Package org.pentaho.aggdes.algorithm
package org.pentaho.aggdes.algorithm
Defines the interface of the Aggregate Designer algorithm and supporting
classes.
The Aggregate Designer consists of a number of components:
- The schema loader component
(
SchemaLoader) reads a star schema and presents the algorithm with aSchemaobject and embeddedTableandAttributeobjects. - The algorithm component
(
Algorithm) tries to find the most efficient set of aggregates for a given schema. A set of aggregates is efficient if it enables any expected query to evaluate quickly yet has a reasonable cost in terms of disk space and load time. - The result handler component
(
org.pentaho.aggdes.output.ResultHandler) converts the result of the algorithm into a useful form such as a script of CREATE TABLE statements to create aggregate tables and INSERT statements to populate them. A result handler is not necessary if you are invoking the algorithm programmatically and your program will process the (Result)object produced by the algorithm itself.
Each of the components is specified a particular Java interface that extends
Component. There is a default
implementation for each component, but you can provide your own.
There is a command-line utility org.pentaho.aggdes.model.Main
to allow you to invoke the algorithm. You can choose which implementation
of each component, and provide parameters to each component.
-
ClassDescriptionAlgorithm that takes a star schema and recommends a set of aggregate tables.Collection of metrics describing the cost and benefit of instantiating a particular
Aggregate.Enumeration of parameters common to all algorithms.Callback to report progress.Recommendations produced by an aggregate table advisor job.