php面试题之sql语句优化

今天去了一家公司面试，进展算是很顺利，但是在笔试的时候，一道sql语句优化的题目让我懵了，题目如下：
例子1:
SELECT * FROM order WHERE YEAR(orderDate)<2008;(慢)
SELECT * FROM order WHERE orderDate<"2008-01-01";(快)
例子2:
SELECT * FROM order WHERE addtime/7<24;(慢)
SELECT * FROM order WHERE addtime<24*7;(快)
例子3:
SELECT * FROM order WHERE title like "%good%";
SELECT * FROM order WHERE title>="good" and name<"good";
看来是的认真的学下mysql了！