org.pentaho.aggdes.algorithm

Interface Algorithm

All Superinterfaces:

Component

All Known Implementing Classes:

AdaptiveMonteCarloAlgorithm, AlgorithmImpl, ExhaustiveLatticeAlgorithm, MonteCarloAlgorithm

public interface Algorithm
extends Component

Algorithm that takes a star schema and recommends a set of aggregate tables.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Algorithm.CostBenefit Collection of metrics describing the cost and benefit of instantiating a particular Aggregate.
static class	Algorithm.ParameterEnum Enumeration of parameters common to all algorithms.

Method Summary

Methods

Modifier and Type	Method and Description
void	cancel() Cancels a run.
List<Algorithm.CostBenefit>	computeAggregateCosts(Schema schema, Map<Parameter,Object> parameterValues, List<Aggregate> aggregateList) Computes cost/benefit metrics for a list of Aggregates.
Aggregate	createAggregate(Schema schema, List<Attribute> attributeList) Creates an Aggregate.
Result	run(Schema schema, Map<Parameter,Object> parameterValues, Progress progress) Runs the optimization algorithm to produces a set of recommended aggregate tables.

Methods inherited from interface org.pentaho.aggdes.model.Component

getName, getParameters

Method Detail

run

Result run(Schema schema,
         Map<Parameter,Object> parameterValues,
         Progress progress)

Runs the optimization algorithm to produces a set of recommended aggregate tables.

The allowable parameters are specified by the Component.getParameters() method.

Returns null if another thread called cancel() and there is no useful result.

Parameters:

schema - Schema

parameterValues - Parameter values

progress - Progress callback

Returns:

Set of recommended aggregate tables, or null if another thread called cancel() and there is no useful result

cancel

void cancel()

Cancels a run.

Call this method from another thread.

Some algorithms are able to return a result if they are canceled before they run to completion; if so, the run(org.pentaho.aggdes.model.Schema, java.util.Map<org.pentaho.aggdes.model.Parameter, java.lang.Object>, org.pentaho.aggdes.algorithm.Progress) method will return that result; otherwise run(org.pentaho.aggdes.model.Schema, java.util.Map<org.pentaho.aggdes.model.Parameter, java.lang.Object>, org.pentaho.aggdes.algorithm.Progress) returns null.

createAggregate

Aggregate createAggregate(Schema schema,
                        List<Attribute> attributeList)

Creates an Aggregate.

Parameters:

schema - Schema object

attributeList - List of attributes

Returns:

Aggregate

computeAggregateCosts

List<Algorithm.CostBenefit> computeAggregateCosts(Schema schema,
                                                Map<Parameter,Object> parameterValues,
                                                List<Aggregate> aggregateList)

Computes cost/benefit metrics for a list of Aggregates.

The aggregates must have been created using the #createAggregate(java.util.List) method.

The order of the list is important: the benefit of the i^th aggregate is its benefit over the previous aggregates 0, ... i - 1.

This method is not thread safe; you must not call it while calling another method on this Algorithm object. The Algorithm object may or may not have been previously used to generate a set of aggregates (see run(org.pentaho.aggdes.model.Schema, java.util.Map<org.pentaho.aggdes.model.Parameter, java.lang.Object>, org.pentaho.aggdes.algorithm.Progress)).

Parameters:

schema - Schema

parameterValues - Parameter values

aggregateList - List of aggregates

Returns:

list of cost/benefit for each aggregate in the list