ReductionAggregation#

public final class ReductionAggregation#

An aggregation that can be used for a reduce.

Method Summary

`all()`	All reduction.
`any()`	Any reduction.
`argMax()`	ArgMax Aggregation.
`argMin()`	ArgMin Aggregation.
`bitAnd()`	Bitwise AND aggregation, computing the bitwise AND of all non-null values.
`bitOr()`	Bitwise OR aggregation, computing the bitwise OR of all non-null values.
`bitXor()`	Bitwise XOR aggregation, computing the bitwise XOR of all non-null values.
`collectList()`
`collectList(NullPolicy nullPolicy)`	Collect the values into a list.
`collectSet()`	Collect the values into a set.
`collectSet(NullPolicy nullPolicy, NullEquality nullEquality, NaNEquality nanEquality)`	Collect the values into a set.
`createTDigest(int delta)`	tDigest reduction.
`equals(Object other)`
`hashCode()`
`histogram()`	Create HistogramAggregation, computing the frequencies for each unique row.
`hostUDF(HostUDFWrapper wrapper)`	Execute a reduction using a host-side user-defined function (UDF).
`max()`	Max Aggregation.
`mean()`	Arithmetic mean reduction.
`median()`	Median reduction.
`mergeHistogram()`	Create MergeHistogramAggregation, to merge multiple histograms.
`mergeLists()`	Merge the partial lists produced by multiple CollectListAggregations.
`mergeSets()`	Merge the partial sets produced by multiple CollectSetAggregations.
`mergeSets(NullEquality nullEquality, NaNEquality nanEquality)`	Merge the partial sets produced by multiple CollectSetAggregations.
`mergeTDigest(int delta)`	tDigest merge reduction.
`min()`	Min Aggregation.
`nth(int offset)`	Get the nth, non-null, element in a group.
`nth(int offset, NullPolicy nullPolicy)`	Get the nth element in a group.
`nunique()`	Number of unique, non-null, elements.
`nunique(NullPolicy nullPolicy)`	Number of unique elements.
`product()`	Product Aggregation.
`quantile(QuantileMethod method, double... quantiles)`	Aggregate to compute various quantiles.
`quantile(double... quantiles)`	Aggregate to compute the specified quantiles.
`standardDeviation()`	Standard deviation aggregation with 1 as the delta degrees of freedom.
`standardDeviation(int ddof)`	Standard deviation aggregation.
`sum()`	Sum Aggregation.
`sumOfSquares()`	Sum of squares reduction.
`sumOverflow()`	Sum reduction that also reports overflow.
`variance()`	Variance aggregation with 1 as the delta degrees of freedom.
`variance(int ddof)`	Variance aggregation.

Methods

public int hashCode()#

public boolean equals(Object other)#

Static Methods

public static ReductionAggregation sum()#: Sum Aggregation.

public static ReductionAggregation sumOverflow()#

Sum reduction that also reports overflow.

The result is a struct scalar with children {sum: same type as input, overflow: BOOL8}. The input may be any signed integer type (INT8/16/32/64) or fixed-point decimal (DECIMAL32/64/128). On overflow the sum value is unspecified; the boolean flag is the source of truth.

public static ReductionAggregation product()#: Product Aggregation.

public static ReductionAggregation argMin()#: ArgMin Aggregation.

public static ReductionAggregation argMax()#: ArgMax Aggregation.

public static ReductionAggregation min()#: Min Aggregation.

public static ReductionAggregation max()#: Max Aggregation.

public static ReductionAggregation any()#

Any reduction.

Produces a true or 1, depending on the output type, if any of the elements in the range are true or non-zero, otherwise produces a false or 0. Null values are skipped.

public static ReductionAggregation all()#

All reduction.

Produces true or 1, depending on the output type, if all of the elements in the range are true or non-zero, otherwise produces a false or 0. Null values are skipped.

public static ReductionAggregation sumOfSquares()#: Sum of squares reduction.

public static ReductionAggregation mean()#: Arithmetic mean reduction.

public static ReductionAggregation variance()#: Variance aggregation with 1 as the delta degrees of freedom.

public static ReductionAggregation variance(int ddof)#

Variance aggregation.

Parameters:: ddof – delta degrees of freedom. The divisor used in calculation of variance is N - ddof, where N is the population size.

public static ReductionAggregation standardDeviation()#: Standard deviation aggregation with 1 as the delta degrees of freedom.

public static ReductionAggregation standardDeviation(int ddof)#

Standard deviation aggregation.

Parameters:: ddof – delta degrees of freedom. The divisor used in calculation of std is N - ddof, where N is the population size.

public static ReductionAggregation median()#: Median reduction.

public static ReductionAggregation quantile(double... quantiles)#

Aggregate to compute the specified quantiles.

Uses linear interpolation by default.

public static ReductionAggregation quantile( QuantileMethod method, double... quantiles )#: Aggregate to compute various quantiles.

public static ReductionAggregation nunique()#: Number of unique, non-null, elements.

public static ReductionAggregation nunique(NullPolicy nullPolicy)#

Number of unique elements.

Parameters:: nullPolicy – INCLUDE if nulls should be counted else EXCLUDE. If nulls are counted they compare as equal so multiple null values in a range would all only increase the count by 1.

public static ReductionAggregation nth(int offset)#

Get the nth, non-null, element in a group.

Parameters:: offset – the offset to look at. Negative numbers go from the end of the group. Any value outside of the group range results in a null.

public static ReductionAggregation nth( int offset, NullPolicy nullPolicy )#

Get the nth element in a group.

Parameters:

offset – the offset to look at. Negative numbers go from the end of the group. Any value outside of the group range results in a null.
nullPolicy – INCLUDE if nulls should be included in the aggregation or EXCLUDE if they should be skipped.

public static ReductionAggregation createTDigest(int delta)#: tDigest reduction.

public static ReductionAggregation mergeTDigest(int delta)#: tDigest merge reduction.

public static ReductionAggregation collectList()#

public static ReductionAggregation collectList(NullPolicy nullPolicy)#

Collect the values into a list.

Parameters:: nullPolicy – Indicates whether to include/exclude nulls during collection.

public static ReductionAggregation collectSet()#

Collect the values into a set.

All null values will be excluded, and all NaN values are regarded as unique instances.

public static ReductionAggregation collectSet( NullPolicy nullPolicy, NullEquality nullEquality, NaNEquality nanEquality )#

Collect the values into a set.

Parameters:

nullPolicy – Indicates whether to include/exclude nulls during collection.
nullEquality – Flag to specify whether null entries within each list should be considered equal.
nanEquality – Flag to specify whether NaN values in floating point column should be considered equal.

public static ReductionAggregation mergeLists()#

Merge the partial lists produced by multiple CollectListAggregations.

NOTICE: The partial lists to be merged should NOT include any null list element (but can include null list entries).

public static ReductionAggregation mergeSets()#

Merge the partial sets produced by multiple CollectSetAggregations.

Each null/NaN value will be regarded as a unique instance.

public static ReductionAggregation mergeSets( NullEquality nullEquality, NaNEquality nanEquality )#

Merge the partial sets produced by multiple CollectSetAggregations.

Parameters:

nullEquality – Flag to specify whether null entries within each list should be considered equal.
nanEquality – Flag to specify whether NaN values in floating point column should be considered equal.

public static ReductionAggregation hostUDF(HostUDFWrapper wrapper)#

Execute a reduction using a host-side user-defined function (UDF).

Parameters:: wrapper – The wrapper for the native host UDF instance.
Returns:: A new ReductionAggregation instance

public static ReductionAggregation histogram()#

Create HistogramAggregation, computing the frequencies for each unique row.

Returns:: A structs column in which the first child stores unique rows from the input and the second child stores their corresponding frequencies.

public static ReductionAggregation mergeHistogram()#

Create MergeHistogramAggregation, to merge multiple histograms.

Returns:: A new histogram in which the frequencies of the unique rows are sum up.

public static ReductionAggregation bitAnd()#: Bitwise AND aggregation, computing the bitwise AND of all non-null values.

public static ReductionAggregation bitOr()#: Bitwise OR aggregation, computing the bitwise OR of all non-null values.

public static ReductionAggregation bitXor()#: Bitwise XOR aggregation, computing the bitwise XOR of all non-null values.