In this section, we introduce the UDAF code template, which extends from the org.apache.hadoop.hive.ql.exec.UDAF class. The code template is as follows:
package com.packtpub.hive.essentials.hiveudaf;
import org.apache.hadoop.hive.ql.exec.UDAF;
import org.apache.hadoop.hive.ql.exec.UDAFEvaluator;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.udf.UDFType;
@Description(
name = "udaf_name",
value = "_FUNC_(arg1, arg2, ... argN) - description for the function",
extended = "description with more details, such as syntax, examples."
)
@UDFType(deterministic = false, stateful = true)
public final class udaf_name extends UDAF {
/**
* The internal state of an aggregation function.
*
* Note that ...
