what's the fastest data storing/access to small amounts of data?

I want to make a minimalistic banner rotation and management script.
The only data i need a table ( it can be an array, a db table or something ) with the html code and a conter for each banner.

This will be used in a pretty high traffic site so it would need to be optimized. What would you guys sugest?

A sqlite database? A text file with a serialized array? Which one would be faster? I will need to update the counter every pageview.

Punnbb, for example, uses cache, that looks like a fast option. How do i do something similar? Like... dump variable value assignments in php to a file? Is there any quick way to achieve that? Don't know if i made myself clear...