Package com.illumon.iris.db.v2.by

Class DistinctStateFactory

java.lang.Object

com.illumon.iris.db.v2.by.ReaggregatableStatefactory

com.illumon.iris.db.v2.by.IterativeOperatorStateFactory

com.illumon.iris.db.v2.by.DistinctStateFactory

All Implemented Interfaces:

BasicDeflatable<DistinctStateFactory>, AggregationStateFactory, IterativeChunkedOperatorFactory

public class DistinctStateFactory
extends IterativeOperatorStateFactory
implements BasicDeflatable<DistinctStateFactory>

An Iterative state factory that computes the count of distinct items within a particular state. It supports rollups, and converts itself into a Sum at the second level of the rollup.

Method Summary

Modifier and Type	Method	Description
boolean	countNulls()
BasicInflatable<DistinctStateFactory>	deflate()
IterativeChunkedAggregationOperator	getChunkedOperator(Class type, String name, boolean exposeInternalColumns)
AggregationMemoKey	getMemoKey()	Produces a MemoKey for this aggregation state factory.
String	toString()

Methods inherited from class java.lang.Object

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

Method Details

getMemoKey

public AggregationMemoKey getMemoKey()

Description copied from interface: AggregationStateFactory

Produces a MemoKey for this aggregation state factory.

If two AggregationStateFactories have equal memoKeys, then Table.by(com.illumon.iris.db.v2.by.AggregationStateFactory, com.illumon.iris.db.v2.select.SelectColumn...) operations that have the same group by columns may be memoized. In that case instead of recomputing the result; the original result will be used.

If null is returned, the operation will not be memoized.

Specified by:

getMemoKey in interface AggregationStateFactory

Returns:

an AggregationMemoKey, null if this operation can not be memoized.

getChunkedOperator

public IterativeChunkedAggregationOperator getChunkedOperator(Class type, String name, boolean exposeInternalColumns)

Specified by:

getChunkedOperator in interface IterativeChunkedOperatorFactory

Specified by:

getChunkedOperator in class IterativeOperatorStateFactory

countNulls

public boolean countNulls()

toString

public String toString()

Overrides:

toString in class Object

deflate

public BasicInflatable<DistinctStateFactory> deflate()

Specified by:

deflate in interface BasicDeflatable<DistinctStateFactory>