org.apache.hadoop.hive.ql.udf.generic

Class GenericUDAFDenseRank.GenericUDAFHypotheticalSetDenseRankEvaluator

java.lang.Object

org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator

org.apache.hadoop.hive.ql.udf.generic.GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

org.apache.hadoop.hive.ql.udf.generic.GenericUDAFDenseRank.GenericUDAFHypotheticalSetDenseRankEvaluator

All Implemented Interfaces:

Closeable, AutoCloseable

Enclosing class:

GenericUDAFDenseRank

public static class GenericUDAFDenseRank.GenericUDAFHypotheticalSetDenseRankEvaluator
extends GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

Evaluator for calculating the dense rank. SELECT dense_rank(expression1[, expressionn]*) WITHIN GROUP (ORDER BY col1[, coln]*) Implementation is based on hypothetical rank calculation but the group of values are considered distinct. Since the source of the input stream is not sorted a HashSet is used for filter out duplicate values which can lead to OOM in large data sets.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator.CompareResult, GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator.HypotheticalSetRankBuffer, GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator.RankAssets

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator

GenericUDAFEvaluator.AbstractAggregationBuffer, GenericUDAFEvaluator.AggregationBuffer, GenericUDAFEvaluator.AggregationType, GenericUDAFEvaluator.Mode

Field Summary

Fields inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

COUNT_FIELD, PARTIAL_RANK_OI, RANK_FIELD

Fields inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator

partitionEvaluator

Constructor Summary

Constructors

Constructor and Description
GenericUDAFHypotheticalSetDenseRankEvaluator()

Method Summary

Modifier and Type	Method and Description
GenericUDAFEvaluator.AggregationBuffer	getNewAggregationBuffer() Get a new aggregation object.
protected void	initPartial2AndFinalOI(ObjectInspector[] parameters)
void	iterate(GenericUDAFEvaluator.AggregationBuffer agg, Object[] parameters) Iterate through original data.
void	merge(GenericUDAFEvaluator.AggregationBuffer agg, Object partial) Merge with partial aggregation result.
void	reset(GenericUDAFEvaluator.AggregationBuffer agg) Reset the aggregation.
Object	terminate(GenericUDAFEvaluator.AggregationBuffer agg) Get final aggregation result.
Object	terminatePartial(GenericUDAFEvaluator.AggregationBuffer agg) Get partial aggregation result.

Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

compare, init

Methods inherited from class org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator

aggregate, close, configure, createPartitionEvaluator, estimate, evaluate, getExprString, getPartitionWindowingEvaluator, getWindowingEvaluator, isEstimable

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericUDAFHypotheticalSetDenseRankEvaluator

public GenericUDAFHypotheticalSetDenseRankEvaluator()

Method Detail

initPartial2AndFinalOI

protected void initPartial2AndFinalOI(ObjectInspector[] parameters)

Overrides:

initPartial2AndFinalOI in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

getNewAggregationBuffer

public GenericUDAFEvaluator.AggregationBuffer getNewAggregationBuffer()
                                                               throws HiveException

Description copied from class: GenericUDAFEvaluator

Get a new aggregation object.

Overrides:

getNewAggregationBuffer in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

Throws:

HiveException

reset

public void reset(GenericUDAFEvaluator.AggregationBuffer agg)
           throws HiveException

Description copied from class: GenericUDAFEvaluator

Reset the aggregation. This is useful if we want to reuse the same aggregation.

Overrides:

reset in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

Throws:

HiveException

iterate

public void iterate(GenericUDAFEvaluator.AggregationBuffer agg,
                    Object[] parameters)
             throws HiveException

Description copied from class: GenericUDAFEvaluator

Iterate through original data.

Overrides:

iterate in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

parameters - The objects of parameters.

Throws:

HiveException

terminatePartial

public Object terminatePartial(GenericUDAFEvaluator.AggregationBuffer agg)
                        throws HiveException

Description copied from class: GenericUDAFEvaluator

Get partial aggregation result.

Overrides:

terminatePartial in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

Returns:

partial aggregation result.

Throws:

HiveException

merge

public void merge(GenericUDAFEvaluator.AggregationBuffer agg,
                  Object partial)
           throws HiveException

Description copied from class: GenericUDAFEvaluator

Merge with partial aggregation result. NOTE: null might be passed in case there is no input data.

Overrides:

merge in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

partial - The partial aggregation result.

Throws:

HiveException

terminate

public Object terminate(GenericUDAFEvaluator.AggregationBuffer agg)
                 throws HiveException

Description copied from class: GenericUDAFEvaluator

Get final aggregation result.

Overrides:

terminate in class GenericUDAFRank.GenericUDAFHypotheticalSetRankEvaluator

Returns:

final aggregation result.

Throws:

HiveException