How to implement tag system

Question

I was wondering what the best way is to implement a tag system, like the one used on SO. I was thinking of this but I can\'t come up with a good scalable solution.

I

Answer 1

Nothing wrong with your three-table solution.

Another option is to limit the number of tags that can be applied to an article (like 5 in SO) and add those directly to your article table.

Normalizing the DB has its benefits and drawbacks, just like hard-wiring things into one table has benefits and drawbacks.

Nothing says you can't do both. It goes against relational DB paradigms to repeat information, but if the goal is performance you may have to break the paradigms.