数据库分表设计思想:
http://wenku.baidu.com/view/3e6685323968011ca300915d.html
http://www.cnblogs.com/zhangji/archive/2010/09/09/1822177.html
http://blog.sina.com.cn/s/blog_6e322ce70100zs9a.html
http://blog.youkuaiyun.com/yycai/article/details/4423882
http://wenku.baidu.com/view/3e6685323968011ca300915d.html
http://www.cnblogs.com/zhangji/archive/2010/09/09/1822177.html
http://blog.sina.com.cn/s/blog_6e322ce70100zs9a.html
http://blog.youkuaiyun.com/yycai/article/details/4423882