Cookie与MySQL保存

Question

I guess this is more of just a personal preference questions, but I'm really concerned with performance. I'm working on a little project and one thing that people can do is RSVP to events. Now I know the option that people choose (attend or not attend) must be stored in a database, but to make the site look a little better, I also want the button that allows someone to attend switch to not attend when they click it.

At this point I'm thinking of three options, either query the database, figure out if the person is attending, and display the appropriate button. -OR- I could save the information in a cookie and just pray that the user doesn't delete the information. -OR- I could save the information in a cookie, if the cookie is present then display whatever the cookies says, if not then query the database. Option 3 seems the best to me.

I always kind of inspect major sites and look at some of the techniques they use. They tend to keep the cookie count under 20. Is there anything bad about option 3, or is it the way I should go. Thanks!

Answer 1

If you use cookie, you can expect that there is some other person who uses the same machine, the same user account, the same browser, the same settings. There can be also a person who uses different browsers. There can be also two persons who share two computers.

If the users log in you can use sessions, it is cookie, of course, but you can identify the user, so he knows "it's not me".

And about performance: if you set your cookie, it takes also time to get it and then send it, via http headers and responses. But the best idea would be to benchmark this. Because of the small time to access db and for the reasons I stated before, I would use the db.