mondrian.spi.impl

Class DataSourceChangeListenerImpl

java.lang.Object

mondrian.spi.impl.DataSourceChangeListenerImpl

All Implemented Interfaces:

DataSourceChangeListener

public class DataSourceChangeListenerImpl
extends Object
implements DataSourceChangeListener

Default implementation of a data source change listener that always returns that the datasource is unchanged. A change listener can be specified in the connection string. It is used to ask what is changed in the datasource (e.g. database). Everytime mondrian has to decide whether it will use data from cache, it will call the change listener. When the change listener tells mondrian the datasource has changed for a dimension, cube, ... then mondrian will flush the cache and read from database again. It is specified in the connection string, like this:

Jdbc=jdbc:odbc:MondrianFoodMart; JdbcUser=ziggy; JdbcPassword=stardust; DataSourceChangeListener=com.acme.MyChangeListener;

This class should be called in mondrian before any data is read, so even before cache is build. This way, the plugin is able to register the first timestamp mondrian tries to read the datasource.

Since:

Dec 12, 2006

Author:

Bart Pappyn

Constructor Summary

Constructors

Constructor and Description
DataSourceChangeListenerImpl() Creates a new instance of DataSourceChangeListenerImpl

Method Summary

Modifier and Type	Method and Description
String	getTableName(RolapHierarchy hierarchy)
boolean	isAggregationChanged(AggregationKey aggregation) Checks if the given aggregation has changed since the previous time this function was called.
boolean	isHierarchyChanged(RolapHierarchy hierarchy) Checks if the given hierarchy has changed since the previous time this function was called.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataSourceChangeListenerImpl

public DataSourceChangeListenerImpl()

Creates a new instance of DataSourceChangeListenerImpl

Method Detail

isHierarchyChanged

public boolean isHierarchyChanged(RolapHierarchy hierarchy)

Description copied from interface: DataSourceChangeListener

Checks if the given hierarchy has changed since the previous time this function was called. The first time, this function will be called when the cache is still empty. This is because the plugin is able to register the first timestamp the function was accessed. It is highly recommended to optimize the plugin and minimize the time needed to evaluate this function, because this plugin is called many times for each mondrian query.

Specified by:

isHierarchyChanged in interface DataSourceChangeListener

isAggregationChanged

public boolean isAggregationChanged(AggregationKey aggregation)

Description copied from interface: DataSourceChangeListener

Checks if the given aggregation has changed since the previous time this function was called. The first time, this function will be called when the cache is still empty. This is because the plugin is able to register the first timestamp the function was accessed.

Specified by:

isAggregationChanged in interface DataSourceChangeListener

getTableName

public String getTableName(RolapHierarchy hierarchy)