Which command is used to register a UDF in Spark?

Which command is used to register a UDF in Spark?

• A. defineUDF()
• B. spark.udf.register()
• C. createUDF()
• D. registerUDF()

Answer: (B)

The command used to register a User Defined Function (UDF) in Spark is `spark.udf.register()`. This function allows you to define a UDF that can then be used in Spark SQL queries. By using this command, you provide the UDF name and the function itself, enabling Spark to recognize and execute it within SQL contexts. The `spark.udf.register()` function is an essential part of extending the capabilities of Spark by allowing users to write custom functions in Python, which can be executed on a distributed dataset. This versatility is particularly useful when built-in functions do not meet specific data processing needs. The other options mentioned do not correspond to the correct syntax or functionality provided by Spark for registering UDFs. For instance, `defineUDF()`, `createUDF()`, and `registerUDF()` are not valid commands or do not exist in the Spark API for this particular task, which solidifies `spark.udf.register()` as the accurate choice for registering UDFs in Spark.

The command used to register a User Defined Function (UDF) in Spark is spark.udf.register(). This function allows you to define a UDF that can then be used in Spark SQL queries. By using this command, you provide the UDF name and the function itself, enabling Spark to recognize and execute it within SQL contexts.

The spark.udf.register() function is an essential part of extending the capabilities of Spark by allowing users to write custom functions in Python, which can be executed on a distributed dataset. This versatility is particularly useful when built-in functions do not meet specific data processing needs.

The other options mentioned do not correspond to the correct syntax or functionality provided by Spark for registering UDFs. For instance, defineUDF(), createUDF(), and registerUDF() are not valid commands or do not exist in the Spark API for this particular task, which solidifies spark.udf.register() as the accurate choice for registering UDFs in Spark.