如果表每天有超过50,000条记录，如何优化此查询？

Question

select count(1) total 
from Leads 
where originaldate = curdate() and campaign = 78;

我已经索引了该表的原始日期列

Answer 1

INDEX(campaign, originaldate)

假设orignaldate的类型为DATE，则该复合索引可以采用任意顺序。