There is a folder on my computer as well, with the name of the scheme, calles "measurement1" for example. In this folder, there is the data of the tables, for each table one file with the same name and the ending ".frm". This files are about 9 KB. There is another file, called db.opt, which is 1 KB. I have no idea what this file is about. But the stored data is not in this folder, because I stored about 2 GB data. The file "ibdata1" in the folder "data" is about 2 GB, so I guess the data is there. But thats not what I want, because the data of every scheme is stored in this file. But I wan't seperate folder with the data for every session. So maybe I should try to install an older version of MySQL?!