Text files vs MySQL. Which is better for storing wiki information

I have been storing my wiki information in a MySQL database. However, 开发者_StackOverflowit seems like kind of a waste to store huge amounts of info in a relational database. I am thinking of moving the bulk of the information to text files. Does anyone have experience with which would be better?

Why you want do that,
if you do that, how you can perform search on your wiki?
a wiki post should be processed to build blue links and red links, how you want do that in text file?
after processing wiki post it's good to cache it in text file, we have a large wiki and store processed wiki in another table, its very fast.