ID for tags in tag systems

Question

I\'m implementing a tag system similar to StackOverflow tag system. I was thinking about when storing the tags and relating to a question, that relationship will be directly wit

Answer 1

Your last sentence in your question seems to answer it. Assuming the tags are stored in a tag table, I would always have an ID column (int or GUID) and the varchar/string column for the tag name. The many-to-many (junction table) that would relate some other entity to one or more tags would have two columns containing the ID's the "other entity" and the tag's ID. It's then easy to edit a tag (to correct a mis-spelling for example) without touching the key. You should get much better performance when using queries that include joins with your junction table and it also means you're normalizing your data better.

Remember, "the key, the whole key and nothing but the key, so help me codd"! :)