I think Datomic which has been doing time series data for years now answers the &quot;what’s the big deal&quot; question for me:<p>&quot;Given a value of the database, one can obtain another value of the database as-of, or since, a point in time in the past, or both (creating a windowed view of activity). These database values can be queried ordinarily, without having to make special queries parameterized by time.&quot; <a href="http:&#x2F;&#x2F;www.datomic.com&#x2F;rationale.html" rel="nofollow">http:&#x2F;&#x2F;www.datomic.com&#x2F;rationale.html</a><p>So in other words you get to see <i></i>exactly<i></i> how the whole database looked at any given moment through history (certain parallels with the blockchain I suppose).