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/src/org/eclipse/birt/data/engine/impl/DataSetCacheUtil.java
}
			}
			
		}
		
		int realCacheOption;
		
		if ( cacheOption == DataEngineContext.CACHE_USE_ALWAYS )
		{
			realCacheOption = DataEngineContext.CACHE_USE_ALWAYS;
		}
		else if ( cacheOption == DataEngineContext.CACHE_USE_DISABLE )
		{
			realCacheOption = DataEngineContext.CACHE_USE_DISABLE;
		}
		else if ( appContext != null )
		{
			Object option = appContext.get( DataEngine.DATASET_CACHE_OPTION );
			if ( option != null && option.toString( ).equals( "true" ) )
				realCacheOption = DataEngineContext.CACHE_USE_DEFAULT;
			else
				realCacheOption = DataEngineContext.CACHE_USE_DISABLE;
		}
		else
		{
			realCacheOption = DataEngineContext.CACHE_USE_DISABLE;
		}
		return realCacheOption;
	}
	/**