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/GetParameterDefinitionTask.java
Iterator it = dataCache.entrySet( ).iterator( );
	        while (it.hasNext())
	        {
	            Map.Entry entry = (Map.Entry)it.next();
	            IResultIterator iter = (IResultIterator) entry.getValue();
	            if( null == iter)
	            	continue;
	            try
				{
					IQueryResults iresult = iter.getQueryResults();
					iter.close( );
					iresult.close( );
				}
				catch ( BirtException ex )
				{
					log.log( Level.WARNING, ex.getMessage( ) );
				}
	        }
			dataCache.clear( );
			dataCache = null;
		}
		super.close( );
	}
	private boolean isCascadingParameter( ScalarParameterHandle parameter )
	{
		return parameter.getContainer( ) instanceof CascadingParameterGroupHandle;
	}
	private Object[] getParameterValuesAhead( ScalarParameterHandle parameter )
	{
		assert isCascadingParameter( parameter );