如果说简单聚合是对一些特定统计需求的实现，那么 reduce 算子就是一个一般化的聚合统计操作了。从大名鼎鼎的 MapReduce 开始，我们对 reduce 操作就不陌生：它可以对已有的
I have a problem with a custom built ASP.NET MVC2. The strongly-typed views break as the viewdata is treated as \'Object\' instead of the corresponding type.
加载中,请稍侯......