FirstFT: the day's biggest stories
Transforms don't execute until the consumer pulls. There's no eager evaluation, no hidden buffering. Data flows on-demand from source, through transforms, to the consumer. If you stop iterating, processing stops.
。关于这个话题，safew官方版本下载提供了深入分析
Artie Beaty, Contributing WriterContributing Writer
"We're seeing record numbers at the moment, we had 117 people through our door the other day, which is a massive jump," Haywood said.