mysql索引简谈 一、什么是索引 就好比我们在看一本书的时候，有目录的话，我们可以快速定位到想看的地方，而没有目录的话，我们只能一页一页地翻。索引就像目录，有了索引，数据库可以快速查询到目标内容&#…

一、原题 Which two statements are true regarding indexes? (Choose two.) A. They can be created on tables and clusters. B. They can be created on tables and simple views. C. You can create only one index by using the same columns. D. You can create more t…