Creating a Function

Function

DLI allows you to create and use user-defined functions (UDF) and user-defined table functions (UDTF) in Spark jobs.

Syntax

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CREATE [TEMPORARY] FUNCTION [db_name.]function_name AS class_name
  [USING resource,...]

resource: 
  : (JAR|FILE|ARCHIVE)file_uri

Precautions

• If a function with the same name exists in the database, the system reports an error.
• Only the Hive syntax can be used to create functions.
• If you specify the same class name for two UDFs, the functions conflict though the package names are different. Avoid this problem because it causes failure of job execution.

Keywords

• TEMPORARY: The created function is available only in the current session and is not persisted to the underlying metabase, if any. The database name cannot be specified for a temporary function.
• USING <resources>: resources to be loaded. It can be a list of JARs, files, or URIs.

Example

Create the mergeBill function.

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CREATE FUNCTION mergeBill AS 'com.xxx.hiveudf.MergeBill'
  using jar 'obs://onlyci-7/udf/MergeBill.jar';