If you just need to put some files online is it worth all the trouble to set a mysql database? Look at this example: http://demo.gnifi.com/anima_gallery/ This gallery is 100% Mysql Free...and works perfectly for small to medium websites, a true plug&play thing, you just upload and see it running
In many cases it's not necessary unless the software requires some sort of database connectivity. Sqlite is an excellent file based storage that works just like a database. Sqlite databases are extremely portable and are a very good match for small websites.
It might not be necessary, but handling writes/deletes using files can become tedious as well, you will need to create your own search/select type of queries which will take more work in general than setting up a db which has all of that built into it. Things can get unruly pretty quickly and a DB isn't something to be scared of. Backing up a DB is simple with mysqldump, restoring fairly simple as well. Don't re-invent the wheel, if you don't have to. A DB even on a small site can save you a lot coding time and debugging time.