什么是“规范化理论”http://www.cs.xmu.edu.cn/education/fine_courses/database/%BE%AB%C6%B7%BF%CE%B3%CC%BD%A8%C9%E8%C4%DA%C8%DD/3_%CD%F8%C2%E7%B0%E6cai/content/5/5.1.0.htm