Bug 180842 Config memory buffer size in data engine execution.
To tuning the performance, it is necessary for DtE to expose API for clients to config the size of memory it used to store the final result set. A new AppContext string, "org.eclipse.birt.data.cache.memory.size" is proposed. The new appcontext entry only accept positive integer as input, the unit of which would be MB.
data/org.eclipse.birt.data.tests/test/org/eclipse/birt/data/engine/binding/NestedQueryTest.java
*/
	private void addParameterToQueryCall(ScriptExpression expression)
	{
		
		ParameterDefinition inputParamDefn = new ParameterDefinition( "param1",
				DataType.INTEGER_TYPE,
				true,
				false );
		inputParamDefn.setPosition( 1 );
		inputParamDefn.setDefaultInputValue( "0" );
		( (OdaDataSetDesign) datasetCall ).addParameter( inputParamDefn );
		InputParameterBinding inputParamBinding = new InputParameterBinding( 1,
				 expression);
		queryDefnCall.addInputParamBinding( inputParamBinding );
	}
	
	/**
	 * Run nested query.
	 */
	private void runNestedQuery( ) throws Exception
	{
		IPreparedQuery preparedQueryCustomer = dataEngine.prepare( queryDefnCustomer );
		IPreparedQuery preparedQueryCall = dataEngine.prepare( queryDefnCall );
		ScriptContext scriptContext = new ScriptContext( );
		
		IQueryResults queryResultsCustomer = preparedQueryCustomer.execute( scriptContext.getScope( ));
		IResultIterator resultItCustomer = queryResultsCustomer.getResultIterator( );
		
		testPrintln( "*****A new Report Start!*****" );
		while ( resultItCustomer.next( ) )