Package mondrian.rolap

Class RolapAggregator.AvgFromAvg

java.lang.Object

mondrian.olap.EnumeratedValues.BasicValue

mondrian.rolap.RolapAggregator

mondrian.rolap.RolapAggregator.BaseAggor

mondrian.rolap.RolapAggregator.AvgFromAvg

All Implemented Interfaces:

Aggregator, EnumeratedValues.Value

Enclosing class:

RolapAggregator

public static class RolapAggregator.AvgFromAvg
extends RolapAggregator.BaseAggor

Aggregator used for aggregate tables implementing the average aggregator.

It uses the aggregate table fact_count column and an average measure to create the query used to generate an average:

avg == sum(column_sum * factcount) / sum(factcount).

If the fact table has both a sum and average over the same column and the aggregate table only has a average and fact count column, then the average aggregator can be generated using this aggregator.

Nested Class Summary

Nested classes/interfaces inherited from class mondrian.rolap.RolapAggregator

RolapAggregator.AvgFromAvg, RolapAggregator.AvgFromSum, RolapAggregator.BaseAggor, RolapAggregator.SumFromAvg

Field Summary

Fields inherited from class mondrian.rolap.RolapAggregator.BaseAggor

factCountExpr

Fields inherited from class mondrian.rolap.RolapAggregator

Avg, Count, DistinctCount, enumeration, Max, Min, Sum

Fields inherited from class mondrian.olap.EnumeratedValues.BasicValue

description, name, ordinal

Constructor Summary

Constructors

Constructor	Description
AvgFromAvg(String factCountExpr)

Method Summary

Modifier and Type	Method	Description
boolean	alwaysRequiresFactColumn()
String	getExpression(String operand)	Returns the expression to apply this aggregator to an operand.
String	getScalarExpression(String operand)

Methods inherited from class mondrian.rolap.RolapAggregator.BaseAggor

aggregate

Methods inherited from class mondrian.rolap.RolapAggregator

aggregate, getNonDistinctAggregator, getRollup, isDistinct, supportsFastAggregates

Methods inherited from class mondrian.olap.EnumeratedValues.BasicValue

equals, getDescription, getName, getOrdinal, toString, unexpected

Methods inherited from class java.lang.Object

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

Constructor Details

AvgFromAvg

public AvgFromAvg(String factCountExpr)

Method Details

getExpression

public String getExpression(String operand)

Description copied from class: RolapAggregator

Returns the expression to apply this aggregator to an operand. For example, getExpression("emp.sal") returns "sum(emp.sal)".

Overrides:

getExpression in class RolapAggregator

alwaysRequiresFactColumn

public boolean alwaysRequiresFactColumn()

Specified by:

alwaysRequiresFactColumn in class RolapAggregator.BaseAggor

getScalarExpression

public String getScalarExpression(String operand)

Specified by:

getScalarExpression in class RolapAggregator.BaseAggor