database design - MySQL: Using DATETIME as primary key

Question

My database will be storing a large number of data points, so I am using an unsigned BIGINT as the primary key.

Would it ever make sense to use a DATETIME object as the primary key?

Thanks,

Answer 1

Yes if course it makes sense for a date/time to be a key or part of a key if you need to uniquely identify discrete points or periods of time. I can't say if that applies to your scenario but as a general rule there's no fundamental reason why keys can't be based on time - almost any data warehouse does it.