Managing Image Files: database size limits?

Hi,

if I decided to build a solutions meant to store and organise Image files, how big the database could become before I encounter problems (poor perfomance, file size limits and so on)?

Of course, I don’t want to put the original files into the database (I was thinking of 128x128 or 256x256 thumbnails) and I wanted to use MySQL as backend.

Thanks

Please ask the MySQL guys, we are not into the details of each db.