I'm designing a mysql database, and i'd like some input on an efficient way to store blog/article data for searching.

Right now, I've made a separate column that stores the content to be searched - no duplicate words, no words shorter than four letters, and no words that are too common. So, essentially, it's a list of keywords from the original article. Also searched would be a list of tags, and the title field.

I'm not quite sure how mysql indexes fulltext columns, so would storing the data like that be ineffective, or redundant somehow? A lot of the articles are on the same topic, so would the score be hurt by so many of the rows having similar keywords?

Also, for this project, solutions like sphinx, lucene or google custom seach can't be used -- only php & mysql.

Thanks!