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Hive Variable | Set Hive Variable | HiveConf,Hivevar in hive
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Hive Variable for Hive Scripts
Hive stores variables in four different namespaces, namespace is a way to separate variables.
- hiveconf
- hivevar
- system, and
- env.
hiveconf
select region ,city from temperature where region='Africa' and city='Lusaka' limit 10;
set regionname;
regionname='Africa'
set cityname;
cityname='Lusaka'
set table;
table=temperature
select region ,city from ${hiveconf:table} where region=${hiveconf:regionname} and city=${hiveconf:cityname} limit 10;
hivevar
SET hivevar:table=temperature;
select * from ${hivevar:table} limit 10;
or
SELECT * FROM ${table}
Hive Environment Variables (env)
SELECT "${env:HIVE_HOME}";
OK
/home/hdoop/apache-hive-3.1.1-bin
Time taken: 2.469 seconds, Fetched: 1 row(s)
Hive System Variables (system)
SELECT "${system:user.name}";
OK
hdoop
Time taken: 0.193 seconds, Fetched: 1 row(s)
Set hive command line variable
hdoop@hadoop:~$ hive --hivevar table=temperature
hive>
> select * from bucket.${table} limit 10;
OK
Zambia Lusaka 1 1 1995 73 Africa
Zambia Lusaka 1 2 1995 70 Africa
Zambia Lusaka 1 3 1995 72 Africa
Zambia Lusaka 1 4 1995 76 Africa
Zambia Lusaka 1 5 1995 76 Africa
Zambia Lusaka 1 6 1995 74 Africa
Zambia Lusaka 1 7 1995 76 Africa
Zambia Lusaka 1 8 1995 78 Africa
Zambia Lusaka 1 9 1995 77 Africa
Zambia Lusaka 1 10 1995 77 Africa
Time taken: 1.998 seconds, Fetched: 10 row(s)
Pass variable to hive script
hdoop@hadoop:~$ hive --hivevar table=temperature -f demo.hql Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Africa Lusaka Time taken: 2.955 seconds, Fetched: 10 row(s)
hql scripts
hdoop@hadoop:~$ cat demo.hql
set regionname='Africa';
set cityname='Lusaka';
use bucket;
select region ,city from ${table} where region=${hiveconf:regionname} and city=${hiveconf:cityname} limit 10;