I first heard about Datomic shortly after it was initially
released. I think I almost immediately went and read all of the
Relevance Cognitect released about
it’s architecture. I was duly impressed, and really interested in
using it. In particular, the potential for
time-travelling was really interesting and
exciting to me.
At the time I had been tasked with writing some code to determine usage metrics for our system. One of my boss’s hopes was that we could generate usage data from some time ago as well to compare with our current levels. Because we were using traditional relational databases and hadn’t planned for this use case, that turned out to be impossible. However, if we had been using Datomic, that back-dated query would have been absolutely trivial.