CMXBTree 的主要作用是在内存中建立一棵B+树，主要针对数据量较大，查询频繁的数据。总之，CMXBTree 可被视作一个在内存中的数据库使用。其特点是：短小精悍。-CMXBTree major role in the establishment of a memory B-tree, mainly larger volume of data, inquiries frequent data. In short, CMXBTree be deemed to be a memory in the database used. Its features are : short and pithy.