Database engine in PHP

Hi, I have already asked this question, but I think I wasn't clear enough of my intentions (thanks for all your responses anyway) I was wondering if there is any DBMS, like MySQL, which is (fully) implemented in php. That is a database engine written in PHP. I know this is not the most effecient way, but I'm not planning to use it for heavy weight database-driven-application. I just want a way to store simple data and I thought that SQL would be a nice interface. Since it could be easelly ported to mysql (for which I have to pay my host). Full SQL support is'n needed either. Just some basis queries. Maybe it very ineffecient, but I think basic SQL will be fast enough (with not to many records (say 50)). Who knows maybe I am crazy :-P greetings