MOJAthenaUDFs

AWS ATHENA UDFs for Record Linkage

Need Java 1.8 / Maven installed. Installation of both through SDKMAN is recommended

HOW TO BUILD JAR and create the lambda function:

mvn package clean #to check if it compiles
mvn clean install -DskipTests

Create a lambda function (make sure that lambda role is created before this).Either use the web interface or the below command:

aws lambda create-function
--function-name athenaudf
--runtime java8
--role arn:aws:iam::3242345446345:role/serverlessrepo-AthenaUserDefin
--handler com.awssupport.athena.udfs.MOJAthenaUserDefinedFunctions
--timeout 900
--zip-file fileb://./target/MOJAthenaUserDefinedFunctions-1.0-SNAPSHOT --region eu-west-1

• Go to Athena and make sure that Console is pointing to Engine version 2

• Run below query on ATHENA to test UDF:

USING EXTERNAL FUNCTION dm(input VARCHAR) RETURNS VARCHAR LAMBDA 'athenaudf' SELECT dm('Hello')

---

Progress

v.1.0.0

get this mechanism working / compiling and outputing a jar. Next step: Test that its working on Athena.

• double metaphone should be ready and working now

• Jaro Winkler from Apache Commons also compiles sucessfully and has a scalar interface , in the way UDFs work in Athena : it needs input of the form "TEXT_FROM_COL1####TEXT_FROM_COL2" where #### is the seperator of the two column strings As the documentation [see reference 1] points out:

    Scalar UDFs only – Athena only supports scalar UDFs, which process one row at a time and return a single column value. 
    Athena passes a batch of rows, potentially in parallel, to the UDF each time it invokes Lambda
  

---

References

[1] Athena querying udfs

[2] Athena UDFs: creating and deploying

[3] AWS Athena UDF access to lambda context