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, don't sample the above comma separated list of tables
hive.metastore.uris
thrift://dataweb01:9083,thrift://dataweb02:9083
Thrift URI for the remote metastore. Used by metastore client to connect to remote metastore.
javax.jdo.option.ConnectionURL
jdbc:mysql://rm-m5e842126ng59jrv6.mysql.rds.aliyuncs.com:3306/hive
JDBC connect string for a JDBC metastore
javax.jdo.option.ConnectionDriverName
com.mysql.jdbc.Driver
Driver class name for a JDBC metastore
javax.jdo.PersistenceManagerFactoryClass
org.datanucleus.api.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
hive_xmtnrifc2c
username to use against metastore database
javax.jdo.option.ConnectionPassword
6185caxgEzevuykFbystrhiI56968q20
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
BoneCP
Uses a BoneCP 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
datanucleus1
Name of the identifier factory to use when generating table/column names etc. 'datanucleus1' is used for backward compatibility with DataNucleus v1
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 separated listeners for metastore events.
hive.metastore.partition.inherit.table.properties
list of comma separated 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.disallow.incompatible.col.type.change
If true (default is false), ALTER TABLE operations which change the type of
a column (say STRING) to an incompatible type (say MAP<STRING, STRING>) 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.
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.default.rcfile.serde
org.apache.hadoop.hive.serde2.columnar.LazyBinaryColumnarSerDe
The default SerDe Hive will use for the RCFile format
hive.fileformat.check
true
Whether to check file format or not when loading data files
hive.file.max.footer
100
maximum number of lines for footer user can define for a table file
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 don't 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
mapred.input.dir.recursive
true
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 group 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 group 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 group aggregation hash table
hive.session.history.enabled
false
Whether to log Hive query, query plan, runtime statistics etc.
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.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.sort.dynamic.partition
true
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.
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 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.
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 aggressively.
hive.mapred.supports.subdirectories
true
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.singlereducer
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 original 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.smbjoin.cache.rows
10000
How many rows with the same key value should be cached in memory per SMB joined table.
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 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.
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
strict
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 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.
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.counters.group.name
HIVE
The name of counter group for internal Hive variables (CREATED_FILE, FATAL_ERROR, etc.)
hive.hwi.war.file
lib/hive-hwi-@VERSION@.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. An init 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.merge.tezfiles
false
Merge small files at the end of a Tez DAG
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 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.
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 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.
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
true
Whether Hive enables the optimization about converting common join into mapjoin based on the input file size
hive.auto.convert.join.noconditionaltask
true
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).
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.auto.convert.join.use.nonstaged
false
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.
hive.script.auto.progress
false
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.
hive.script.serde
org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe
The default SerDe for transmitting 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.server2.max.start.attempts
30
This 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.
hive.server2.transport.mode
binary
Server transport mode. "binary" or "http".
hive.server2.thrift.http.port
10001
Port number when in HTTP mode.
hive.server2.thrift.http.path
cliservice
Path component of URL endpoint when in HTTP mode.
hive.server2.thrift.http.min.worker.threads
5
Minimum number of worker threads when in HTTP mode.
hive.server2.thrift.http.max.worker.threads
500
Maximum number of worker threads when in HTTP mode.
hive.script.recordreader
org.apache.hadoop.hive.ql.exec.TextRecordReader
The default record reader for reading data from the user scripts.
stream.stderr.reporter.prefix
reporter:
Streaming jobs that log to standard error with this prefix can log counter or status information.
stream.stderr.reporter.enabled
true
Enable consumption of status and counter messages for streaming jobs.
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.tez.input.format
org.apache.hadoop.hive.ql.io.HiveInputFormat
The default input format for tez. Tez groups splits in the AM.
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 infinite 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, 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.
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.auto.convert.sortmerge.join.to.mapjoin
false
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.
hive.metastore.ds.connection.url.hook
Name of the hook to use for retrieving 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 milliseconds 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.correlation
false
exploit intra-query correlations.
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
nonstrict
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 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.
hive.stats.dbclass
fs
The storage that stores temporary Hive statistics. Supported values are
fs (filesystem), jdbc(:.*), hbase, counter, and custom. In FS based statistics collection,
each task writes statistics it has collected in a file on the filesystem, which will be
aggregated after the job has finished.
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 custom type.
hive.stats.default.aggregator
The Java class (implementing the StatsAggregator interface) that is used by default if hive.stats.dbclass is custom type.
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 * failures 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 because 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.
For counter type stats, it's maxed by mapreduce.job.counters.group.name.max, which is by default 128.
hive.stats.key.prefix.reserve.length
24
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.
hive.stats.max.variable.length
100
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.).
hive.stats.list.num.entries
10
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.
hive.stats.map.num.entries
10
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.
hive.stats.map.parallelism
1
Hive/Tez optimizer estimates the data size flowing through each of the operators.
For GROUPBY operator, to accurately compute the data size map-side parallelism needs to
be known. By default, this value is set to 1 since optimizer is not aware of the number of
mappers during compile-time. This Hive config can be used to specify the number of mappers
to be used for data size computation of GROUPBY operator.
hive.stats.fetch.column.stats
false
Annotation of operator tree with statistics information requires column statisitcs.
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.
hive.stats.fetch.partition.stats
true
Annotation of operator tree with statistics information requires partition level basic
statisitcs 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.
hive.stats.join.factor
1.1
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.
hive.stats.deserialization.factor
1.0
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.
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
zk-kafka01:2181,zk-kafka02:2181,zk-kafka03:2181
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 versions 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
Enables 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.plugin.sqlstd.SQLStdHiveAuthorizerFactory
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.SessionStateUserAuthenticator
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.users.in.admin.role
hadoop
Comma separated list of users who are in admin role for bootstrapping.
More users can be added in ADMIN role later.
hive.security.command.whitelist
set,reset,dfs,add,delete
Comma separated list of non-SQL Hive commands users are authorized to execute
hive.conf.restricted.list
hive.security.authenticator.manager,hive.security.authorization.manager,hive.users.in.admin.role
Comma separated list of configuration options which are immutable at runtime
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 exception if dynamic partition insert generates empty results.
hive.index.compact.file.ignore.hdfs
false
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.
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.limit.pushdown.memory.usage
0.3f
The max memory to be used for hash in RS operator for top K selection.
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 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.
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.display.partition.cols.separately
true
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.
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 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.
hive.exec.orc.default.stripe.size
268435456
Define the default ORC stripe size.
hive.exec.orc.default.row.index.stride
10000
Define the default ORC index stride in number of rows.
hive.exec.orc.default.buffer.size
262144
Define the default ORC buffer size in bytes.
hive.exec.orc.default.block.padding
true
Define the default block padding.
hive.exec.orc.default.compress
ZLIB
Define the default compression codec for ORC file.
hive.exec.orc.dictionary.key.size.threshold
0.8
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.
hive.exec.orc.skip.corrupt.data
false
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.
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 incurs 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.fetch.task.conversion.threshold
-1
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.
hive.fetch.task.aggr
false
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.
hive.cache.expr.evaluation
true
If true, evaluation result of deterministic expression referenced twice or more will be cached.
For example, in filter condition like ".. where key + 10 > 10 or key + 10 = 0"
"key + 10" will be evaluated/cached once and reused for following expression ("key + 10 = 0").
Currently, this is applied only to expressions in select or filter operator.
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 milliseconds 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
500
Maximum number of Thrift worker threads
hive.server2.async.exec.threads
100
Number of threads in the async thread pool for HiveServer2
hive.server2.async.exec.shutdown.timeout
10
Time (in seconds) for which HiveServer2 shutdown will wait for async
threads to terminate
hive.server2.async.exec.keepalive.time
10
Time (in seconds) that an idle HiveServer2 async thread (from the thread pool) will wait
for a new task to arrive before terminating
hive.server2.long.polling.timeout
5000L
Time in milliseconds that HiveServer2 will wait, before responding to asynchronous calls that use long polling
hive.server2.async.exec.wait.queue.size
100
Size of the wait queue for async thread pool in HiveServer2.
After hitting this limit, the async thread pool will reject new requests.
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
datacenter05
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)
PAM: Pluggable authentication module.
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 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.spnego.principal
SPNego service principal, optional,
typical value would look like HTTP/_HOST@EXAMPLE.COM
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.
hive.server2.authentication.spnego.keytab
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.
hive.server2.authentication.ldap.url
LDAP connection URL.
hive.server2.authentication.ldap.baseDN
LDAP base DN (distinguished name).
hive.server2.authentication.ldap.Domain
LDAP domain.
hive.server2.enable.doAs
true
Setting this property to true will have HiveServer2 execute
Hive operations as the user making the calls to it.
hive.execution.engine
mr
Chooses execution engine. Options are mr (MapReduce, default) or Tez (Hadoop 2 only).
hive.prewarm.enabled
false
Enables container prewarm for Tez (Hadoop 2 only).
hive.prewarm.numcontainers
10
Controls the number of containers to prewarm for Tez (Hadoop 2 only).
hive.server2.table.type.mapping
CLASSIC
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
hive.server2.session.hook
Session-level hook for HiveServer2.
hive.server2.thrift.sasl.qop
auth
Sasl QOP value; set it to one of the following values to enable higher levels of
protection for HiveServer2 communication with clients.
"auth" - authentication only (default)
"auth-int" - authentication plus integrity protection
"auth-conf" - authentication plus integrity and confidentiality protection
Note that hadoop.rpc.protection being set 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.
This is applicable only if HiveServer2 is configured to use Kerberos authentication.
hive.plan.serialization.format
kryo
Query plan format serialization between client and task nodes.
Two supported values are : kryo and javaXML. Kryo is default.
hive.vectorized.execution.enabled
false
This flag should be set to true to enable vectorized mode of query execution.
The default value is false.
hive.vectorized.groupby.maxentries
1000000
Max number of entries in the vector group by aggregation hashtables. Exceeding this will trigger a flush irrelevant of memory pressure condition.
hive.vectorized.groupby.checkinterval
100000
Number of entries added to the group by aggregation hash before a reocmputation of average entry size is performed.
hive.vectorized.groupby.flush.percent
0.1
Percent of entries in the group by aggregation hash flushed when the memory treshold is exceeded.
hive.compute.query.using.stats
false
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.
hive.metastore.schema.verification
false
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.
hive.metastore.integral.jdo.pushdown
false
Allow JDO query pushdown for integral partition columns in the metastore. Off by default.
This improves metastore performance for integral columns, especially with a large number of
partitions. However, it doesn't work correctly for integral values that are not normalized
(for example, if they have leading zeroes like 0012). If metastore direct SQL is enabled and
works (hive.metastore.try.direct.sql), this optimization is also irrelevant.
hive.orc.splits.include.file.footer
false
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.
hive.orc.cache.stripe.details.size
10000
Cache size for keeping meta info about orc splits cached in the client.
hive.orc.compute.splits.num.threads
10
How many threads orc should use to create splits in parallel.
hive.stats.gather.num.threads
10
Number of threads used by partialscan/noscan analyze command for partitioned tables.
This is applicable only for file formats that implement StatsProvidingRecordReader (like ORC).
hive.exec.orc.zerocopy.
false
Use zerocopy reads with ORC.
hive.jar.directory
This is the location Hive in Tez mode will look for to find a site wide
installed Hive instance. If not set, the directory under hive.user.install.directory
corresponding to current user name will be used.
hive.user.install.directory
hdfs:///user/
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.
hive.tez.container.size
-1
By default Tez will spawn containers of the size of a mapper. This can be used to overwrite.
hive.tez.java.opts
By default Tez will use the Java options from map tasks. This can be used to overwrite.
hive.tez.log.level
INFO
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.
hive.server2.tez.default.queues
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.
hive.server2.tez.sessions.per.default.queue
1
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.
hive.server2.tez.initialize.default.sessions
false
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.
hive.server2.allow.user.substitution
true
Allow alternate user to be specified as part of HiveServer2 open connection request
hive.resultset.use.unique.column.names
true
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..".
hive.compat
0.12
Enable (configurable) deprecated behaviors by setting desired level of backward compatbility
hive.metastore.try.direct.sql
true
Whether Hive metastore should try to use direct SQL queries instead of DataNucleus for certain
read paths. Can improve metastore performance when fetching many partitions or column stats by
orders of magnitude; however, is not guaranteed to work on all RDBMS-es and all versions. In case
of SQL failures, metastore will fall back to DataNucleus, so it's safe even if SQL doesn't work
for all queries on your datastore. If all SQL queries fail (e.g. your metastore is backed by
MongoDB), you might want to disable this to save the try-and-fall-back cost.
hive.metastore.try.direct.sql.ddl
true
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 direct SQL select query has
incorrect syntax or something inside a transaction, 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.
hive.mapjoin.optimized.keys
true
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.
hive.mapjoin.lazy.hashtable
true
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.
hive.exec.check.crossproducts
true
Check if a plan contains a Cross Product. If there is one, output a warning to the Session's console.
hive.localize.resource.wait.interval
5000
Time in milliseconds to wait for another thread to localize the same resource for hive-tez.
hive.localize.resource.num.wait.attempts
5
The number of attempts waiting for localizing a resource in hive-tez.
hive.server2.use.SSL
false
Set this to true for using SSL encryption in HiveServer2
hive.server2.keystore.path
SSL certificate keystore location
hive.server2.keystore.password
SSL certificate keystore password.
hive.server2.authentication.pam.services
List of the underlying PAM services that should be used when authentication
type is PAM (hive.server2.authentication). A file with the same name must exist in
/etc/pam.d
hive.convert.join.bucket.mapjoin.tez
false
Whether joins can be automatically converted to bucket map
joins in hive when tez is used as the execution engine.
hive.serdes.using.metastore.for.schema
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
This an internal parameter. Check with the hive dev. team
hive.limit.query.max.table.partition
-1
This controls how many partitions can be scanned for each partitioned table. The default value "-1" means no limit.
hive.txn.manager
org.apache.hadoop.hive.ql.lockmgr.DummyTxnManager
hive.txn.timeout
300
time after which transactions are declared aborted if the client has
not sent a heartbeat, in seconds.
hive.txn.max.open.batch
1000
Maximum number of transactions that can be fetched in one call to open_txns().
Increasing this will decrease the number of delta files created when
streaming data into Hive. But it will also increase the number of
open transactions at any given time, possibly impacting read
performance.
hive.compactor.initiator.on
false
Whether to run the compactor's initiator thread in this metastore instance or not.
hive.compactor.worker.threads
0
Number of compactor worker threads to run on this metastore instance.
hive.compactor.worker.timeout
86400
Time, in seconds, before a given compaction in working state is declared a failure and returned to the initiated state.
hive.compactor.check.interval
300
Time in seconds between checks to see if any partitions need compacted.
This should be kept high because each check for compaction requires many calls against the NameNode.
hive.compactor.delta.num.threshold
10
Number of delta files that must exist in a directory before the compactor will attempt a minor compaction.
hive.compactor.delta.pct.threshold
0.1
Percentage (by size) of base that deltas can be before major compaction is initiated.
hive.compactor.abortedtxn.threshold
1000
Number of aborted transactions involving a particular table or partition before major compaction is initiated.
hive.server2.support.dynamic.service.discovery
false
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.
hive.server2.zookeeper.namespace
hiveserver2
The parent node in ZooKeeper used by HiveServer2 when supporting dynamic service discovery.
hive.security.authorization.sqlstd.confwhitelist.append
oozie.*|hive.server2.proxy.user|mapreduce.job.name|mapreduce.job.reduce.parallelism.num|mapreduce.am.max-attempts|mapreduce.job.running.map.limit|mapreduce.job.running.reduce.limit|mapreduce.job.*|mapred.input.dir.recursive|mapreduce.job.*|dfs.*|mapred.output.compression.type|hive.metastore.uris|hbase.zookeeper.quorum|zookeeper.znode.parent
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.
hive.security.authorization.task.factory
org.apache.hadoop.hive.ql.parse.authorization.HiveAuthorizationTaskFactoryImpl
phoenix.schema.isNamespaceMappingEnabled
true
phoenix.schema.mapSystemTablesToNamespace
true