[keeperofdakeys]

Postgres has some disadvantages that can pop up on certain workloads (eg. bloat) but so does MySQL. And most of those limitations are only when you've got long open transactions, trying to hammer it IO wise, or you're making really big databases (100GB-1TB or more). However for both Postgres and MySQL there is plenty of documentation about these problems, and how to resolve them. So you'll never be "stuck" with issues.

In general I find postgres "just works" a lot more than MySQL. MySQL has a really bad habit of sticking with bad defaults for a long period, while having better configuration available. On the other hand postgres devs actively remove/change defaults so you're always getting the best it has to offer.

If you pick one, and you don't like it there are plenty of tools to change between them. If you're curious you could even deploy both of them.