question Re: How can I create a udf in impala in Support Questions

How can I create a udf in impala

drgenious — Mon, 22 Mar 2021 06:56:39 GMT

I perform many queries with the below statement and I thought that instead of writing over and over again the same cases if it is possible to create a UDF in impala to handle this like sql server.

(select people, sum(new_money) as new_money from ( select people, case when pocket_01 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_02 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_03 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_04 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_05 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_06 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end + case when pocket_07 = 'leather' then sum(nvl(money,0.0))/100 else 0.0 end ) as new_money from bank where date = '20201010' ) target group by people ) as target

Is this possible? I have searched everywhere to find a simple example of how to create a udf but I only found this in the cloudera documentation which didnt help me a lot.

Re: How can I create a udf in impala

Daming Xue — Mon, 22 Mar 2021 06:59:39 GMT

The documentation is here:

https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/impala_udf.html

You can either implement Impala UDF using C++ or Hive UDF using Java

Re: How can I create a udf in impala

drgenious — Mon, 22 Mar 2021 07:01:54 GMT

Thanks for your quick response. Although I wrote that I have read clouderas documentation about UDFS and it didnt help me a lot. Is there any source with examples?

Re: How can I create a udf in impala

Daming Xue — Mon, 22 Mar 2021 07:10:17 GMT

Some community posts:

https://data-flair.training/blogs/impala-udf/

https://bigdatalatte.wordpress.com/2015/06/04/writing-java-udfs-in-impala/

https://blog.clairvoyantsoft.com/impala-udf-in-c-cf8a8f4a17c9