Why not move Airbnb&#x27;s message inbox tables from MySQL to a new database, like Apache Cassandra[1], that&#x27;s much easier to scale horizontally?<p>[1]: <a href="https:&#x2F;&#x2F;cassandra.apache.org&#x2F;" rel="nofollow">https:&#x2F;&#x2F;cassandra.apache.org&#x2F;</a>