mapred.reduce.tasks -1 The default number of reduce tasks per job. Typically set to a prime close to the number of available hosts. Ignored when mapred.job.tracker is "local". Hadoop set this to 1 by default, whereas hive uses -1 as its default value. By setting this property to -1, Hive will automatically figure out what should be the number of reducers. hive.exec.reducers.bytes.per.reducer 1000000000 size per reducer.The default is 1G, i.e if the input size is 10G, it will use 10 reducers. hive.exec.reducers.max 999 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. hive.cli.print.header false Whether to print the names of the columns in query output. hive.cli.print.current.db false Whether to include the current database in the hive prompt. hive.cli.prompt hive 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. hive.cli.pretty.output.num.cols -1 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. hive.exec.scratchdir /tmp/hive-${user.name} Scratch space for Hive jobs hive.exec.local.scratchdir /tmp/${user.name} Local scratch space for Hive jobs hive.test.mode false whether hive is running in test mode. If yes, it turns on sampling and prefixes the output tablename hive.test.mode.prefix test_ if hive is running in test mode, prefixes the output table by this string hive.test.mode.samplefreq 32 if hive is running in test mode and table is not bucketed, sampling frequency hive.test.mode.nosamplelist if hive is running in test mode, dont sample the above comma seperated list of tables hive.metastore.uris Thrift uri for the remote metastore. Used by metastore client to connect to remote metastore. javax.jdo.option.ConnectionURL jdbc:derby:;databaseName=metastore_db;create=true JDBC connect string for a JDBC metastore javax.jdo.option.ConnectionDriverName org.apache.derby.jdbc.EmbeddedDriver Driver class name for a JDBC metastore javax.jdo.PersistenceManagerFactoryClass org.datanucleus.jdo.JDOPersistenceManagerFactory class implementing the jdo persistence javax.jdo.option.DetachAllOnCommit true detaches all objects from session so that they can be used after transaction is committed javax.jdo.option.NonTransactionalRead true reads outside of transactions javax.jdo.option.ConnectionUserName APP username to use against metastore database javax.jdo.option.ConnectionPassword mine password to use against metastore database javax.jdo.option.Multithreaded true Set this to true if multiple threads access metastore through JDO concurrently. datanucleus.connectionPoolingType DBCP Uses a DBCP connection pool for JDBC metastore datanucleus.validateTables false validates existing schema against code. turn this on if you want to verify existing schema datanucleus.validateColumns false validates existing schema against code. turn this on if you want to verify existing schema datanucleus.validateConstraints false validates existing schema against code. turn this on if you want to verify existing schema datanucleus.storeManagerType rdbms metadata store type datanucleus.autoCreateSchema true creates necessary schema on a startup if one doesn't exist. set this to false, after creating it once datanucleus.autoStartMechanismMode checked throw exception if metadata tables are incorrect datanucleus.transactionIsolation read-committed Default transaction isolation level for identity generation. datanucleus.cache.level2 false Use a level 2 cache. Turn this off if metadata is changed independently of hive metastore server datanucleus.cache.level2.type SOFT SOFT=soft reference based cache, WEAK=weak reference based cache. datanucleus.identifierFactory datanucleus Name of the identifier factory to use when generating table/column names etc. 'datanucleus' is used for backward compatibility datanucleus.plugin.pluginRegistryBundleCheck LOG Defines what happens when plugin bundles are found and are duplicated [EXCEPTION|LOG|NONE] hive.metastore.warehouse.dir /user/hive/warehouse location of default database for the warehouse hive.metastore.execute.setugi false 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. hive.metastore.event.listeners list of comma seperated listeners for metastore events. hive.metastore.partition.inherit.table.properties list of comma seperated keys occurring in table properties which will get inherited to newly created partitions. * implies all the keys will get inherited. hive.metadata.export.location 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. hive.metadata.move.exported.metadata.to.trash 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. hive.metastore.partition.name.whitelist.pattern Partition names will be checked against this regex pattern and rejected if not matched. hive.metastore.end.function.listeners list of comma separated listeners for the end of metastore functions. hive.metastore.event.expiry.duration 0 Duration after which events expire from events table (in seconds) hive.metastore.event.clean.freq 0 Frequency at which timer task runs to purge expired events in metastore(in seconds). hive.metastore.connect.retries 5 Number of retries while opening a connection to metastore hive.metastore.failure.retries 3 Number of retries upon failure of Thrift metastore calls hive.metastore.client.connect.retry.delay 1 Number of seconds for the client to wait between consecutive connection attempts hive.metastore.client.socket.timeout 20 MetaStore Client socket timeout in seconds hive.metastore.rawstore.impl org.apache.hadoop.hive.metastore.ObjectStore 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 hive.metastore.batch.retrieve.max 300 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. hive.metastore.batch.retrieve.table.partition.max 1000 Maximum number of table partitions that metastore internally retrieves in one batch. hive.default.fileformat TextFile Default file format for CREATE TABLE statement. Options are TextFile and SequenceFile. Users can explicitly say CREATE TABLE ... STORED AS <TEXTFILE|SEQUENCEFILE> to override hive.fileformat.check true Whether to check file format or not when loading data files hive.map.aggr true Whether to use map-side aggregation in Hive Group By queries hive.groupby.skewindata false Whether there is skew in data to optimize group by queries hive.optimize.multigroupby.common.distincts true 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 dont consider the fact that the distinct key is the same across different MR jobs. hive.groupby.mapaggr.checkinterval 100000 Number of rows after which size of the grouping keys/aggregation classes is performed hive.mapred.local.mem 0 For local mode, memory of the mappers/reducers hive.mapjoin.followby.map.aggr.hash.percentmemory 0.3 Portion of total memory to be used by map-side grup aggregation hash table, when this group by is followed by map join hive.map.aggr.hash.force.flush.memory.threshold 0.9 The max memory to be used by map-side grup aggregation hash table, if the memory usage is higher than this number, force to flush data hive.map.aggr.hash.percentmemory 0.5 Portion of total memory to be used by map-side grup aggregation hash table hive.map.aggr.hash.min.reduction 0.5 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. hive.optimize.cp true Whether to enable column pruner hive.optimize.index.filter false Whether to enable automatic use of indexes hive.optimize.index.groupby false Whether to enable optimization of group-by queries using Aggregate indexes. hive.optimize.ppd true Whether to enable predicate pushdown hive.optimize.ppd.storage true Whether to push predicates down into storage handlers. Ignored when hive.optimize.ppd is false. hive.ppd.recognizetransivity true Whether to transitively replicate predicate filters over equijoin conditions. hive.optimize.groupby true Whether to enable the bucketed group by from bucketed partitions/tables. hive.optimize.skewjoin.compiletime false 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 paramater 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. hive.optimize.union.remove false 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 aggresively. hive.mapred.supports.subdirectories false 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 hive.multigroupby.singlemr false 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. hive.map.groupby.sorted false 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. hive.map.groupby.sorted.testmode false 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. hive.new.job.grouping.set.cardinality 30 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 orginal group by will reduce the data size. hive.join.emit.interval 1000 How many rows in the right-most join operand Hive should buffer before emitting the join result. hive.join.cache.size 25000 How many rows in the joining tables (except the streaming table) should be cached in memory. hive.mapjoin.bucket.cache.size 100 How many values in each keys in the map-joined table should be cached in memory. hive.mapjoin.cache.numrows 25000 How many rows should be cached by jdbm for map join. hive.optimize.skewjoin false 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 a 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. hive.skewjoin.key 100000 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. hive.skewjoin.mapjoin.map.tasks 10000 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. hive.skewjoin.mapjoin.min.split 33554432 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. hive.mapred.mode nonstrict 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. hive.enforce.bucketmapjoin false If the user asked for bucketed map-side join, and it cannot be performed, should the query fail or not ? For eg, 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. hive.exec.script.maxerrsize 100000 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 hive.exec.script.allow.partial.consumption false When enabled, this option allows a user script to exit successfully without consuming all the data from the standard input. hive.script.operator.id.env.var HIVE_SCRIPT_OPERATOR_ID 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) hive.script.operator.truncate.env false Truncate each environment variable for external script in scripts operator to 20KB (to fit system limits) hive.exec.compress.output false 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* hive.exec.compress.intermediate false 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* hive.exec.parallel false Whether to execute jobs in parallel hive.exec.parallel.thread.number 8 How many jobs at most can be executed in parallel hive.exec.rowoffset false Whether to provide the row offset virtual column hive.task.progress false Whether Hive should periodically update task progress counters during execution. Enabling this allows task progress to be monitored more closely in the job tracker, but may impose a performance penalty. This flag is automatically set to true for jobs with hive.exec.dynamic.partition set to true. hive.hwi.war.file lib/hive-hwi-0.11.0.war This sets the path to the HWI war file, relative to ${HIVE_HOME}. hive.hwi.listen.host 0.0.0.0 This is the host address the Hive Web Interface will listen on hive.hwi.listen.port 9999 This is the port the Hive Web Interface will listen on hive.exec.pre.hooks 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. hive.exec.post.hooks 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. hive.exec.failure.hooks 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. hive.metastore.init.hooks A comma separated list of hooks to be invoked at the beginning of HMSHandler initialization. Aninit hook is specified as the name of Java class which extends org.apache.hadoop.hive.metastore.MetaStoreInitListener. hive.client.stats.publishers 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. hive.client.stats.counters 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 hive.merge.mapfiles true Merge small files at the end of a map-only job hive.merge.mapredfiles false Merge small files at the end of a map-reduce job hive.heartbeat.interval 1000 Send a heartbeat after this interval - used by mapjoin and filter operators hive.merge.size.per.task 256000000 Size of merged files at the end of the job hive.merge.smallfiles.avgsize 16000000 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. hive.mapjoin.smalltable.filesize 25000000 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 hive.ignore.mapjoin.hint true Ignore the mapjoin hint hive.mapjoin.localtask.max.memory.usage 0.90 This number means how much memory the local task can take to hold the key/value into in-memory hash table; If the local task's memory usage is more than this number, the local task will be abort by themself. It means the data of small table is too large to be hold in the memory. hive.mapjoin.followby.gby.localtask.max.memory.usage 0.55 This number means how much memory the local task can take to hold the key/value into in-memory hash table when this map join followed by a group by; If the local task's memory usage is more than this number, the local task will be abort by themself. It means the data of small table is too large to be hold in the memory. hive.mapjoin.check.memory.rows 100000 The number means after how many rows processed it needs to check the memory usage hive.auto.convert.join false Whether Hive enable the optimization about converting common join into mapjoin based on the input file size hive.auto.convert.join.noconditionaltask true Whether Hive enable the optimization about converting common join into mapjoin based on the input file size. If this paramater 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). hive.auto.convert.join.noconditionaltask.size 10000000 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 hive.optimize.mapjoin.mapreduce false If hive.auto.convert.join is off, this parameter does not take affect. If it is on, and if there are map-join jobs followed by a map-reduce job (for e.g a group by), each map-only job is merged with the following map-reduce job. hive.script.auto.progress false Whether Hive Tranform/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. hive.script.serde org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe The default serde for trasmitting input data to and reading output data from the user scripts. hive.binary.record.max.length 1000 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 hive.script.recordreader org.apache.hadoop.hive.ql.exec.TextRecordReader The default record reader for reading data from the user scripts. hive.script.recordwriter org.apache.hadoop.hive.ql.exec.TextRecordWriter The default record writer for writing data to the user scripts. hive.input.format org.apache.hadoop.hive.ql.io.CombineHiveInputFormat The default input format. Set this to HiveInputFormat if you encounter problems with CombineHiveInputFormat. hive.udtf.auto.progress false 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 infinte loops. hive.mapred.reduce.tasks.speculative.execution true Whether speculative execution for reducers should be turned on. hive.exec.counters.pull.interval 1000 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. hive.querylog.location /tmp/${user.name} Location of Hive run time structured log file hive.querylog.enable.plan.progress true 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 hive.querylog.plan.progress.interval 60000 The interval to wait between logging the plan's progress in milliseconds. 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. hive.enforce.bucketing false Whether bucketing is enforced. If true, while inserting into the table, bucketing is enforced. hive.enforce.sorting false Whether sorting is enforced. If true, while inserting into the table, sorting is enforced. hive.optimize.bucketingsorting true If hive.enforce.bucketing or hive.enforce.sorting is true, dont 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. hive.enforce.sortmergebucketmapjoin false If the user asked for sort-merge bucketed map-side join, and it cannot be performed, should the query fail or not ? hive.auto.convert.sortmerge.join false Will the join be automatically converted to a sort-merge join, if the joined tables pass the criteria for sort-merge join. hive.auto.convert.sortmerge.join.bigtable.selection.policy org.apache.hadoop.hive.ql.optimizer.AvgPartitionSizeBasedBigTableSelectorForAutoSMJ 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. hive.metastore.ds.connection.url.hook Name of the hook to use for retriving the JDO connection URL. If empty, the value in javax.jdo.option.ConnectionURL is used hive.metastore.ds.retry.attempts 1 The number of times to retry a metastore call if there were a connection error hive.metastore.ds.retry.interval 1000 The number of miliseconds between metastore retry attempts hive.metastore.server.min.threads 200 Minimum number of worker threads in the Thrift server's pool. hive.metastore.server.max.threads 100000 Maximum number of worker threads in the Thrift server's pool. hive.metastore.server.tcp.keepalive true Whether to enable TCP keepalive for the metastore server. Keepalive will prevent accumulation of half-open connections. hive.metastore.sasl.enabled false If true, the metastore thrift interface will be secured with SASL. Clients must authenticate with Kerberos. hive.metastore.thrift.framed.transport.enabled false If true, the metastore thrift interface will use TFramedTransport. When false (default) a standard TTransport is used. hive.metastore.kerberos.keytab.file The path to the Kerberos Keytab file containing the metastore thrift server's service principal. hive.metastore.kerberos.principal hive-metastore/_HOST@EXAMPLE.COM The service principal for the metastore thrift server. The special string _HOST will be replaced automatically with the correct host name. hive.cluster.delegation.token.store.class org.apache.hadoop.hive.thrift.MemoryTokenStore The delegation token store implementation. Set to org.apache.hadoop.hive.thrift.ZooKeeperTokenStore for load-balanced cluster. hive.cluster.delegation.token.store.zookeeper.connectString localhost:2181 The ZooKeeper token store connect string. hive.cluster.delegation.token.store.zookeeper.znode /hive/cluster/delegation The root path for token store data. hive.cluster.delegation.token.store.zookeeper.acl sasl:hive/host1@EXAMPLE.COM:cdrwa,sasl:hive/host2@EXAMPLE.COM:cdrwa ACL for token store entries. List comma separated all server principals for the cluster. hive.metastore.cache.pinobjtypes Table,StorageDescriptor,SerDeInfo,Partition,Database,Type,FieldSchema,Order List of comma separated metastore object types that should be pinned in the cache hive.optimize.reducededuplication true 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. hive.optimize.reducededuplication.min.reducer 4 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 disabled if number of reducers is less than specified value. hive.exec.dynamic.partition true Whether or not to allow dynamic partitions in DML/DDL. hive.exec.dynamic.partition.mode strict In strict mode, the user must specify at least one static partition in case the user accidentally overwrites all partitions. hive.exec.max.dynamic.partitions 1000 Maximum number of dynamic partitions allowed to be created in total. hive.exec.max.dynamic.partitions.pernode 100 Maximum number of dynamic partitions allowed to be created in each mapper/reducer node. hive.exec.max.created.files 100000 Maximum number of HDFS files created by all mappers/reducers in a MapReduce job. hive.exec.default.partition.name __HIVE_DEFAULT_PARTITION__ The default partition name in case the dynamic partition column value is null/empty string or anyother 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. hive.stats.dbclass jdbc:derby The default database that stores temporary hive statistics. hive.stats.autogather true A flag to gather statistics automatically during the INSERT OVERWRITE command. hive.stats.jdbcdriver org.apache.derby.jdbc.EmbeddedDriver The JDBC driver for the database that stores temporary hive statistics. hive.stats.dbconnectionstring jdbc:derby:;databaseName=TempStatsStore;create=true The default connection string for the database that stores temporary hive statistics. hive.stats.default.publisher The Java class (implementing the StatsPublisher interface) that is used by default if hive.stats.dbclass is not JDBC or HBase. hive.stats.default.aggregator The Java class (implementing the StatsAggregator interface) that is used by default if hive.stats.dbclass is not JDBC or HBase. hive.stats.jdbc.timeout 30 Timeout value (number of seconds) used by JDBC connection and statements. hive.stats.retries.max 0 Maximum number of retries when stats publisher/aggregator got an exception updating intermediate database. Default is no tries on failures. hive.stats.retries.wait 3000 The base waiting window (in milliseconds) before the next retry. The actual wait time is calculated by baseWindow * failues baseWindow * (failure 1) * (random number between [0.0,1.0]). hive.stats.reliable false 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 becuase the stats could not be computed accurately. hive.stats.collect.tablekeys false 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. hive.stats.collect.scancols false 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. hive.stats.ndv.error 20.0 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. hive.stats.key.prefix.max.length 200 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 is never used, if the value >= 0 then hashing is used only when the key prefixes length exceeds that value. The key prefix is defined as everything preceding the task ID in the key. hive.support.concurrency false Whether hive supports concurrency or not. A zookeeper instance must be up and running for the default hive lock manager to support read-write locks. hive.lock.numretries 100 The number of times you want to try to get all the locks hive.unlock.numretries 10 The number of times you want to retry to do one unlock hive.lock.sleep.between.retries 60 The sleep time (in seconds) between various retries hive.zookeeper.quorum The list of zookeeper servers to talk to. This is only needed for read/write locks. hive.zookeeper.client.port 2181 The port of zookeeper servers to talk to. This is only needed for read/write locks. hive.zookeeper.session.timeout 600000 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. hive.zookeeper.namespace hive_zookeeper_namespace The parent node under which all zookeeper nodes are created. hive.zookeeper.clean.extra.nodes false Clean extra nodes at the end of the session. fs.har.impl org.apache.hadoop.hive.shims.HiveHarFileSystem The implementation for accessing Hadoop Archives. Note that this won't be applicable to Hadoop vers less than 0.20 hive.archive.enabled false Whether archiving operations are permitted hive.fetch.output.serde org.apache.hadoop.hive.serde2.DelimitedJSONSerDe The serde used by FetchTask to serialize the fetch output. hive.exec.mode.local.auto false Let hive determine whether to run in local mode automatically hive.exec.drop.ignorenonexistent true Do not report an error if DROP TABLE/VIEW specifies a non-existent table/view hive.exec.show.job.failure.debug.info true 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. hive.auto.progress.timeout 0 How long to run autoprogressor for the script/UDTF operators (in seconds). Set to 0 for forever. hive.hbase.wal.enabled true 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. hive.table.parameters.default Default property values for newly created tables hive.entity.separator @ Separator used to construct names of tables and partitions. For example, dbname@tablename@partitionname hive.ddl.createtablelike.properties.whitelist Table Properties to copy over when executing a Create Table Like. hive.variable.substitute true This enables substitution using syntax like ${var} ${system:var} and ${env:var}. hive.variable.substitute.depth 40 The maximum replacements the substitution engine will do. hive.conf.validation true Eables type checking for registered hive configurations hive.security.authorization.enabled false enable or disable the hive client authorization hive.security.authorization.manager org.apache.hadoop.hive.ql.security.authorization.DefaultHiveAuthorizationProvider the hive client authorization manager class name. The user defined authorization class should implement interface org.apache.hadoop.hive.ql.security.authorization.HiveAuthorizationProvider. hive.security.metastore.authorization.manager org.apache.hadoop.hive.ql.security.authorization.DefaultHiveMetastoreAuthorizationProvider authorization manager class name to be used in the metastore for authorization. The user defined authorization class should implement interface org.apache.hadoop.hive.ql.security.authorization.HiveMetastoreAuthorizationProvider. hive.security.authenticator.manager org.apache.hadoop.hive.ql.security.HadoopDefaultAuthenticator hive client authenticator manager class name. The user defined authenticator should implement interface org.apache.hadoop.hive.ql.security.HiveAuthenticationProvider. hive.security.metastore.authenticator.manager org.apache.hadoop.hive.ql.security.HadoopDefaultMetastoreAuthenticator 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. hive.security.authorization.createtable.user.grants 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. hive.security.authorization.createtable.group.grants 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. hive.security.authorization.createtable.role.grants 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. hive.security.authorization.createtable.owner.grants 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 hive.metastore.authorization.storage.checks false Should the metastore do authorization checks against the underlying storage 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). hive.error.on.empty.partition false Whether to throw an excpetion if dynamic partition insert generates empty results. hive.index.compact.file.ignore.hdfs false True the hdfs location stored in the index file will be igbored at runtime. If the data got moved or the name of the cluster got changed, the index data should still be usable. hive.optimize.index.filter.compact.minsize 5368709120 Minimum size (in bytes) of the inputs on which a compact index is automatically used. hive.optimize.index.filter.compact.maxsize -1 Maximum size (in bytes) of the inputs on which a compact index is automatically used. A negative number is equivalent to infinity. hive.index.compact.query.max.size 10737418240 The maximum number of bytes that a query using the compact index can read. Negative value is equivalent to infinity. hive.index.compact.query.max.entries 10000000 The maximum number of index entries to read during a query that uses the compact index. Negative value is equivalent to infinity. hive.index.compact.binary.search true Whether or not to use a binary search to find the entries in an index table that match the filter, where possible hive.exim.uri.scheme.whitelist hdfs,pfile A comma separated list of acceptable URI schemes for import and export. hive.lock.mapred.only.operation false This param is to control whether or not only do lock on queries that need to execute at least one mapred job. hive.limit.row.max.size 100000 When trying a smaller subset of data for simple LIMIT, how much size we need to guarantee each row to have at least. hive.limit.optimize.limit.file 10 When trying a smaller subset of data for simple LIMIT, maximum number of files we can sample. hive.limit.optimize.enable false Whether to enable to optimization to trying a smaller subset of data for simple LIMIT first. hive.limit.optimize.fetch.max 50000 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. hive.rework.mapredwork false should rework the mapred work or not. This is first introduced by SymlinkTextInputFormat to replace symlink files with real paths at compile time. hive.exec.concatenate.check.index true If this sets 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. hive.sample.seednumber 0 A number used to percentage sampling. By changing this number, user will change the subsets of data sampled. hive.io.exception.handlers A list of io exception handler class names. This is used to construct a list exception handlers to handle exceptions thrown by record readers hive.autogen.columnalias.prefix.label _c 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. hive.autogen.columnalias.prefix.includefuncname false Whether to include function name in the column alias auto generated by hive. hive.exec.perf.logger org.apache.hadoop.hive.ql.log.PerfLogger The class responsible logging client side performance metrics. Must be a subclass of org.apache.hadoop.hive.ql.log.PerfLogger hive.start.cleanup.scratchdir false To cleanup the hive scratchdir while starting the hive server hive.output.file.extension 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. hive.insert.into.multilevel.dirs false Where to insert into multilevel directories like "insert directory '/HIVEFT25686/chinna/' from table" hive.warehouse.subdir.inherit.perms false 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 hive.exec.job.debug.capture.stacktraces true 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 hive.exec.driver.run.hooks A comma separated list of hooks which implement HiveDriverRunHook and will be run at the beginning and end of Driver.run, these will be run in the order specified hive.ddl.output.format text The data format to use for DDL output. One of "text" (for human readable text) or "json" (for a json object). hive.transform.escape.input false 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. hive.exec.rcfile.use.explicit.header true If this is set the header for RC Files 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 RC File formats. hive.multi.insert.move.tasks.share.dependencies false 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. hive.fetch.task.conversion minimal 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 incurrs RS), lateral views and joins. 1. minimal : SELECT STAR, FILTER on partition columns, LIMIT only 2. more : SELECT, FILTER, LIMIT only (TABLESAMPLE, virtual columns) hive.hmshandler.retry.attempts 1 The number of times to retry a HMSHandler call if there were a connection error hive.hmshandler.retry.interval 1000 The number of miliseconds between HMSHandler retry attempts hive.server.read.socket.timeout 10 Timeout for the HiveServer to close the connection if no response from the client in N seconds, defaults to 10 seconds. hive.server.tcp.keepalive true Whether to enable TCP keepalive for the Hive server. Keepalive will prevent accumulation of half-open connections. hive.decode.partition.name false Whether to show the unquoted partition names in query results. hive.log4j.file 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). hive.exec.log4j.file 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). hive.exec.infer.bucket.sort false 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) hive.exec.infer.bucket.sort.num.buckets.power.two false 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. hive.groupby.orderby.position.alias false Whether to enable using Column Position Alias in Group By or Order By hive.server2.thrift.min.worker.threads 5 Minimum number of Thrift worker threads hive.server2.thrift.max.worker.threads 100 Maximum number of Thrift worker threads hive.server2.thrift.port 10000 Port number of HiveServer2 Thrift interface. Can be overridden by setting $HIVE_SERVER2_THRIFT_PORT hive.server2.thrift.bind.host localhost Bind host on which to run the HiveServer2 Thrift interface. Can be overridden by setting $HIVE_SERVER2_THRIFT_BIND_HOST hive.server2.authentication NONE 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) hive.server2.custom.authentication.class 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 extend the Hadoop's org.apache.hadoop.conf.Configured class to grab Hive's Configuration object. >hive.server2.authentication.kerberos.principal Kerberos server principal >hive.server2.authentication.kerberos.keytab Kerberos keytab file for server principal hive.server2.authentication.ldap.url LDAP connection URL hive.server2.authentication.ldap.baseDN LDAP base DN hive.server2.enable.doAs true Setting this property to true will have hive server2 execute hive operations as the user making the calls to it.