Another important gotcha (or maybe it ain't a gotcha but something common) is something I've recently came across. When performing a search through a fulltext index against a phrase, only words equal longer than 4 symbols will be searched. This way if you search for "dye" in a table containing fields with values "red dye" and "green dye", you won't get the expected results.

I'm not very experienced in MySQL, it looked repelling to me from the first time I had a chance to work with it. It's off the standards, unpredictable, somewhat bloated.