org.apache.hadoop.hive.contrib.udaf.example

Class UDAFExampleGroupConcat

java.lang.Object

org.apache.hadoop.hive.ql.exec.UDAF

org.apache.hadoop.hive.contrib.udaf.example.UDAFExampleGroupConcat

public class UDAFExampleGroupConcat
extends UDAF

This is a simple UDAF that concatenates all arguments from different rows into a single string. It should be very easy to follow and can be used as an example for writing new UDAFs. Note that Hive internally uses a different mechanism (called GenericUDAF) to implement built-in aggregation functions, which are harder to program but more efficient.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	UDAFExampleGroupConcat.UDAFExampleGroupConcatEvaluator The actual class for doing the aggregation.

Constructor Summary

Constructors

Constructor and Description
UDAFExampleGroupConcat()

Method Summary

Methods inherited from class org.apache.hadoop.hive.ql.exec.UDAF

getResolver, setResolver

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UDAFExampleGroupConcat

public UDAFExampleGroupConcat()