What is the most efficient way to store tags in a database?

Question

I am implementing a tagging system on my website similar to one stackoverflow uses, my question is - what is the most effective way to store tags so that they may be searche

Answer 1

If space is going to be an issue, have a 3rd table Tags(Tag_Id, Title) to store the text for the tag and then change your Tags table to be (Tag_Id, Item_Id). Those two values should provide a unique composite primary key as well.