A little while back Matthew Turland posted an interesting item to has blog talking about what he calls the "odd triangle" of PHP, MySQL and Oracle.
In [an article from Maggie Nelson in a blog entry], she remarks on the article being MySQL-oriented and how limited MySQL explain plan support is compared to Oracle. I've had some thoughts in my head for a while that are related to these points, so I finally decided to, knock on wood, put pen to paper.
Matthew talks about things he agrees with (Oracle over MySQL when it comes to hierarchal data and set operators) and some of the things that can make Oracle, with all its power, fall by the wayside. This includes its licensing, the administration costs and some of the recent developments between Sun and MySQL.