
    <description>
      To estimate the size of data flowing through operators in Hive/Tez(for reducer estimation etc.),
      average row size is multiplied with the total number of rows coming out of each operator.
      Average row size is computed from average column size of all columns in the row. In the absence
      of column statistics and for variable length complex columns like map, the average number of
      entries/values can be specified using this config.
    </description>
  </property>
  <property>
    <name>hive.stats.fetch.partition.stats</name>
    <value>true</value>
    <description>
      Annotation of operator tree with statistics information requires partition level basic
      statistics like number of rows, data size and file size. Partition statistics are fetched from
      metastore. Fetching partition statistics for each needed partition can be expensive when the
      number of partitions is high. This flag can be used to disable fetching of partition statistics
      from metastore. When this flag is disabled, Hive will make calls to filesystem to get file sizes
      and will estimate the number of rows from row schema.
    </description>
  </property>
  <property>
    <name>hive.stats.fetch.column.stats</name>
    <value>false</value>
    <description>
      Annotation of operator tree with statistics information requires column statistics.
      Column statistics are fetched from metastore. Fetching column statistics for each needed column
      can be expensive when the number of columns is high. This flag can be used to disable fetching
      of column statistics from metastore.
    </description>
  </property>
  <property>
    <name>hive.stats.join.factor</name>
    <value>1.1</value>
    <description>
      Hive/Tez optimizer estimates the data size flowing through each of the operators. JOIN operator
      uses column statistics to estimate the number of rows flowing out of it and hence the data size.
      In the absence of column statistics, this factor determines the amount of rows that flows out
      of JOIN operator.
    </description>
  </property>
  <property>
    <name>hive.stats.deserialization.factor</name>
    <value>1.0</value>
    <description>
      Hive/Tez optimizer estimates the data size flowing through each of the operators. In the absence
      of basic statistics like number of rows and data size, file size is used to estimate the number
      of rows and data size. Since files in tables/partitions are serialized (and optionally
      compressed) the estimates of number of rows and data size cannot be reliably determined.
      This factor is multiplied with the file size to account for serialization and compression.
    </description>
  </property>
  <property>
    <name>hive.support.concurrency</name>
    <value>false</value>
    <description>
      Whether Hive supports concurrency control or not. 
      A ZooKeeper instance must be up and running when using zookeeper Hive lock manager 
    </description>
  </property>
  <property>
    <name>hive.lock.manager</name>
    <value>org.apache.hadoop.hive.ql.lockmgr.zookeeper.ZooKeeperHiveLockManager</value>
    <description/>
  </property>
  <property>
    <name>hive.lock.numretries</name>
    <value>100</value>
    <description>The number of times you want to try to get all the locks</description>
  </property>
  <property>
    <name>hive.unlock.numretries</name>
    <value>10</value>
    <description>The number of times you want to retry to do one unlock</description>
  </property>
  <property>
    <name>hive.lock.sleep.between.retries</name>
    <value>60s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      The sleep time between various retries
    </description>
  </property>
  <property>
    <name>hive.lock.mapred.only.operation</name>
    <value>false</value>
    <description>
      This param is to control whether or not only do lock on queries
      that need to execute at least one mapred job.
    </description>
  </property>
  <property>
    <name>hive.zookeeper.quorum</name>
    <value/>
    <description>
      List of ZooKeeper servers to talk to. This is needed for: 
      1. Read/write locks - when hive.lock.manager is set to 
      org.apache.hadoop.hive.ql.lockmgr.zookeeper.ZooKeeperHiveLockManager, 
      2. When HiveServer2 supports service discovery via Zookeeper.
      3. For delegation token storage if zookeeper store is used, if
      hive.cluster.delegation.token.store.zookeeper.connectString is not set
    </description>
  </property>
  <property>
    <name>hive.zookeeper.client.port</name>
    <value>2181</value>
    <description>
      The port of ZooKeeper servers to talk to.
      If the list of Zookeeper servers specified in hive.zookeeper.quorum
      does not contain port numbers, this value is used.
    </description>
  </property>
  <property>
    <name>hive.zookeeper.session.timeout</name>
    <value>600000</value>
    <description>
      ZooKeeper client's session timeout. The client is disconnected, and as a result, all locks released, 
      if a heartbeat is not sent in the timeout.
    </description>
  </property>
  <property>
    <name>hive.zookeeper.namespace</name>
    <value>hive_zookeeper_namespace</value>
    <description>The parent node under which all ZooKeeper nodes are created.</description>
  </property>
  <property>
    <name>hive.zookeeper.clean.extra.nodes</name>
    <value>false</value>
    <description>Clean extra nodes at the end of the session.</description>
  </property>
  <property>
    <name>hive.txn.manager</name>
    <value>org.apache.hadoop.hive.ql.lockmgr.DummyTxnManager</value>
    <description>
      Set to org.apache.hadoop.hive.ql.lockmgr.DbTxnManager as part of turning on Hive
      transactions, which also requires appropriate settings for hive.compactor.initiator.on,
      hive.compactor.worker.threads, hive.support.concurrency (true), hive.enforce.bucketing
      (true), and hive.exec.dynamic.partition.mode (nonstrict).
      The default DummyTxnManager replicates pre-Hive-0.13 behavior and provides
      no transactions.
    </description>
  </property>
  <property>
    <name>hive.txn.timeout</name>
    <value>300s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      time after which transactions are declared aborted if the client has not sent a heartbeat.
    </description>
  </property>
  <property>
    <name>hive.txn.max.open.batch</name>
    <value>1000</value>
    <description>
      Maximum number of transactions that can be fetched in one call to open_txns().
      This controls how many transactions streaming agents such as Flume or Storm open
      simultaneously. The streaming agent then writes that number of entries into a single
      file (per Flume agent or Storm bolt). Thus increasing this value decreases the number
      of delta files created by streaming agents. But it also increases the number of open
      transactions that Hive has to track at any given time, which may negatively affect
      read performance.
    </description>
  </property>
  <property>
    <name>hive.compactor.initiator.on</name>
    <value>false</value>
    <description>
      Whether to run the initiator and cleaner threads on this metastore instance or not.
      Set this to true on one instance of the Thrift metastore service as part of turning
      on Hive transactions. For a complete list of parameters required for turning on
      transactions, see hive.txn.manager.
    </description>
  </property>
  <property>
    <name>hive.compactor.worker.threads</name>
    <value>0</value>
    <description>
      How many compactor worker threads to run on this metastore instance. Set this to a
      positive number on one or more instances of the Thrift metastore service as part of
      turning on Hive transactions. For a complete list of parameters required for turning
      on transactions, see hive.txn.manager.
      Worker threads spawn MapReduce jobs to do compactions. They do not do the compactions
      themselves. Increasing the number of worker threads will decrease the time it takes
      tables or partitions to be compacted once they are determined to need compaction.
      It will also increase the background load on the Hadoop cluster as more MapReduce jobs
      will be running in the background.
    </description>
  </property>
  <property>
    <name>hive.compactor.worker.timeout</name>
    <value>86400s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Time in seconds after which a compaction job will be declared failed and the
      compaction re-queued.
    </description>
  </property>
  <property>
    <name>hive.compactor.check.interval</name>
    <value>300s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Time in seconds between checks to see if any tables or partitions need to be
      compacted. This should be kept high because each check for compaction requires
      many calls against the NameNode.
      Decreasing this value will reduce the time it takes for compaction to be started
      for a table or partition that requires compaction. However, checking if compaction
      is needed requires several calls to the NameNode for each table or partition that
      has had a transaction done on it since the last major compaction. So decreasing this
      value will increase the load on the NameNode.
    </description>
  </property>
  <property>
    <name>hive.compactor.delta.num.threshold</name>
    <value>10</value>
    <description>
      Number of delta directories in a table or partition that will trigger a minor
      compaction.
    </description>
  </property>
  <property>
    <name>hive.compactor.delta.pct.threshold</name>
    <value>0.1</value>
    <description>
      Percentage (fractional) size of the delta files relative to the base that will trigger
      a major compaction. (1.0 = 100%, so the default 0.1 = 10%.)
    </description>
  </property>
  <property>
    <name>hive.compactor.abortedtxn.threshold</name>
    <value>1000</value>
    <description>
      Number of aborted transactions involving a given table or partition that will trigger
      a major compaction.
    </description>
  </property>
  <property>
    <name>hive.compactor.cleaner.run.interval</name>
    <value>5000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Time between runs of the cleaner thread
    </description>
  </property>
  <!--是否開啓 HBase Storage Handler-->
  <property>
    <name>hive.hbase.wal.enabled</name>
    <value>true</value>
    <description>
      Whether writes to HBase should be forced to the write-ahead log. 
      Disabling this improves HBase write performance at the risk of lost writes in case of a crash.
    </description>
  </property>
  <property>
    <name>hive.hbase.generatehfiles</name>
    <value>false</value>
    <description>True when HBaseStorageHandler should generate hfiles instead of operate against the online table.</description>
  </property>
  <property>
    <name>hive.hbase.snapshot.name</name>
    <value/>
    <description>The HBase table snapshot name to use.</description>
  </property>
  <property>
    <name>hive.hbase.snapshot.restoredir</name>
    <value>/tmp</value>
    <description>The directory in which to restore the HBase table snapshot.</description>
  </property>
  <!--是否啓用 har 文件-->
  <property>
    <name>hive.archive.enabled</name>
    <value>false</value>
    <description>Whether archiving operations are permitted</description>
  </property>
  <property>
    <name>hive.optimize.index.groupby</name>
    <value>false</value>
    <description>Whether to enable optimization of group-by queries using Aggregate indexes.</description>
  </property>
  <!--是否啓動外聯接支持過濾條件-->
  <property>
    <name>hive.outerjoin.supports.filters</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>hive.fetch.task.conversion</name>
    <value>more</value>
    <description>
      Expects one of [none, minimal, more].
      Some select queries can be converted to single FETCH task minimizing latency.
      Currently the query should be single sourced not having any subquery and should not have
      any aggregations or distincts (which incurs RS), lateral views and joins.
      0. none : disable hive.fetch.task.conversion
      1. minimal : SELECT STAR, FILTER on partition columns, LIMIT only
      2. more    : SELECT, FILTER, LIMIT only (support TABLESAMPLE and virtual columns)
    </description>
  </property>
  <property>
    <name>hive.fetch.task.conversion.threshold</name>
    <value>1073741824</value>
    <description>
      Input threshold for applying hive.fetch.task.conversion. If target table is native, input length
      is calculated by summation of file lengths. If it's not native, storage handler for the table
      can optionally implement org.apache.hadoop.hive.ql.metadata.InputEstimator interface.
    </description>
  </property>
  <property>
    <name>hive.fetch.task.aggr</name>
    <value>false</value>
    <description>
      Aggregation queries with no group-by clause (for example, select count(*) from src) execute
      final aggregations in single reduce task. If this is set true, Hive delegates final aggregation
      stage to fetch task, possibly decreasing the query time.
    </description>
  </property>
  <property>
    <name>hive.compute.query.using.stats</name>
    <value>false</value>
    <description>
      When set to true Hive will answer a few queries like count(1) purely using stats
      stored in metastore. For basic stats collection turn on the config hive.stats.autogather to true.
      For more advanced stats collection need to run analyze table queries.
    </description>
  </property>
  <!--對於 Fetch Task 的 SerDe類-->
  <property>
    <name>hive.fetch.output.serde</name>
    <value>org.apache.hadoop.hive.serde2.DelimitedJSONSerDe</value>
    <description>The SerDe used by FetchTask to serialize the fetch output.</description>
  </property>
  <property>
    <name>hive.cache.expr.evaluation</name>
    <value>true</value>
    <description>
      If true, the evaluation result of a deterministic expression referenced twice or more
      will be cached.
      For example, in a filter condition like '.. where key + 10 = 100 or key + 10 = 0'
      the expression 'key + 10' will be evaluated/cached once and reused for the following
      expression ('key + 10 = 0'). Currently, this is applied only to expressions in select
      or filter operators.
    </description>
  </property>
  <property>
    <name>hive.variable.substitute</name>
    <value>true</value>
    <description>This enables substitution using syntax like ${var} ${system:var} and ${env:var}.</description>
  </property>
  <property>
    <name>hive.variable.substitute.depth</name>
    <value>40</value>
    <description>The maximum replacements the substitution engine will do.</description>
  </property>
  <property>
    <name>hive.conf.validation</name>
    <value>true</value>
    <description>Enables type checking for registered Hive configurations</description>
  </property>
  <!--Hive 語義分析的 Hook,在語義分析階段的前後被調用,用於分析和修改AST及生成的執行計劃,以逗號分隔-->
  <property>
    <name>hive.semantic.analyzer.hook</name>
    <value/>
    <description/>
  </property>
  <!--是否開啓hive客戶端的權限認證-->
  <property>
    <name>hive.security.authorization.enabled</name>
    <value>false</value>
    <description>enable or disable the Hive client authorization</description>
  </property>
  <property>
    <name>hive.security.authorization.manager</name>
    <value>org.apache.hadoop.hive.ql.security.authorization.DefaultHiveAuthorizationProvider</value>
    <description>
      The Hive client authorization manager class name. The user defined authorization class should implement 
      interface org.apache.hadoop.hive.ql.security.authorization.HiveAuthorizationProvider.
    </description>
  </property>
  <property>
    <name>hive.security.authenticator.manager</name>
    <value>org.apache.hadoop.hive.ql.security.HadoopDefaultAuthenticator</value>
    <description>
      hive client authenticator manager class name. The user defined authenticator should implement 
      interface org.apache.hadoop.hive.ql.security.HiveAuthenticationProvider.
    </description>
  </property>
  <property>
    <name>hive.security.metastore.authorization.manager</name>
    <value>org.apache.hadoop.hive.ql.security.authorization.DefaultHiveMetastoreAuthorizationProvider</value>
    <description>
      Names of authorization manager classes (comma separated) to be used in the metastore
      for authorization. The user defined authorization class should implement interface
      org.apache.hadoop.hive.ql.security.authorization.HiveMetastoreAuthorizationProvider.
      All authorization manager classes have to successfully authorize the metastore API
      call for the command execution to be allowed.
    </description>
  </property>
  <property>
    <name>hive.security.metastore.authorization.auth.reads</name>
    <value>true</value>
    <description>If this is true, metastore authorizer authorizes read actions on database, table</description>
  </property>
  <property>
    <name>hive.security.metastore.authenticator.manager</name>
    <value>org.apache.hadoop.hive.ql.security.HadoopDefaultMetastoreAuthenticator</value>
    <description>
      authenticator manager class name to be used in the metastore for authentication. 
      The user defined authenticator should implement interface org.apache.hadoop.hive.ql.security.HiveAuthenticationProvider.
    </description>
  </property>
  <property>
    <name>hive.security.authorization.createtable.user.grants</name>
    <value/>
    <description>
      the privileges automatically granted to some users whenever a table gets created.
      An example like "userX,userY:select;userZ:create" will grant select privilege to userX and userY,
      and grant create privilege to userZ whenever a new table created.
    </description>
  </property>
  <property>
    <name>hive.security.authorization.createtable.group.grants</name>
    <value/>
    <description>
      the privileges automatically granted to some groups whenever a table gets created.
      An example like "groupX,groupY:select;groupZ:create" will grant select privilege to groupX and groupY,
      and grant create privilege to groupZ whenever a new table created.
    </description>
  </property>
  <property>
    <name>hive.security.authorization.createtable.role.grants</name>
    <value/>
    <description>
      the privileges automatically granted to some roles whenever a table gets created.
      An example like "roleX,roleY:select;roleZ:create" will grant select privilege to roleX and roleY,
      and grant create privilege to roleZ whenever a new table created.
    </description>
  </property>
  <property>
    <name>hive.security.authorization.createtable.owner.grants</name>
    <value/>
    <description>
      The privileges automatically granted to the owner whenever a table gets created.
      An example like "select,drop" will grant select and drop privilege to the owner
      of the table. Note that the default gives the creator of a table no access to the
      table (but see HIVE-8067).
    </description>
  </property>
  <property>
    <name>hive.security.authorization.sqlstd.confwhitelist</name>
    <value/>
    <description>
      List of comma separated Java regexes. Configurations parameters that match these
      regexes can be modified by user when SQL standard authorization is enabled.
      To get the default value, use the 'set <param>' command.
      Note that the hive.conf.restricted.list checks are still enforced after the white list
      check
    </description>
  </property>
  <property>
    <name>hive.security.authorization.sqlstd.confwhitelist.append</name>
    <value/>
    <description>
      List of comma separated Java regexes, to be appended to list set in
      hive.security.authorization.sqlstd.confwhitelist. Using this list instead
      of updating the original list means that you can append to the defaults
      set by SQL standard authorization instead of replacing it entirely.
    </description>
  </property>
  <!--是否顯示查詢結果的列名,默認爲不顯示-->
  <property>
    <name>hive.cli.print.header</name>
    <value>false</value>
    <description>Whether to print the names of the columns in query output.</description>
  </property>
  <!--Hive 默認的命令行字符編碼-->
  <property>
    <name>hive.cli.encoding</name>
    <value>UTF8</value>
  </property>
  <!--是否記錄執行計劃的進度-->
  <property>
    <name>hive.log.plan.progress</name>
    <value>true</value>
  </property>
  <property>
    <name>hive.error.on.empty.partition</name>
    <value>false</value>
    <description>Whether to throw an exception if dynamic partition insert generates empty results.</description>
  </property>
  <property>
    <name>hive.index.compact.file</name>
    <value/>
    <description>internal variable</description>
  </property>
  <property>
    <name>hive.index.blockfilter.file</name>
    <value/>
    <description>internal variable</description>
  </property>
  <property>
    <name>hive.index.compact.file.ignore.hdfs</name>
    <value>false</value>
    <description>
      When true the HDFS location stored in the index file will be ignored at runtime.
      If the data got moved or the name of the cluster got changed, the index data should still be usable.
    </description>
  </property>
  <property>
    <name>hive.exim.uri.scheme.whitelist</name>
    <value>hdfs,pfile</value>
    <description>A comma separated list of acceptable URI schemes for import and export.</description>
  </property>
  <property>
    <name>hive.mapper.cannot.span.multiple.partitions</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.rework.mapredwork</name>
    <value>false</value>
    <description>
      should rework the mapred work or not.
      This is first introduced by SymlinkTextInputFormat to replace symlink files with real paths at compile time.
    </description>
  </property>
  <property>
    <name>hive.exec.concatenate.check.index</name>
    <value>true</value>
    <description>
      If this is set to true, Hive will throw error when doing
      'alter table tbl_name [partSpec] concatenate' on a table/partition
      that has indexes on it. The reason the user want to set this to true
      is because it can help user to avoid handling all index drop, recreation,
      rebuild work. This is very helpful for tables with thousands of partitions.
    </description>
  </property>
  <property>
    <name>hive.io.exception.handlers</name>
    <value/>
    <description>
      A list of io exception handler class names. This is used
      to construct a list exception handlers to handle exceptions thrown
      by record readers
    </description>
  </property>
  <property>
    <name>hive.server2.logging.operation.enabled</name>
    <value>true</value>
    <description>When true, HS2 will save operation logs and make them available for clients</description>
  </property>
  <property>
    <name>hive.server2.logging.operation.log.location</name>
    <value>${system:java.io.tmpdir}/${system:user.name}/operation_logs</value>
    <description>Top level directory where operation logs are stored if logging functionality is enabled</description>
  </property>
  <property>
    <name>hive.server2.logging.operation.verbose</name>
    <value>false</value>
    <description>When true, HS2 operation logs available for clients will be verbose</description>
  </property>
  <property>
    <name>hive.log4j.file</name>
    <value/>
    <description>
      Hive log4j configuration file.
      If the property is not set, then logging will be initialized using hive-log4j.properties found on the classpath.
      If the property is set, the value must be a valid URI (java.net.URI, e.g. "file:///tmp/my-logging.properties"), 
      which you can then extract a URL from and pass to PropertyConfigurator.configure(URL).
    </description>
  </property>
  <property>
    <name>hive.exec.log4j.file</name>
    <value/>
    <description>
      Hive log4j configuration file for execution mode(sub command).
      If the property is not set, then logging will be initialized using hive-exec-log4j.properties found on the classpath.
      If the property is set, the value must be a valid URI (java.net.URI, e.g. "file:///tmp/my-logging.properties"), 
      which you can then extract a URL from and pass to PropertyConfigurator.configure(URL).
    </description>
  </property>
  <property>
    <name>hive.autogen.columnalias.prefix.label</name>
    <value>_c</value>
    <description>
      String used as a prefix when auto generating column alias.
      By default the prefix label will be appended with a column position number to form the column alias. 
      Auto generation would happen if an aggregate function is used in a select clause without an explicit alias.
    </description>
  </property>
  <property>
    <name>hive.autogen.columnalias.prefix.includefuncname</name>
    <value>false</value>
    <description>Whether to include function name in the column alias auto generated by Hive.</description>
  </property>
  <property>
    <name>hive.exec.perf.logger</name>
    <value>org.apache.hadoop.hive.ql.log.PerfLogger</value>
    <description>
      The class responsible for logging client side performance metrics. 
      Must be a subclass of org.apache.hadoop.hive.ql.log.PerfLogger
    </description>
  </property>
  <property>
    <name>hive.start.cleanup.scratchdir</name>
    <value>false</value>
    <description>To cleanup the Hive scratchdir when starting the Hive Server</description>
  </property>
  <property>
    <name>hive.insert.into.multilevel.dirs</name>
    <value>false</value>
    <description>
      Where to insert into multilevel directories like
      "insert directory '/HIVEFT25686/chinna/' from table"
    </description>
  </property>
  <property>
    <name>hive.warehouse.subdir.inherit.perms</name>
    <value>false</value>
    <description>
      Set this to true if the the table directories should inherit the
      permission of the warehouse or database directory instead of being created
      with the permissions derived from dfs umask
    </description>
  </property>
  <property>
    <name>hive.insert.into.external.tables</name>
    <value>true</value>
    <description>whether insert into external tables is allowed</description>
  </property>
  <property>
    <name>hive.exec.driver.run.hooks</name>
    <value/>
    <description>A comma separated list of hooks which implement HiveDriverRunHook. Will be run at the beginning and end of Driver.run, these will be run in the order specified.</description>
  </property>
  <property>
    <name>hive.ddl.output.format</name>
    <value/>
    <description>
      The data format to use for DDL output.  One of "text" (for human
      readable text) or "json" (for a json object).
    </description>
  </property>
  <property>
    <name>hive.entity.separator</name>
    <value>@</value>
    <description>Separator used to construct names of tables and partitions. For example, dbname@tablename@partitionname</description>
  </property>
  <property>
    <name>hive.display.partition.cols.separately</name>
    <value>true</value>
    <description>
      In older Hive version (0.10 and earlier) no distinction was made between
      partition columns or non-partition columns while displaying columns in describe
      table. From 0.12 onwards, they are displayed separately. This flag will let you
      get old behavior, if desired. See, test-case in patch for HIVE-6689.
    </description>
  </property>
  <property>
    <name>hive.ssl.protocol.blacklist</name>
    <value>SSLv2,SSLv2Hello,SSLv3</value>
    <description>SSL Versions to disable for all Hive Servers</description>
  </property>
  <property>
    <name>hive.server2.max.start.attempts</name>
    <value>30</value>
    <description>
      Expects value bigger than 0.
      Number of times HiveServer2 will attempt to start before exiting, sleeping 60 seconds between retries. 
       The default of 30 will keep trying for 30 minutes.
    </description>
  </property>
  <property>
    <name>hive.server2.support.dynamic.service.discovery</name>
    <value>false</value>
    <description>Whether HiveServer2 supports dynamic service discovery for its clients. To support this, each instance of HiveServer2 currently uses ZooKeeper to register itself, when it is brought up. JDBC/ODBC clients should use the ZooKeeper ensemble: hive.zookeeper.quorum in their connection string.</description>
  </property>
  <property>
    <name>hive.server2.zookeeper.namespace</name>
    <value>hiveserver2</value>
    <description>The parent node in ZooKeeper used by HiveServer2 when supporting dynamic service discovery.</description>
  </property>
  <property>
    <name>hive.server2.global.init.file.location</name>
    <value>${env:HIVE_CONF_DIR}</value>
    <description>
      Either the location of a HS2 global init file or a directory containing a .hiverc file. If the 
      property is set, the value must be a valid path to an init file or directory where the init file is located.
    </description>
  </property>
  <property>
    <name>hive.server2.transport.mode</name>
    <value>binary</value>
    <description>
      Expects one of [binary, http].
      Transport mode of HiveServer2.
    </description>
  </property>
  <property>
    <name>hive.server2.thrift.bind.host</name>
    <value/>
    <description>Bind host on which to run the HiveServer2 Thrift service.</description>
  </property>
  <property>
    <name>hive.server2.thrift.http.port</name>
    <value>10001</value>
    <description>Port number of HiveServer2 Thrift interface when hive.server2.transport.mode is 'http'.</description>
  </property>
  <property>
    <name>hive.server2.thrift.http.path</name>
    <value>cliservice</value>
    <description>Path component of URL endpoint when in HTTP mode.</description>
  </property>
  <property>
    <name>hive.server2.thrift.http.min.worker.threads</name>
    <value>5</value>
    <description>Minimum number of worker threads when in HTTP mode.</description>
  </property>
  <property>
    <name>hive.server2.thrift.http.max.worker.threads</name>
    <value>500</value>
    <description>Maximum number of worker threads when in HTTP mode.</description>
  </property>
  <property>
    <name>hive.server2.thrift.http.max.idle.time</name>
    <value>1800s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Maximum idle time for a connection on the server when in HTTP mode.
    </description>
  </property>
  <property>
    <name>hive.server2.thrift.http.worker.keepalive.time</name>
    <value>60s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Keepalive time for an idle http worker thread. When the number of workers exceeds min workers, excessive threads are killed after this time interval.
    </description>
  </property>
  <property>
    <name>hive.server2.thrift.port</name>
    <value>10000</value>
    <description>Port number of HiveServer2 Thrift interface when hive.server2.transport.mode is 'binary'.</description>
  </property>
  <property>
    <name>hive.server2.thrift.sasl.qop</name>
    <value>auth</value>
    <description>
      Expects one of [auth, auth-int, auth-conf].
      Sasl QOP value; set it to one of following values to enable higher levels of
      protection for HiveServer2 communication with clients.
      Setting hadoop.rpc.protection to a higher level than HiveServer2 does not
      make sense in most situations. HiveServer2 ignores hadoop.rpc.protection in favor
      of hive.server2.thrift.sasl.qop.
        "auth" - authentication only (default)
        "auth-int" - authentication plus integrity protection
        "auth-conf" - authentication plus integrity and confidentiality protection
      This is applicable only if HiveServer2 is configured to use Kerberos authentication.
    </description>
  </property>
  <property>
    <name>hive.server2.thrift.min.worker.threads</name>
    <value>5</value>
    <description>Minimum number of Thrift worker threads</description>
  </property>
  <property>
    <name>hive.server2.thrift.max.worker.threads</name>
    <value>500</value>
    <description>Maximum number of Thrift worker threads</description>
  </property>
  <property>
    <name>hive.server2.thrift.worker.keepalive.time</name>
    <value>60s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Keepalive time (in seconds) for an idle worker thread. When the number of workers exceeds min workers, excessive threads are killed after this time interval.
    </description>
  </property>
  <property>
    <name>hive.server2.async.exec.threads</name>
    <value>100</value>
    <description>Number of threads in the async thread pool for HiveServer2</description>
  </property>
  <property>
    <name>hive.server2.async.exec.shutdown.timeout</name>
    <value>10s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      How long HiveServer2 shutdown will wait for async threads to terminate.
    </description>
  </property>
  <property>
    <name>hive.server2.async.exec.wait.queue.size</name>
    <value>100</value>
    <description>
      Size of the wait queue for async thread pool in HiveServer2.
      After hitting this limit, the async thread pool will reject new requests.
    </description>
  </property>
  <property>
    <name>hive.server2.async.exec.keepalive.time</name>
    <value>10s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Time that an idle HiveServer2 async thread (from the thread pool) will wait for a new task
      to arrive before terminating
    </description>
  </property>
  <property>
    <name>hive.server2.long.polling.timeout</name>
    <value>5000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Time that HiveServer2 will wait before responding to asynchronous calls that use long polling
    </description>
  </property>
  <property>
    <name>hive.server2.authentication</name>
    <value>NONE</value>
    <description>
      Expects one of [nosasl, none, ldap, kerberos, pam, custom].
      Client authentication types.
        NONE: no authentication check
        LDAP: LDAP/AD based authentication
        KERBEROS: Kerberos/GSSAPI authentication
        CUSTOM: Custom authentication provider
                (Use with property hive.server2.custom.authentication.class)
        PAM: Pluggable authentication module
        NOSASL:  Raw transport
    </description>
  </property>
  <property>
    <name>hive.server2.allow.user.substitution</name>
    <value>true</value>
    <description>Allow alternate user to be specified as part of HiveServer2 open connection request.</description>
  </property>
  <property>
    <name>hive.server2.authentication.kerberos.keytab</name>
    <value/>
    <description>Kerberos keytab file for server principal</description>
  </property>
  <property>
    <name>hive.server2.authentication.kerberos.principal</name>
    <value/>
    <description>Kerberos server principal</description>
  </property>
  <property>
    <name>hive.server2.authentication.spnego.keytab</name>
    <value/>
    <description>
      keytab file for SPNego principal, optional,
      typical value would look like /etc/security/keytabs/spnego.service.keytab,
      This keytab would be used by HiveServer2 when Kerberos security is enabled and 
      HTTP transport mode is used.
      This needs to be set only if SPNEGO is to be used in authentication.
      SPNego authentication would be honored only if valid
        hive.server2.authentication.spnego.principal
      and
        hive.server2.authentication.spnego.keytab
      are specified.
    </description>
  </property>
  <property>
    <name>hive.server2.authentication.spnego.principal</name>
    <value/>
    <description>
      SPNego service principal, optional,
      typical value would look like HTTP/[email protected]
      SPNego service principal would be used by HiveServer2 when Kerberos security is enabled
      and HTTP transport mode is used.
      This needs to be set only if SPNEGO is to be used in authentication.
    </description>
  </property>
  <property>
    <name>hive.server2.authentication.ldap.url</name>
    <value/>
    <description>LDAP connection URL</description>
  </property>
  <property>
    <name>hive.server2.authentication.ldap.baseDN</name>
    <value/>
    <description>LDAP base DN</description>
  </property>
  <property>
    <name>hive.server2.authentication.ldap.Domain</name>
    <value/>
    <description/>
  </property>
  <property>
    <name>hive.server2.custom.authentication.class</name>
    <value/>
    <description>
      Custom authentication class. Used when property
      'hive.server2.authentication' is set to 'CUSTOM'. Provided class
      must be a proper implementation of the interface
      org.apache.hive.service.auth.PasswdAuthenticationProvider. HiveServer2
      will call its Authenticate(user, passed) method to authenticate requests.
      The implementation may optionally implement Hadoop's
      org.apache.hadoop.conf.Configurable class to grab Hive's Configuration object.
    </description>
  </property>
  <property>
    <name>hive.server2.authentication.pam.services</name>
    <value/>
    <description>
      List of the underlying pam services that should be used when auth type is PAM
      A file with the same name must exist in /etc/pam.d
    </description>
  </property>
  <property>
    <name>hive.server2.enable.doAs</name>
    <value>true</value>
    <description>
      Setting this property to true will have HiveServer2 execute
      Hive operations as the user making the calls to it.
    </description>
  </property>
  <property>
    <name>hive.server2.table.type.mapping</name>
    <value>CLASSIC</value>
    <description>
      Expects one of [classic, hive].
      This setting reflects how HiveServer2 will report the table types for JDBC and other
      client implementations that retrieve the available tables and supported table types
        HIVE : Exposes Hive's native table types like MANAGED_TABLE, EXTERNAL_TABLE, VIRTUAL_VIEW
        CLASSIC : More generic types like TABLE and VIEW
    </description>
  </property>
  <property>
    <name>hive.server2.session.hook</name>
    <value/>
    <description/>
  </property>
  <property>
    <name>hive.server2.use.SSL</name>
    <value>false</value>
    <description>Set this to true for using SSL encryption in HiveServer2.</description>
  </property>
  <property>
    <name>hive.server2.keystore.path</name>
    <value/>
    <description>SSL certificate keystore location.</description>
  </property>
  <property>
    <name>hive.server2.keystore.password</name>
    <value/>
    <description>SSL certificate keystore password.</description>
  </property>
  <property>
    <name>hive.security.command.whitelist</name>
    <value>set,reset,dfs,add,list,delete,reload,compile</value>
    <description>Comma separated list of non-SQL Hive commands users are authorized to execute</description>
  </property>
  <property>
    <name>hive.server2.session.check.interval</name>
    <value>0ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      The time should be bigger than or equal to 3000 msec.
      The check interval for session/operation timeout, which can be disabled by setting to zero or negative value.
    </description>
  </property>
  <property>
    <name>hive.server2.idle.session.timeout</name>
    <value>0ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Session will be closed when it's not accessed for this duration, which can be disabled by setting to zero or negative value.
    </description>
  </property>
  <property>
    <name>hive.server2.idle.operation.timeout</name>
    <value>0ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Operation will be closed when it's not accessed for this duration of time, which can be disabled by setting to zero value.
        With positive value, it's checked for operations in terminal state only (FINISHED, CANCELED, CLOSED, ERROR).
        With negative value, it's checked for all of the operations regardless of state.
    </description>
  </property>
  <property>
    <name>hive.conf.restricted.list</name>
    <value>hive.security.authenticator.manager,hive.security.authorization.manager,hive.users.in.admin.role</value>
    <description>Comma separated list of configuration options which are immutable at runtime</description>
  </property>
  <property>
    <name>hive.multi.insert.move.tasks.share.dependencies</name>
    <value>false</value>
    <description>
      If this is set all move tasks for tables/partitions (not directories) at the end of a
      multi-insert query will only begin once the dependencies for all these move tasks have been
      met.
      Advantages: If concurrency is enabled, the locks will only be released once the query has
                  finished, so with this config enabled, the time when the table/partition is
                  generated will be much closer to when the lock on it is released.
      Disadvantages: If concurrency is not enabled, with this disabled, the tables/partitions which
                     are produced by this query and finish earlier will be available for querying
                     much earlier.  Since the locks are only released once the query finishes, this
                     does not apply if concurrency is enabled.
    </description>
  </property>
  <property>
    <name>hive.exec.infer.bucket.sort</name>
    <value>false</value>
    <description>
      If this is set, when writing partitions, the metadata will include the bucketing/sorting
      properties with which the data was written if any (this will not overwrite the metadata
      inherited from the table if the table is bucketed/sorted)
    </description>
  </property>
  <property>
    <name>hive.exec.infer.bucket.sort.num.buckets.power.two</name>
    <value>false</value>
    <description>
      If this is set, when setting the number of reducers for the map reduce task which writes the
      final output files, it will choose a number which is a power of two, unless the user specifies
      the number of reducers to use using mapred.reduce.tasks.  The number of reducers
      may be set to a power of two, only to be followed by a merge task meaning preventing
      anything from being inferred.
      With hive.exec.infer.bucket.sort set to true:
      Advantages:  If this is not set, the number of buckets for partitions will seem arbitrary,
                   which means that the number of mappers used for optimized joins, for example, will
                   be very low.  With this set, since the number of buckets used for any partition is
                   a power of two, the number of mappers used for optimized joins will be the least
                   number of buckets used by any partition being joined.
      Disadvantages: This may mean a much larger or much smaller number of reducers being used in the
                     final map reduce job, e.g. if a job was originally going to take 257 reducers,
                     it will now take 512 reducers, similarly if the max number of reducers is 511,
                     and a job was going to use this many, it will now use 256 reducers.
    </description>
  </property>
  <property>
    <name>hive.optimize.listbucketing</name>
    <value>false</value>
    <description>Enable list bucketing optimizer. Default value is false so that we disable it by default.</description>
  </property>
  <property>
    <name>hive.server.read.socket.timeout</name>
    <value>10s</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is sec if not specified.
      Timeout for the HiveServer to close the connection if no response from the client. By default, 10 seconds.
    </description>
  </property>
  <property>
    <name>hive.server.tcp.keepalive</name>
    <value>true</value>
    <description>Whether to enable TCP keepalive for the Hive Server. Keepalive will prevent accumulation of half-open connections.</description>
  </property>
  <property>
    <name>hive.decode.partition.name</name>
    <value>false</value>
    <description>Whether to show the unquoted partition names in query results.</description>
  </property>
  <property>
    <name>hive.execution.engine</name>
    <value>mr</value>
    <description>
      Expects one of [mr, tez].
      Chooses execution engine. Options are: mr (Map reduce, default) or tez (hadoop 2 only)
    </description>
  </property>
  <property>
    <name>hive.jar.directory</name>
    <value/>
    <description>
      This is the location hive in tez mode will look for to find a site wide 
      installed hive instance.
    </description>
  </property>
  <property>
    <name>hive.user.install.directory</name>
    <value>hdfs:///user/</value>
    <description>
      If hive (in tez mode only) cannot find a usable hive jar in "hive.jar.directory", 
      it will upload the hive jar to "hive.user.install.directory/user.name"
      and use it to run queries.
    </description>
  </property>
  <property>
    <name>hive.vectorized.execution.enabled</name>
    <value>false</value>
    <description>
      This flag should be set to true to enable vectorized mode of query execution.
      The default value is false.
    </description>
  </property>
  <property>
    <name>hive.vectorized.execution.reduce.enabled</name>
    <value>true</value>
    <description>
      This flag should be set to true to enable vectorized mode of the reduce-side of query execution.
      The default value is true.
    </description>
  </property>
  <property>
    <name>hive.vectorized.execution.reduce.groupby.enabled</name>
    <value>true</value>
    <description>
      This flag should be set to true to enable vectorized mode of the reduce-side GROUP BY query execution.
      The default value is true.
    </description>
  </property>
  <property>
    <name>hive.vectorized.groupby.checkinterval</name>
    <value>100000</value>
    <description>Number of entries added to the group by aggregation hash before a recomputation of average entry size is performed.</description>
  </property>
  <property>
    <name>hive.vectorized.groupby.maxentries</name>
    <value>1000000</value>
    <description>
      Max number of entries in the vector group by aggregation hashtables. 
      Exceeding this will trigger a flush irrelevant of memory pressure condition.
    </description>
  </property>
  <property>
    <name>hive.vectorized.groupby.flush.percent</name>
    <value>0.1</value>
    <description>Percent of entries in the group by aggregation hash flushed when the memory threshold is exceeded.</description>
  </property>
  <property>
    <name>hive.typecheck.on.insert</name>
    <value>true</value>
    <description/>
  </property>
  <property>
    <name>hive.hadoop.classpath</name>
    <value/>
    <description>
      For Windows OS, we need to pass HIVE_HADOOP_CLASSPATH Java parameter while starting HiveServer2 
      using "-hiveconf hive.hadoop.classpath=%HIVE_LIB%".
    </description>
  </property>
  <property>
    <name>hive.rpc.query.plan</name>
    <value>false</value>
    <description>Whether to send the query plan via local resource or RPC</description>
  </property>
  <property>
    <name>hive.compute.splits.in.am</name>
    <value>true</value>
    <description>Whether to generate the splits locally or in the AM (tez only)</description>
  </property>
  <property>
    <name>hive.prewarm.enabled</name>
    <value>false</value>
    <description>Enables container prewarm for Tez (Hadoop 2 only)</description>
  </property>
  <property>
    <name>hive.prewarm.numcontainers</name>
    <value>10</value>
    <description>Controls the number of containers to prewarm for Tez (Hadoop 2 only)</description>
  </property>
  <property>
    <name>hive.stageid.rearrange</name>
    <value>none</value>
    <description>
      Expects one of [none, idonly, traverse, execution].
    </description>
  </property>
  <property>
    <name>hive.explain.dependency.append.tasktype</name>
    <value>false</value>
    <description/>
  </property>
  <property>
    <name>hive.counters.group.name</name>
    <value>HIVE</value>
    <description>The name of counter group for internal Hive variables (CREATED_FILE, FATAL_ERROR, etc.)</description>
  </property>
  <property>
    <name>hive.server2.tez.default.queues</name>
    <value/>
    <description>
      A list of comma separated values corresponding to YARN queues of the same name.
      When HiveServer2 is launched in Tez mode, this configuration needs to be set
      for multiple Tez sessions to run in parallel on the cluster.
    </description>
  </property>
  <property>
    <name>hive.server2.tez.sessions.per.default.queue</name>
    <value>1</value>
    <description>
      A positive integer that determines the number of Tez sessions that should be
      launched on each of the queues specified by "hive.server2.tez.default.queues".
      Determines the parallelism on each queue.
    </description>
  </property>
  <property>
    <name>hive.server2.tez.initialize.default.sessions</name>
    <value>false</value>
    <description>
      This flag is used in HiveServer2 to enable a user to use HiveServer2 without
      turning on Tez for HiveServer2. The user could potentially want to run queries
      over Tez without the pool of sessions.
    </description>
  </property>
  <property>
    <name>hive.support.quoted.identifiers</name>
    <value>column</value>
    <description>
      Expects one of [none, column].
      Whether to use quoted identifier. 'none' or 'column' can be used. 
        none: default(past) behavior. Implies only alphaNumeric and underscore are valid characters in identifiers.
        column: implies column names can contain any character.
    </description>
  </property>
  <property>
    <name>hive.users.in.admin.role</name>
    <value/>
    <description>
      Comma separated list of users who are in admin role for bootstrapping.
      More users can be added in ADMIN role later.
    </description>
  </property>
  <property>
    <name>hive.compat</name>
    <value>0.12</value>
    <description>
      Enable (configurable) deprecated behaviors by setting desired level of backward compatibility.
      Setting to 0.12:
        Maintains division behavior: int / int = double
    </description>
  </property>
  <property>
    <name>hive.convert.join.bucket.mapjoin.tez</name>
    <value>false</value>
    <description>
      Whether joins can be automatically converted to bucket map joins in hive 
      when tez is used as the execution engine.
    </description>
  </property>
  <property>
    <name>hive.exec.check.crossproducts</name>
    <value>true</value>
    <description>Check if a plan contains a Cross Product. If there is one, output a warning to the Session's console.</description>
  </property>
  <property>
    <name>hive.localize.resource.wait.interval</name>
    <value>5000ms</value>
    <description>
      Expects a time value with unit (d/day, h/hour, m/min, s/sec, ms/msec, us/usec, ns/nsec), which is msec if not specified.
      Time to wait for another thread to localize the same resource for hive-tez.
    </description>
  </property>
  <property>
    <name>hive.localize.resource.num.wait.attempts</name>
    <value>5</value>
    <description>The number of attempts waiting for localizing a resource in hive-tez.</description>
  </property>
  <property>
    <name>hive.tez.auto.reducer.parallelism</name>
    <value>false</value>
    <description>
      Turn on Tez' auto reducer parallelism feature. When enabled, Hive will still estimate data sizes
      and set parallelism estimates. Tez will sample source vertices' output sizes and adjust the estimates at runtime as
      necessary.
    </description>
  </property>
  <property>
    <name>hive.tez.max.partition.factor</name>
    <value>2.0</value>
    <description>When auto reducer parallelism is enabled this factor will be used to over-partition data in shuffle edges.</description>
  </property>
  <property>
    <name>hive.tez.min.partition.factor</name>
    <value>0.25</value>
    <description>
      When auto reducer parallelism is enabled this factor will be used to put a lower limit to the number
      of reducers that tez specifies.
    </description>
  </property>
  <property>
    <name>hive.tez.dynamic.partition.pruning</name>
    <value>true</value>
    <description>
      When dynamic pruning is enabled, joins on partition keys will be processed by sending
      events from the processing vertices to the Tez application master. These events will be
      used to prune unnecessary partitions.
    </description>
  </property>
  <property>
    <name>hive.tez.dynamic.partition.pruning.max.event.size</name>
    <value>1048576</value>
    <description>Maximum size of events sent by processors in dynamic pruning. If this size is crossed no pruning will take place.</description>
  </property>
  <property>
    <name>hive.tez.dynamic.partition.pruning.max.data.size</name>
    <value>104857600</value>
    <description>Maximum total data size of events in dynamic pruning.</description>
  </property>
  <property>
    <name>hive.tez.smb.number.waves</name>
    <value>0.5</value>
    <description>The number of waves in which to run the SMB join. Account for cluster being occupied. Ideally should be 1 wave.</description>
  </property>
  <property>
    <name>hive.tez.exec.print.summary</name>
    <value>false</value>
    <description>Display breakdown of execution steps, for every query executed by the shell.</description>
  </property>
  <property>
    <name>hive.tez.exec.inplace.progress</name>
    <value>true</value>
    <description>Updates tez job execution progress in-place in the terminal.</description>
  </property>
</configuration>



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