com.yahoo.bard.webservice.druid.model.aggregation

Class CardinalityAggregation

java.lang.Object

com.yahoo.bard.webservice.druid.model.aggregation.Aggregation

com.yahoo.bard.webservice.druid.model.aggregation.CardinalityAggregation

All Implemented Interfaces:

MetricField

public class CardinalityAggregation
extends Aggregation

Creates a Druid cardinality aggregation.

Cardinality aggregators target dimension columns and not metric columns in their underlying data source, counting either dimension cardinality sums, or sums of dimension tuples

Does not support DimensionSpecs, only accept Strings as fieldNames

Constructor Summary

Constructors

Constructor and Description
CardinalityAggregation(String name, Set<Dimension> dimensions, boolean byRow) Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Set<Dimension>	getDependentDimensions() Get the dimensions, if any, this metric depends on.
String	getFieldName() Field name is not part of the Cardinality aggregation model in druid.
String	getType() The Type name for the aggregation in the druid configuration.
int	hashCode()
boolean	isByRow()
org.apache.commons.lang3.tuple.Pair<Aggregation,Aggregation>	nest() Cardinality aggregators cannot be safely nested due to correctness constraints which Bard does not currently support.
CardinalityAggregation	withByRow(boolean byRow) Build a copy with a given byRow values.
CardinalityAggregation	withDimensions(Set<Dimension> dimensions) Build a copy with a modified base set of dimensions.
CardinalityAggregation	withFieldName(String fieldName) Field name copy constructor is unsupported because cardinality metrics are built using dimensions backed by dimension druid names.
CardinalityAggregation	withName(String name) Creates a new Aggregation with the provided name.

Methods inherited from class com.yahoo.bard.webservice.druid.model.aggregation.Aggregation

getName, isFloatingPoint, isSketch, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CardinalityAggregation

public CardinalityAggregation(String name,
                              Set<Dimension> dimensions,
                              boolean byRow)

Constructor.

Parameters:

name - Name of the field

dimensions - The dimensions whose cardinality you want to capture

byRow - Whether to use Row or Value cardinality

Method Detail

isByRow

public boolean isByRow()

getFieldName

public String getFieldName()

Field name is not part of the Cardinality aggregation model in druid. Suppress this field.

Overrides:

getFieldName in class Aggregation

Returns:

empty string which denotes no underlying metric field

getType

public String getType()

Description copied from class: Aggregation

The Type name for the aggregation in the druid configuration.

Specified by:

getType in class Aggregation

Returns:

the druid 'type' string

getDependentDimensions

public Set<Dimension> getDependentDimensions()

Description copied from interface: MetricField

Get the dimensions, if any, this metric depends on.

Specified by:

getDependentDimensions in interface MetricField

Overrides:

getDependentDimensions in class Aggregation

Returns:

A set of dimensions required to satisfy this metric field

withName

public CardinalityAggregation withName(String name)

Description copied from class: Aggregation

Creates a new Aggregation with the provided name.

Specified by:

withName in class Aggregation

Parameters:

name - Name for the new aggregation

Returns:

subclass of Aggregation

withFieldName

public CardinalityAggregation withFieldName(String fieldName)

Field name copy constructor is unsupported because cardinality metrics are built using dimensions backed by dimension druid names.

Specified by:

withFieldName in class Aggregation

Parameters:

fieldName - Field name for the new aggregation

Returns:

Always throws an UnsupportedOperationException

withDimensions

public CardinalityAggregation withDimensions(Set<Dimension> dimensions)

Build a copy with a modified base set of dimensions.

Parameters:

dimensions - The dimensions for the new Cardinality Aggregation

Returns:

a copy of this aggregation with different underlying dimensions

withByRow

public CardinalityAggregation withByRow(boolean byRow)

Build a copy with a given byRow values.

Parameters:

byRow - The by row value to change to

Returns:

a copy of this aggregation with different byRow value

nest

public org.apache.commons.lang3.tuple.Pair<Aggregation,Aggregation> nest()

Cardinality aggregators cannot be safely nested due to correctness constraints which Bard does not currently support.

Overrides:

nest in class Aggregation

Returns:

Always throws an exception

equals

public boolean equals(Object o)

Overrides:

equals in class Aggregation

hashCode

public int hashCode()

Overrides:

hashCode in class Aggregation