Earlier quoted context omitted.
And I recall the last time I looked at the source (when it was released with Arc), it didn't use a database either. All the data is stored as files.
A link to (possibly an old version of) the source for those interested: https://github.com/nex3/arc/blob/master/lib/news.arc
I'd love to see my median karma on my profile. Much more robust to outliers than average.