[bojanz]

I am going to be controversial for a hot second, and say that in many ways MySQL is a more advanced and better implemented database at its core. Disclaimer: as a developer I love and prefer Postgres. But I've been on many projects where MySQL won for ops-related reasons.

Postgres has a MVCC implementation that is recognized as inferior[0] to what MySQL and Oracle do, and requires dealing with vacuuming and all of its related problems.

Postgres has a process-based connection model that is recognized as less optimal than the thread-based one that MySQL has. There are ongoing efforts[1] to move Postgres to a thread-based model but it's recognized as a large and uncertain undertaking.

Other commenters have also explained the still very noticeable difference in replication support, the lack of query planner hints, the less intuitive local tooling.

One thing to keep in mind is that both databases keep evolving, and old prejudices won't take us far. Postgres is improving its performance and replication support with each release. MySQL 8.0 added atomic DDL and a new query planner (MariaDB did their own query planner rework in 11.0, widening their differences). Both are improving their observability. So the race is far from over. But I definitely wouldn't count MySQL out.

[0] https://ottertune.com/blog/the-part-of-postgresql-we-hate-th... [1] https://www.postgresql.org/message-id/flat/31cc6df9-53fe-3cd...