CODEWITHSUNDEEP
hivehortonworks-data-platformudf
wergeld
wergeld

Reputation: 14462

How To Add A JAR To Hive

I have been banging my head against the wall for a while now on how to get a hive equivalent of MS SQL's IDENTITY column added to a table and auto incremented. I have found many references to org.apache.hadoop.hive.contrib.udf.UDFRowSequence but I have no idea where that is in my HortonWorks 2.3 install of my cluster. I have no idea where to start on this. I have seen an java file here which I assume I have to compile but once I have a .jar where does it go? I have tried using a SerDe jar for another task and I could never get hive to see/use it (see my question on this here). I have tried to follow along with this case study on creating a custom UDF here. However, I can find no path like they are describing in my Hortonworks install (the path looks something like ql/src/java/org/apache/hadoop/hive/ql/udf/generic/).

It seems like each tutorial/guide/reference to creating a UDF is assuming some knowledge that I do not have yet. How can I create/use the UDFRowSequence functionality in Hortonworks install of hive?

Upvotes: 0

Views: 3605

Answers (2)

Kaustuv
Kaustuv

Reputation: 788

Copy jar file inside $HIVE_HOME/lib and restart hive client

cp full_path_to_jar_file $HIVE_HOME/lib/

Upvotes: 0

madhu
madhu

Reputation: 1170

In order to use the UDF inside Hive, compile the Java code and package the UDF bytecode class file into a JAR file. Then, open your Hive session, add the JAR to the classpath 

hive> ADD JAR full path to jar file;

The path here needs to be the full path of your local filesystem where you have to put your jar file.

and use a CREATE FUNCTION statement to define a function that uses the Java class:

hive> CREATE TEMPORARY FUNCTION functionname
> AS 'classname with full package name';

Then you can use the functionname in your hive session.

The path ql/src/java/org/apache/hadoop/hive/ql/udf/generic/ is actually referring to the package name of java class.

Upvotes: 2

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