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

Class GenericUDAFSum.GenericUDAFSumHiveDecimal

java.lang.Object

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

org.apache.hadoop.hive.ql.udf.generic.GenericUDAFSum.GenericUDAFSumEvaluator<org.apache.hadoop.hive.serde2.io.HiveDecimalWritable>

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

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

GenericUDAFSumEmptyIsZero.SumHiveDecimalZeroIfEmpty

Enclosing class:

GenericUDAFSum

public static class GenericUDAFSum.GenericUDAFSumHiveDecimal
extends GenericUDAFSum.GenericUDAFSumEvaluator<org.apache.hadoop.hive.serde2.io.HiveDecimalWritable>

GenericUDAFSumHiveDecimal.

Nested Class Summary

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.GenericUDAFSum.GenericUDAFSumEvaluator

inputOI, isWindowing, outputOI, result, sumDistinct

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

partitionEvaluator

Constructor Summary

Constructors

Constructor and Description
GenericUDAFSumHiveDecimal()

Method Summary

Modifier and Type	Method and Description
protected BasePartitionEvaluator	createPartitionEvaluator(WindowFrameDef winFrame, PTFPartition partition, List<PTFExpressionDef> parameters, ObjectInspector outputOI) This class needs to be overridden by the child class to implement function specific evaluator.
GenericUDAFEvaluator.AggregationBuffer	getNewAggregationBuffer() Get a new aggregation object.
static DecimalTypeInfo	getOutputDecimalTypeInfoForSum(int inputPrecision, int inputScale, GenericUDAFEvaluator.Mode mode)
GenericUDAFEvaluator	getWindowingEvaluator(WindowFrameDef wFrameDef) When evaluating an aggregates over a fixed Window, the naive way to compute results is to compute the aggregate for each row.
ObjectInspector	init(GenericUDAFEvaluator.Mode m, ObjectInspector[] parameters) Initialize the evaluator.
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.

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

isEligibleValue, isWindowingDistinct, setSumDistinct, setWindowing, terminatePartial

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericUDAFSumHiveDecimal

public GenericUDAFSumHiveDecimal()

Method Detail

init

public ObjectInspector init(GenericUDAFEvaluator.Mode m,
                            ObjectInspector[] parameters)
                     throws HiveException

Description copied from class: GenericUDAFEvaluator

Initialize the evaluator.

Overrides:

init in class GenericUDAFEvaluator

Parameters:

m - The mode of aggregation.

parameters - The ObjectInspector for the parameters: In PARTIAL1 and COMPLETE mode, the parameters are original data; In PARTIAL2 and FINAL mode, the parameters are just partial aggregations (in that case, the array will always have a single element).

Returns:

The ObjectInspector for the return value. In PARTIAL1 and PARTIAL2 mode, the ObjectInspector for the return value of terminatePartial() call; In FINAL and COMPLETE mode, the ObjectInspector for the return value of terminate() call. NOTE: We need ObjectInspector[] (in addition to the TypeInfo[] in GenericUDAFResolver) for 2 reasons: 1. ObjectInspector contains more information than TypeInfo; and GenericUDAFEvaluator.init at execution time. 2. We call GenericUDAFResolver.getEvaluator at compilation time,

Throws:

HiveException

getOutputDecimalTypeInfoForSum

public static DecimalTypeInfo getOutputDecimalTypeInfoForSum(int inputPrecision,
                                                             int inputScale,
                                                             GenericUDAFEvaluator.Mode mode)

getNewAggregationBuffer

public GenericUDAFEvaluator.AggregationBuffer getNewAggregationBuffer()
                                                               throws HiveException

Description copied from class: GenericUDAFEvaluator

Get a new aggregation object.

Specified by:

getNewAggregationBuffer in class GenericUDAFEvaluator

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.

Specified by:

reset in class GenericUDAFEvaluator

Throws:

HiveException

iterate

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

Description copied from class: GenericUDAFEvaluator

Iterate through original data.

Specified by:

iterate in class GenericUDAFEvaluator

parameters - The objects of parameters.

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.

Specified by:

merge in class GenericUDAFEvaluator

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.

Specified by:

terminate in class GenericUDAFEvaluator

Returns:

final aggregation result.

Throws:

HiveException

getWindowingEvaluator

public GenericUDAFEvaluator getWindowingEvaluator(WindowFrameDef wFrameDef)

Description copied from class: GenericUDAFEvaluator

When evaluating an aggregates over a fixed Window, the naive way to compute results is to compute the aggregate for each row. But often there is a way to compute results in a more efficient manner. This method enables the basic evaluator to provide a function object that does the job in a more efficient manner.

This method is called after this Evaluator is initialized. The returned Function must be initialized. It is passed the 'window' of aggregation for each row.

Overrides:

getWindowingEvaluator in class GenericUDAFEvaluator

Parameters:

wFrameDef - the Window definition in play for this evaluation.

Returns:

null implies that this fn cannot be processed in Streaming mode. So each row is evaluated independently.

createPartitionEvaluator

protected BasePartitionEvaluator createPartitionEvaluator(WindowFrameDef winFrame,
                                                          PTFPartition partition,
                                                          List<PTFExpressionDef> parameters,
                                                          ObjectInspector outputOI)

Description copied from class: GenericUDAFEvaluator

This class needs to be overridden by the child class to implement function specific evaluator.

Overrides:

createPartitionEvaluator in class GenericUDAFEvaluator