As a DBA who works with both MySQL and Postgres, I strongly prefer managing recent versions of MySQL for large SaaS systems. Postgres has significant issues wi

As a DBA who works with both MySQL and Postgres, I strongly prefer managing recent versions of MySQL for large SaaS systems. Postgres has significant issues with vacuum and index write amplification, as noted in the Uber blog post a few years ago - nothing has changed. Additionally, there is no clear compliance story regarding schema configuration, grants and restricting COPY with Postgres, while those are no-brainers with MySQL. If you're an AWS user, then MySQL has more advanced managed options as of 2019. In summary, Postgres is fine if you don't have paying users yet - any database would do fine. But there's a reason Google and Facebook have stayed with MySQL, and that's because it is manageable at scale whereas Postgres simply isn't. On the other hand, if you want to use Vertica (derived from the Postgres code base) as a column-store database, then managing it is the same as Postgres.