Bug 180189 Support in memory data set cache.
Currently, Design-Time Data Cache is stored on disks. By performance tests using ramdisk, we found that caching in physical memory can improve the performance of RunAndRender by 30%.
data/org.eclipse.birt.data.tests/test/org/eclipse/birt/data/engine/binding/DataSetCacheTest.java
bindingExprGroup[0] = new ScriptExpression( "dataSetRow.CITY" );
		GroupDefinition[] groupDefn = new GroupDefinition[]{
			new GroupDefinition( "group1" )
		};
		groupDefn[0].setKeyExpression( "row.GROUP_CITY" );
		groupDefn[0].setInterval( IGroupDefinition.STRING_PREFIX_INTERVAL );
		qd.addResultSetExpression( bindingNameGroup[0], bindingExprGroup[0] );
		qd.addGroup( groupDefn[0] );
		String[] columnStr = new String[]{
				"Country", "City", "date", "amount"
		};
		String outputStr = getOutputStrForGroupTest( 30,
				qd,
				0,
				bindingNameRow,
				columnStr );
		testPrint( outputStr );
		this.checkOutputFile( );
		getDataSetCacheManager( myDataEngine ).resetForTest( );
	}
	/**
	 * @throws BirtException
	 */
	public void testUseAppContextCacheRowLimit1( ) throws BirtException, Exception
	{
		this.dataSet.setCacheRowCount( 100 );
		DataEngineContext dec = DataEngineContext.newInstance( DataEngineContext.DIRECT_PRESENTATION,
				null,
				null,
				null );