If by "advanced in-database processing" you mean stuff like PostGIS, then yes PostgreSQL is the right approach. But for most people building web-apps to scale,

If by "advanced in-database processing" you mean stuff like PostGIS, then yes PostgreSQL is the right approach. But for most people building web-apps to scale, or established businesses who want to pick a solution and stick to it for basically ever, MySQL is much easier to scale. There's a ton of companies running MySQL at scale. I never heard of the same for Postgres, and for a long while I had an intellectual preference for Postgres as being the more "pure" implementation. Experience in the field showed me that MySQL, despite its flaws, is the name of the game. Further "evidence" by referring to other experienced folks who worked on scaling SQL databases, and MySQL is what's used and what folks have experience with: - https://twitter.com/Sirupsen/status/1602347646961606656 - https://blog.nelhage.com/post/some-opinionated-sql-takes/#my-personal-choice-mysql