THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Hive CLI
$HIVE_HOME/bin/hive is a shell utility which can be used to run Hive queries in either interactive or batch mode.
Hive Command Line Options
To get help, run "hive -H" or "hive --help".
Usage (as it is in Hive 0.9.0):
usage: hive
-d,--define <key=value> Variable substitution to apply to hive
commands. e.g. -d A=B or --define A=B
-e <quoted-query-string> SQL from command line
-f <filename> SQL from files
-H,--help Print help information
-h <hostname> Connecting to Hive Server on remote host
--hiveconf <property=value> Use value for given property
--hivevar <key=value> Variable substitution to apply to hive
commands. e.g. --hivevar A=B
-i <filename> Initialization SQL file
-p <port> Connecting to Hive Server on port number
-S,--silent Silent mode in interactive shell
-v,--verbose Verbose mode (echo executed SQL to the
console)
See Variable Substitution for examples of using the hiveconf option.
Version information
As of Hive 0.10.0 there is one additional command line option:
--database <dbname> Specify the database to use
- Example of running a query from the command line
$HIVE_HOME/bin/hive -e 'select a.col from tab1 a'
- Example of setting Hive configuration variables
$HIVE_HOME/bin/hive -e 'select a.col from tab1 a' -hiveconf hive.exec.scratchdir=/home/my/hive_scratch -hiveconf mapred.reduce.tasks=32
- Example of dumping data out from a query into a file using silent mode
$HIVE_HOME/bin/hive -S -e 'select a.col from tab1 a' > a.txt
- Example of running a script non-interactively
$HIVE_HOME/bin/hive -f /home/my/hive-script.sql
- Example of running an initialization script before entering interactive mode
$HIVE_HOME/bin/hive -i /home/my/hive-init.sql
The hiverc File
The CLI when invoked without the -i option will attempt to load $HIVE_HOME/bin/.hiverc and $HOME/.hiverc as initialization files.
Hive Batch Mode Commands
When $HIVE_HOME/bin/hive is run with the -e or -f option, it executes SQL commands in batch mode.
hive -e '<query-string>'executes the query string.hive -f <filepath>executes one or more SQL queries from a file.
Examples are shown above.
Hive Interactive Shell Commands
When $HIVE_HOME/bin/hive is run without either the -e or -f option, it enters interactive shell mode.
Use ";" (semicolon) to terminate commands. Comments in scripts can be specified using the "--" prefix.
Command |
Description |
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|---|---|---|---|
quit |
Use quit or exit to leave the interactive shell. |
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reset |
Resets the configuration to the default values (as of Hive 0.10: see HIVE-3202). |
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set <key>=<value> |
Sets the value of a particular configuration variable (key). |
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set |
Prints a list of configuration variables that are overridden by the user or Hive. |
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set -v |
Prints all Hadoop and Hive configuration variables. |
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add FILE[S] <filepath> <filepath>* |
Adds one or more files, jars, or archives to the list of resources in the distributed cache. |
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list FILE[S] |
Lists the resources already added to the distributed cache. |
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list FILE[S] <filepath>* |
Checks whether the given resources are already added to the distributed cache or not. |
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delete FILE[S] <filepath>* |
Removes the resource(s) from the distributed cache. |
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! <command> |
Executes a shell command from the Hive shell. |
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dfs <dfs command> |
Executes a dfs command from the Hive shell. |
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<query string> |
Executes a Hive query and prints results to standard output. |
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source FILE <filepath> |
Executes a script file inside the CLI. |
Sample Usage:
hive> set mapred.reduce.tasks=32; hive> set; hive> select a.* from tab1; hive> !ls; hive> dfs -ls;
Logging
Hive uses log4j for logging. These logs are not emitted to the standard output by default but are instead captured to a log file specified by Hive's log4j properties file. By default Hive will use hive-log4j.default in the conf/ directory of the Hive installation which writes out logs to /tmp/<userid>/hive.log and uses the WARN level.
It is often desirable to emit the logs to the standard output and/or change the logging level for debugging purposes. These can be done from the command line as follows:
$HIVE_HOME/bin/hive -hiveconf hive.root.logger=INFO,console
hive.root.logger specifies the logging level as well as the log destination. Specifying console as the target sends the logs to the standard error (instead of the log file).
Hive Resources
Hive can manage the addition of resources to a session where those resources need to be made available at query execution time. The resources can be files, jars, or archives. Any locally accessible file can be added to the session.
Once a resource is added to a session, Hive queries can refer to it by its name (in map/reduce/transform clauses) and the resource is available locally at execution time on the entire Hadoop cluster. Hive uses Hadoop's Distributed Cache to distribute the added resources to all the machines in the cluster at query execution time.
Usage:
ADD { FILE[S] | JAR[S] | ARCHIVE[S] } <filepath1> [<filepath2>]*
LIST { FILE[S] | JAR[S] | ARCHIVE[S] } [<filepath1> <filepath2> ..]
DELETE { FILE[S] | JAR[S] | ARCHIVE[S] } [<filepath1> <filepath2> ..]
- FILE resources are just added to the distributed cache. Typically, this might be something like a transform script to be executed.
- JAR resources are also added to the Java classpath. This is required in order to reference objects they contain such as UDFs.
- ARCHIVE resources are automatically unarchived as part of distributing them.
Example:
hive> add FILE /tmp/tt.py;
hive> list FILES;
/tmp/tt.py
hive> select from networks a
MAP a.networkid
USING 'python tt.py' as nn where a.ds = '2009-01-04' limit 10;
It is not neccessary to add files to the session if the files used in a transform script are already available on all machines in the Hadoop cluster using the same path name. For example:
... MAP a.networkid USING 'wc -l' ...
Herewcis an executable available on all machines.... MAP a.networkid USING '/home/nfsserv1/hadoopscripts/tt.py' ...
Herett.pymay be accessible via an NFS mount point that's configured identically on all the cluster nodes.