huaxingao commented on a change in pull request #28104: [SPARK-31331][SQL][DOCS] Document Spark integration with Hive UDFs/UDAFs/UDTFs URL: https://github.com/apache/spark/pull/28104#discussion_r406001569
########## File path: docs/sql-ref-functions-udf-hive.md ########## @@ -19,4 +19,94 @@ license: | limitations under the License. --- -Integration with Hive UDFs/UDAFs/UDTFs \ No newline at end of file +### Description + +Spark SQL supports integration of Hive UDFs, UDAFs and UDTFs. Similar to Spark UDFs and UDAFs, Hive UDFs work on a single row as input and generate a single row as output, while Hive UDAFs operate on multiple rows and return a single aggregated row as a result. In addition, Hive also supports UDTFs (User Defined Tabular Functions) that act on one row as input and return multiple rows as output. To use Hive UDFs/UDAFs/UTFs, the user should register them in Spark, and then use them in Spark SQL queries. + +### Examples + +Hive has two UDF interfaces: [UDF](https://github.com/apache/hive/blob/master/udf/src/java/org/apache/hadoop/hive/ql/exec/UDF.java) and [GenericUDF](https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDF.java). +An example below uses [GenericUDFAbs](https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFAbs.java) derived from `GenericUDF`. + +<pre><code> +// Register `GenericUDFAbs` and use it in Spark SQL. +// Note that, if you use your own programmed one, you need to add a JAR containig it into a classpath, +// e.g., `spark.sql("ADD JAR yourHiveUDF.jar")`. +spark.sql("CREATE TEMPORARY FUNCTION testUDF AS 'org.apache.hadoop.hive.ql.udf.generic.GenericUDFAbs'") + +spark.sql("SELECT * FROM hiveUDFTestTable").show() Review comment: OK. Will convert to SQL ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
