摘要: 一、Spark 为什么比 MapReduce 要高效? 举一个例子: select a.state,count(*),AVERAGE(c.price) from a join b on (a.id=b.id) join c on (a.itemId=c.itermId) group by a.sta 阅读全文
posted @ 2018-02-24 17:36 oftenlin 阅读(162) 评论(0) 推荐(0) 编辑