Hi.
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/**
* @author thinker0
*
* TiaraUDFRank.
*/
@Description(name = "t_row_rank", value = "_FUNC_() - Returns a generated row
rank sequence number starting from 1")
@UDFType(deterministic = false)
public class TiaraRankUDF extends UDF {
private final LongWritable result = new LongWritable();
private final Text keepKeys = new Text();
private final Text keyArgs = new Text();
private static final byte[] NULL = "NULL".getBytes();
private static final byte[] SPLIT = ";".getBytes();
/**
*
*/
public TiaraRankUDF() {
keepKeys.clear();
keyArgs.clear();
}
/**
* @param rslv
*/
public TiaraRankUDF(UDFMethodResolver rslv) {
super(rslv);
}
/**
*
* @param args
* @return rank number
*/
public LongWritable evaluate(Text... args) {
keyArgs.clear();
for (Text arg : args) {
if (arg == null) {
keyArgs.append(NULL, 0, NULL.length);
} else {
final byte[] keyByte = arg.getBytes();
keyArgs.append(keyByte, 0, keyByte.length);
}
keyArgs.append(SPLIT, 0, SPLIT.length);
}
if (! keepKeys.toString().equals(keyArgs.toString())) {
keepKeys.set(keyArgs);
result.set(0);
}
result.set(result.get() + 1);
return result;
}
}
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On May 25, 2011, at 8:45 PM, 김영우 wrote:
> Hi All,
>
> I'm trying to convert Oracle SQL to HiveQL, esp Oracle Analytic functions. Is
> it possible to implement using Hive UDFs or workarounds?
> I would like to hear your experiences and advice.
>
> Thanks in advance.
>
> - Youngwoo
