disclaimer: I work for Citus Data<p>The bottleneck is usually not I&#x2F;O, but computing aggregates over data that continuously gets updated. This is quite CPU intensive even for smaller data sizes.<p>You might want to consider PostgreSQL, with Citus to shard tables and parallelise queries across many PostgreSQL servers. There&#x27;s another big advertising platform that I helped move from MySQL to PostgreSQL+Citus recently and they&#x27;re pretty happy with it. They ingest several TB of data per day and a dashboard runs group-by queries, with 99.5% of queries taking under 1 second. The data are also rolled up into daily aggregates inside the database.<p>There are inherent limitations to any distributed database. That&#x27;s why there are so many. In Citus, not every SQL query works on distributed tables, but since every server is PostgreSQL 9.5, you do have a lot of possibilities.<p>Looking at your username, are you based in the Netherlands by any chance? :)<p>Some pointers:<p>- How CloudFlare uses Citus: <a href="https:&#x2F;&#x2F;blog.cloudflare.com&#x2F;scaling-out-postgresql-for-cloudflare-analytics-using-citusdb&#x2F;" rel="nofollow">https:&#x2F;&#x2F;blog.cloudflare.com&#x2F;scaling-out-postgresql-for-cloud...</a><p>- Overview of Citus: <a href="https:&#x2F;&#x2F;citus-conferences.s3.amazonaws.com&#x2F;pgconf.ru-2016&#x2F;CitusDB.pdf" rel="nofollow">https:&#x2F;&#x2F;citus-conferences.s3.amazonaws.com&#x2F;pgconf.ru-2016&#x2F;Ci...</a><p>- Documentation: <a href="https:&#x2F;&#x2F;www.citusdata.com&#x2F;documentation&#x2F;citusdb-documentation&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.citusdata.com&#x2F;documentation&#x2F;citusdb-documentatio...</a>