Going with something like sqlite is not always better -- if what it provides is not needed, it's complexity for complexity's sake. PHP arrays are perfectly fine (until you reach a certain size), particularly when using a direct key access scheme. Loading/saving the data is pretty much a file_get_contents|file_put_contents affair, with some inline filters such as serialize & gzip. Couldn't be simpler, and it sounds like it doesn't need to be more complex than that.