数据库设计就是设计程序所需数据的类型、格式、长度和组织方式。因为数据库应用系统主要是处理大量的数据，所以数据库设计的优劣，直接影响整个数据库应用系统的性能和执行速率。 -Database design is the design program desired data type, format, length and organization. Database application system to process large amounts of data, the pros and cons of the database design, directly affect the performance of the entire database application system and execution rate.