Bug 182680 Use feature of new Aggregation framework of Data Engine.
DataEngine will implement new aggregation framework in 2.2.0RC0. After the implementation is finished Engine should go ahead to use new column bindings in definition of map/highlight.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/DataExtractionTask.java
public void selectColumns( String[] columnNames )
	{
		selectedColumns = columnNames;
	}
	public IExtractionResults extract( ) throws EngineException
	{
		String rsetName = resultSetName;
		if ( rsetName == null )
		{
			if ( instanceId != null )
			{
				rsetName = instanceId2RsetName( instanceId );
			}
		}
		if ( rsetName != null )
		{
			return extractByResultSetName( rsetName );
		}
		if (instanceId != null)
		{
			return extractByInstanceID( instanceId);
		}
		return null;
	}
	/*
	 * export result directly from result set name
	 */
	private IExtractionResults extractByResultSetName( String rsetName )
			throws EngineException
	{